GB1560693A - Machine tools particularly but not exclusively spinning lathes - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO MACHINE TOOLS, PARTICULARLY BUT NOT EXCLUSIVELY SPINNING TOOLS (71) We, FIRMA WILHELM POLL MEIER MASCHINENFABRIK, a German Kommanditgesellschaft, of Theodor Schwarte-Strasse 97, 4730 Ahlen/Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a machine tool for use in conjunction with numerical control equipment, and particularly but not exclusively to a spinning lathe for making symmetrical, circular, spun parts from prepared pieces such as discs or blanks, which lathe has a bed with a powered headstock for the workpiece, and a tailstock centred on the same axis for receiving the workpiece, and in radial proximity to the axis, supports for the work tools.

Spinning lathes of this type are known, whereby a contoured tool or chuck is used against which the disc is pressed and formed into shape by means of spinning tools such as pressure rollers.

On the known machines, the bed of the machine is arranged with the headstock at one end, and facing this, the tailstock towards the other end, usually on longitudinal guide means. The supports for the spinning tools are provided on the side of and protruding from the bed, normally freely adjustable. As a rule these supports and their guide means can be adjusted to any desired angle in relation to the centre axis of the machine. Auxiliary tools such as centering means or cutters are arranged on strands rigidly connected to the bed. Also, auxiliary tools with a single line of movement can be secured to the bed or to the headstock.

The known spinning lathes have the disadvantage that the basic adjustments of the tools, the spinning and the form or chuck in their relative positions are empirical adjustments. There are therefore many uncertainties involved when setting up the machine which depend upon the special skill of the fitter to obtain a useful set up.

It is for this reason not possible to adapt to a numerical control system by representing the procedure phases in exact numerical values. The necessary steps cannot be exactly reproduced because the known machines do not have machine-orientated, graduated adjustment but merely freely adjustable axes. A numerical control system is known in connection with an automatic highpower machine tool (see for example German laying open specification 1652631), in which a support with the operating tools is controlled by numerical values in connection with certain coordinates of its two axes. The numerical control begins at a point where, after all the other uncertainties of adjustment have been empirically eliminated, the remaining axes can be controlled by a two dimensional co-ordination system. The starting point for the numerical control system is determined by adjustment of the axes, which together with the adjustment of the auxiliary tools, mounting the disc etc. still requires a great deal of skill generally provided by the latent knowledge of the operator in the science for setting up known types of spinning lathes.

Furthermore the bed of such spinning lathes merely serves the purpose of taking the strain during the spinning operation.

It is an object of the present invention to obviate or mitigate these disadvantages.

According to the present invention there is provided a machine tool for manufacturing rotarily-symmetrical shaped parts and for control by numerical-control equipment, said machine tool, including a spindle carrying a workpiece receiving element and with a tool-holder adapted to carry several work tools which is movable along a longitudinal axis and along a transverse axis, for controlled guidance of a work tool, the tool-holder additionally being rotatable about an axis normal to said longitudinal and transverse axis for angular setting by the numerical control equipment whereby the tool holder can present tools, which individually engage on a workpiece at various rotary angular positions of the tool-holder, and whereby the workpiece presentation angle of a tool employed at any moment is adjustable during its movement along the longitudinal axis and the transverse axis by controlled rotary movements of the tool-holder so that a predetermined path of movement of the tool results from superimposition of linear movement and of the rotary movement of the tool-holder.

The above machine tool provides a novel arrangement of axes along which the moving parts of the machine are slid, so that a fine degree of purely axial control using numerical values can be achieved, eliminating (or reducing) setting-up adjustment of the axes.

A particular advantage of the machine tool according to the invention is that the strict right-angular co-ordination system of the axes of the spinning part mounting and of the moveable tool carriage make it possible to exactly position the tools by means of predetermined numerical values. All the usual uncertainties in the setting-up of the tools are reduced or eliminated, and the bed of the machine which previously served no other purpose, and which can be situated to one side of the centre axis serves to precisely guide the tool carriage.

In order to move spinning tools and auxiliary tools along at least four controlled axes, it is advantageous for the supports on the bed of the machine to consist of a main support with a longitudinal carriage, a cross slide and a revolving turret, and an auxiliary support with a longitudinal carriage and a cross slide.

A preferred arrangement thereof is to position the main support with the work tools to one side of the tailstock on the bed, and the auxiliary support with the auxiliary tools, such as disc rim holder and/or rim cutter, to one side of the headstock.

In order to increase the number of tools that can be brought to bear, it is useful to arrange the tools on the turret in two or more planes at right-angles to the axis, and to provide for axial adjustment of the turret to the extent of the distance between the planes.

The revolving support or turret can be equipped not only with the usual spinning tools but also with tools for special jobs, for example cutting tools.

Furthermore, the tailstock is preferably carried in guide means longitudinally arranged on the side of the bed.

For spinning, the spun part which began as a flat disc is often substantially elongated, and it is therefore an advantage that the tailstock is hinged to a carriage which runs in the longitudinal guide means on the side of the bed.

The axis of the hinge is preferably in the proximity of the lower, inner, longitudinal edge of the tailstock. On completion of the spun part, it is then possible to hinge the tailstock forwards and down leaving sufficient free space to remove an elongated spun part from the spinning form.

An especial advantage of the invention is to be found in the fact that numerical control of the carriage, cross slide and turret of the main support, and of the carriage and cross slide of the auxiliary support is achieved. Five axes are thus numerically controlled.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawing which is a schematic view of a spinning lathe according to the present invention.

Referring to the accompanying drawing, a spinning lathe has an elongated substantially flat bed 1 upon which straight, longitudinal guide means 2 are arranged. These guides 2 can be for example rounded guides whereon the moving parts are carried by means of bearings (not shown). The main tool support 3, consisting of the carriage 4 and the cross slide 5, is situated towards one end of the bed 1. The cross slide 5 runs in guides 15 on the carriage 4, which are arranged at right-angles to the guides 2 on the bed 1. A turret 6 rotatable about a vertical axis, has arms 9 for spinning tools 10 and is located on the cross slide 5.

The tools 10 can be arranged on the turret 6 in two or more horizontal planes. In order to bring the tools into position, the turret 6 is made vertically adjustable. The extent of the adjustment must logically correspond to the distance between the planes of the tools.

The tools 10 (not illustrated in detail in the drawing) are principally spinning tools.

Apart from these shaping tools however, cutting tools can also be used on the new machine.

A further advantage of the turret 6 is that the rotation thereof serves not only to bring a selected spinning tool into position, but serves also for motion during the spinning process in order to achieve a continuous follow-up of the tool.

An auxiliary support 11 with a carriage 12 and a cross slide 13 is also provided on the guide means 2 of the bed 1. The cross slide 13 runs in guides 16 which are parallel to the guides 15 for the cross slide 5 of the main support 3. Thus the guides 16 of the cross slide 13 are also at right angles to the guide means 2 on the bed 1. The cross slide 13 carries auxiliary tools 14 which can be for example a rim holder, or a rim cutter. All the other tools for the spinning operation are situated on the turret 6 of the main support 3.

The main tool support 3 and the auxiliary tool support 11 are positioned solely by means of a numerical control system. In the case of the present embodiment, this control extends over a total of five axes which are the direction of movement of the carriage 4 and the cross slide 5 of the main support 3, the carriage 12 and the cross slide 13 of the auxiliary support 11 and the rotation of the turret 6. If the vertical movement of the turret 6 is included, the number of controlled axes would be six. All combinations of movement within the scope of these axes can be translated into numerical values for computer control. Since systems for numerical control of this kind are well known, there is no need to describe the system in detail.

Briefly, it is of special importance that with this machine only rigidly machineorientated movements are possible. The crossing axes of the supports are subject to the numerical control system and need no longer be empirically adjusted. The rotary control of the turret can be determined in like manner whereby the rotation values can be translated into terms of arc or angular degree.

The headstock 17 which can be for example of the conventional type is situated at a side of the bed 1 as can be seen in the figure. Protruding from the headstock 17 is a spindle 18 which carries the spinning chuck 19. This centre spindle 18 is parallel to the longitudinal guide means on the bed of the machine. Thus the guides 15 and 16 for the cross slide 5 of the main support 3 and the cross slide 13 of the auxiliary support 11 are at right-angles to a vertical plane taken through the axis of the centre spindle 18.

The headstock 17 includes preferably a DC driving means for the centre spindle 18 with a wide range of control, for example 1:100, to eliminate the need for gear change. It is furthermore advantageous for the drive to operate with constant torque.

A tailstock 20 with a centre 21 is carried by a carriage 23 in longitudinal guide means 22 on the side of the bed 1. The tailstock centre 21 is, of course, co-axial to the spindle 18 and carries the article spinning blank which is not shown. The tailstock 20 is hinged to the carriage 23 as is shown in broken lines. It hinges thereby about an axis which is preferably in the proximity of its lower, inner, longitudinal edge. Especially long and thus awkward spun parts can be easily removed from the chuck 19 by swinging the tailstock down.

The chuck 19 can take the form of a conventional chuck. In the case of large mouthed spinnings, the chuck 19 can be distensed with and in its place a roller or the like operating in opposition to the spinning tool is used, which, on the above spinning lathe can be mounted on the controlled auxiliary support 11.

The tailstock 20, furthermore, is provided with a means for centering the disc or preformed part and, what is more important, a means for measuring the thickness thereof.

The special advantage achieved by this means is that the programmed course calculated by the numerical control system is not based on the nominal value for the initial thickness of the material but rather on the actual measurement thereof.

WHAT WE CLAIM IS: 1. A machine tool for manufacturing rotarily-symmetrical shaped parts and for control by numerical-control equipment, said machine tool including a spindle carrying a workpiece receiving element and with a tool-holder adapted to carry several work tools which is movable along a longitudinal axis and along a transverse axis, for controlled guidance of a work tool, the tool-holder additionally being rotatable about an axis normal to said longitudinal and transverse axis, for angular setting by the numerical control equipment whereby the tool holder can present tools, which individually engage on a workpiece at various rotary angular positions of the tool-holder, and whereby the workpiece presentation angle of a tool employed at any moment is adjustable during its movement along the longitudinal axis and the transverse axis by controlled rotary movements of the tool-holder, so that a predetermined path of movement of the tool results from superimposition of linear movement and of the rotary movement of the tool-holder.

2. A machine tool according to Claim 1, wherein the tool holder carries the tools located in several planes, and the toolholder is vertically movable in such a way that each tool plane can be brought to an attack level.

3. A machine tool as claimed in Claims 1 or 2, wherein a tailstock is provided carried in longitudinal guide means arranged on the side of the bed, the tailstock being hinged to a carriage running in the guide means on the side of the bed.

4. A machine tool as claimed in Claim 3, wherein the tailstock is hinged to the carriage about a bottom edge of the tailstock.

5. A machine tool substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. example a rim holder, or a rim cutter. All the other tools for the spinning operation are situated on the turret 6 of the main support 3. The main tool support 3 and the auxiliary tool support 11 are positioned solely by means of a numerical control system. In the case of the present embodiment, this control extends over a total of five axes which are the direction of movement of the carriage 4 and the cross slide 5 of the main support 3, the carriage 12 and the cross slide 13 of the auxiliary support 11 and the rotation of the turret 6. If the vertical movement of the turret 6 is included, the number of controlled axes would be six. All combinations of movement within the scope of these axes can be translated into numerical values for computer control. Since systems for numerical control of this kind are well known, there is no need to describe the system in detail. Briefly, it is of special importance that with this machine only rigidly machineorientated movements are possible. The crossing axes of the supports are subject to the numerical control system and need no longer be empirically adjusted. The rotary control of the turret can be determined in like manner whereby the rotation values can be translated into terms of arc or angular degree. The headstock 17 which can be for example of the conventional type is situated at a side of the bed 1 as can be seen in the figure. Protruding from the headstock 17 is a spindle 18 which carries the spinning chuck 19. This centre spindle 18 is parallel to the longitudinal guide means on the bed of the machine. Thus the guides 15 and 16 for the cross slide 5 of the main support 3 and the cross slide 13 of the auxiliary support 11 are at right-angles to a vertical plane taken through the axis of the centre spindle 18. The headstock 17 includes preferably a DC driving means for the centre spindle 18 with a wide range of control, for example 1:100, to eliminate the need for gear change. It is furthermore advantageous for the drive to operate with constant torque. A tailstock 20 with a centre 21 is carried by a carriage 23 in longitudinal guide means 22 on the side of the bed 1. The tailstock centre 21 is, of course, co-axial to the spindle 18 and carries the article spinning blank which is not shown. The tailstock 20 is hinged to the carriage 23 as is shown in broken lines. It hinges thereby about an axis which is preferably in the proximity of its lower, inner, longitudinal edge. Especially long and thus awkward spun parts can be easily removed from the chuck 19 by swinging the tailstock down. The chuck 19 can take the form of a conventional chuck. In the case of large mouthed spinnings, the chuck 19 can be distensed with and in its place a roller or the like operating in opposition to the spinning tool is used, which, on the above spinning lathe can be mounted on the controlled auxiliary support 11. The tailstock 20, furthermore, is provided with a means for centering the disc or preformed part and, what is more important, a means for measuring the thickness thereof. The special advantage achieved by this means is that the programmed course calculated by the numerical control system is not based on the nominal value for the initial thickness of the material but rather on the actual measurement thereof. WHAT WE CLAIM IS:

1. A machine tool for manufacturing rotarily-symmetrical shaped parts and for control by numerical-control equipment, said machine tool including a spindle carrying a workpiece receiving element and with a tool-holder adapted to carry several work tools which is movable along a longitudinal axis and along a transverse axis, for controlled guidance of a work tool, the tool-holder additionally being rotatable about an axis normal to said longitudinal and transverse axis, for angular setting by the numerical control equipment whereby the tool holder can present tools, which individually engage on a workpiece at various rotary angular positions of the tool-holder, and whereby the workpiece presentation angle of a tool employed at any moment is adjustable during its movement along the longitudinal axis and the transverse axis by controlled rotary movements of the tool-holder, so that a predetermined path of movement of the tool results from superimposition of linear movement and of the rotary movement of the tool-holder.

2. A machine tool according to Claim 1, wherein the tool holder carries the tools located in several planes, and the toolholder is vertically movable in such a way that each tool plane can be brought to an attack level.

3. A machine tool as claimed in Claims 1 or 2, wherein a tailstock is provided carried in longitudinal guide means arranged on the side of the bed, the tailstock being hinged to a carriage running in the guide means on the side of the bed.

4. A machine tool as claimed in Claim 3, wherein the tailstock is hinged to the carriage about a bottom edge of the tailstock.

5. A machine tool substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.