GB2106438A

GB2106438A - Lathe

Info

Publication number: GB2106438A
Application number: GB08225714A
Authority: GB
Inventors: Ernest Schmid
Original assignee: Edouard Dubied et Cie SA
Current assignee: Edouard Dubied et Cie SA
Priority date: 1981-09-11
Filing date: 1982-09-09
Publication date: 1983-04-13
Also published as: FR2512709A1; GB2106438B; IT8268079A0; DE3136017C1

Abstract

The lathe consists of a stationary headstock (3), a travelling tailstock (20) and at least three program- controlled machining units (11, 14, 17) with substantially identical construction. Each machining unit can travel horizontally and vertically without a collision. The symmetrical form of the base plate (23) of each machining unit permits its arrangement above and below the horizontal spindle axis and further permits the mounting, as desired, of a right-hand or left-hand side multiple toolholder or corresponding auxiliary device. <IMAGE>

Description

SPECIFICATION Lathe The invention relates to a lathe having a stationary headstock and a travelling tailstock, and having machining units which can be programcontrolled independently of one another and which are movable in a parallel and also in a perpendicular direction in relation to a horizontal spindle axis.

Such lathes are known and are partially described in more detail in the AT-PS 341.855 and the GB-PS 1 465 139.

Since these known lathes have two machining units which are independent of one another and disposed opposite one another, a simultaneous machining of a workpiece can take place to an increased extent or travel movements of the one machining unit can be effected within the main time of the others, provided a 3 or 4-shaft track control is used. This also applies to known lathes wherein two such machining units are present at the same side in each case.

The basic construction of previous lathes does not permit additional freely controllable machining units to be added, however, because a travel movement thereof, free of collision at the headstock and at the tailstock would no longer be ensured. The economical range of use of these machines is thus limited because no parts can be produced, for example, which render necessary the use of a steady rest control which can be programmed freely.

Also the very different formation and arrangement of the machining units of known machines does not contribute to reducing the manufacturing costs, because of the large number of parts.

According to the present invention there is provided a lathe having a machine bed, a stationary headstock and a travelling tailstock and having machining units which can be programcontrolled independently of one another and which are movable in a parallel and also in a perpendicular direction in relation to a horizontal spindle axis, characterised in that at least three machining units are present which are disposed at both sides of the spindle axis and to left and right on the machine bed and that the design of the machining units is substantially identical.

The lathe of the invention can be versatile in use with the greatest economy, achieve a high degree of machining accuracy and offer an optimum price/performance ratio.

Due to the novel arrangement of the machining units, the following can be achieved inter alia.

Qontrollability of more than 4 shafts according to a program, ~Increased work cycle by simultaneous machining, ~With the same basic construction of the machine, easier adaptation of the machining units to the particular case of use, ~Guarantee of being able to travel past headstock and tailstock.

In addition, the substantially identical construction of the machining units also offers the following advantages: ~Lower production expense because of fewer sorts of parts, ~Simplification in stocking and delivering spare parts, ~Ability to dismount toolholders and auxiliary devices according to the machining case.

One advantage of the construction of the lathe according to the invention which must not be overlooked consists in that for the rational production of excessively slim parts to be turned or for the machining of shafts alternately, any of the machining units which can be freely programmed can be provided with a steady rest device.

One construction of a lathe according to the invention with three machining units will now be described, by way of example, with reference to the accompanying drawings, in which:~ Figure 1 shows a diagrammatic illustration of the lathe in perspective view.

Figure 2 shows a simplified view, representing the construction and the arrangement of the machining units.

Figure 3 shows a section on the line Ill-Ill in Figure 2.

Figure 4 shows a view of the base plate of a machining unit.

The lathe illustrated in Figure 1 comprises a reinforced concrete base 1 to which the actual cast machine bed 2 is bolted at three points. The headstock 3 is rigidly connected to the machine bed 2.

A main drive motor drives, through precision belts (not illustrated) the belt pulley 4 of the work spindle 5, the spindle axis A lying horizontally.

Mounted on the front face 6, Figures 1 , 2, 3 of the vertically disposed machine bed 2, which should be regarded as symmetrical, are four hardened and ground guide bars 7, 8, 9, 10, which extend over the whole length of the machine bed.

One pair of guide bars 7, 8 and 9, 10 are each equally spaced above and below the spindle axis A.

The upper right-hand machining unit 11, which is composed essentially of a known compound slide together with a drive, is carried by the guide bars 7, 8 and can be driven in the direction of the axis Z by means of the drive motor 12, via toothed belt 1 2a and the threaded spindle 13, in accordance with a program.

The identical upper left-hand machining unit 14, which is disposed symmetrically with respect to the upper right-hand machining unit 11, is likewise carried by the guide bars 7, 8. The travel of this unit in the direction of the axis Z in accordance with a program, is effected, however, by means of the drive motor 15, via toothed belt 1 5a and the threaded spindle 16. The same applies to the lower right-hand machining unit 17, which is disposed completely symmetrically to and is identical to the upper right-hand machining unit 11, but it is carried by the guide bars 9, 10 and can be controlled, likewise in the direction of the axis Z, via the drive motor 18, toothed belt 1 8a and threaded spindle 19.

The conpact tailstock 20 is carried by the two middle guide bars 8, 9 and, just like all the machining units, can be driven in the direction of the axis Z, without coming into contact with the machining units. This purpose is served by drive motor 21, toothed belt 21 a and threaded spindle 22.

Each of the said machining units 11,14,17 had an identical construction in which only the individual elements assume a different position.

Let us first consider the machining unit 11, in Figures 2 and 3.

A symmetrical base plate 23, which is rigidly connected to the bottom slide 24, contains a needle-guided top slide 25 which can again be moved in the direction of the axis X, controlled by a program, by a drive motor 26 disposed vertically, via toothed belt 26a and a threaded spindle 27.

In this machining unit, connected to the top slide 25 is a turret head 28 which receives the tools necessary for the machining. Its horizontal turret axis lies precisely parallel to the spindle axis A. Since the indexing and control of such a tool turret are known, a further description can be dispensed with.

The machining unit 14, Figure 2, corresponds precisely to the construction of the machining unit 11 with the only difference that it is laterally reversed. Seen thus, the drive motor 26 is on the left-hand side and the top slide 25 is disposed at the right-hand side of the symmetrical base plate 23.

Furthermore, it is made clear that instead of a tool turret 28, a self-centering steady rest 29 can be fitted, without having to alter the construction of the machining unit.

The symmetry of all the receiving bores in the base plate 23, illustrated in Figure 4, and the corresponding construction of the elements to be accommodated render possible for the manufacturer a cost-saving interchangeability of the machining units, which must not be underestimated, and of which the user can also take advantage in operation and in maintenance.

The invention is not restricted to the preferred form of embodiment in the specification, and, in particular, a further machining unit can be added at the left below the spindle axis if a further increase in the production possibilities is necessary.

Also, the machine can be distributed so that the fixed headstock is at the right-hand side of the operating position.

Claims

1. A lathe having a machine bed, a stationary headstock and a travelling tailstock and having machining units which can be program-controlled independently of one another and which are movable in a parallel and also in a perpendicular direction in relation to a horizontal spindle axis, characterised in that at least three machining units (11,14,17) are present which are disposed at both sides of the spindle axis (A) and to left and right on the machine bed (2) and that the design of the machining units is substantially identical.

2. A lathe as claimed in claim 1, characterised in that the machining units disposed above and below and on the right and on the left are symmetrical to one another in pairs (11, 17 and 11,14).

3. A lathe as claimed in claim 1, characterised in that each machining unit (11, 14, 17) comprises a bottom slide (24) and a top slide (25), that associated with the bottom slide (24) is a base plate (23) with securing elements fitted symmetrically, and that the top slide (25) is mounted on the base plate (23) using the securing elements corresponding to the particular position of the machining unit.

4. A lathe as claimed in claim 1 , characterised in that a drumlike multiple toolholder (28), the horizontal axis of which extends parallel to the spindle axis (A), can be mounted on each machining unit (11, 14,17) at the right-hand side or left-hand side.

5. A lathe as claimed in claim 1, characterised in that each machining unit (11, 14, 17) can be provided with auxiliary devices, for example a steady rest device (29), at the right-hand side or left-hand side.

6. A lathe as claimed in claim 1, characterised in that the drive devices serving for the control of the machining units, in accordance with a program, in a direction parallel to the spindle axis (A) are substantially identical.

7. A lathe as claimed in claim 6, characterised in that the drive devices 13,15,16,18,19) are disposed at both ends of the symmetrical machine bed (2).

8. A lathe as claimed in claim 1, characterised by four machining units disposed on the machine bed.

9. A lathe as claimed in claim 1 having two upper and two lower guides (7, 8, 9, 10) extending parallel to the spindle axis (A) for the machining units (11,14, 17), characterised in that the two middle guides (8, 9) additionally carry the tailstock (20) which can travel freely between the upper and the lower machining units.

10. A lathe substantially as hereinbefore described with reference to the accompanying drawings.