WO2001089759A1

WO2001089759A1 - Centre for machining workpieces

Info

Publication number: WO2001089759A1
Application number: PCT/IT2000/000211
Authority: WO
Inventors: Vinicio De Moliner
Original assignee: Pade S.A.S. Di De Moliner Vinicio & Co.
Priority date: 2000-05-23
Filing date: 2000-05-23
Publication date: 2001-11-29
Also published as: AU5101400A

Abstract

In a centre (10) for machining workpieces in general, provided with a unit (15) for machining the pieces and tables (19, 20; 27, 29) for supporting the pieces, in which the machining unit (15) is movable along two perpendicular translation axes (X, Z) and about two rotation axes (A, B), and in which the machining unit and the support tables are movable with relative motion along a third translation axis (Y1; Y2) perpendicular to the two above-mentioned translation axes (X, Z), the support means (19, 20; 27, 29) are constituted by at least a first support table and a second support table (20) which are spaced apart, and at least a third support table (19) which is disposed between the other two and is movable relative thereto in order to vary the support configuration, so that one or more pieces of various shapes and sizes can be supported and machined effectively and completely in a single machining step.

Description

DESCRIPTION "Centre for machining workpieces"

The subject of the present invention is a centre for machining workpieces in general . Centres for machining wooden workpieces, which provide for at least one head for machining the workpieces and which provide for one or more support tables on which the pieces to be machined are gripped, are known. The machining head, which comprises a plurality of chucks carrying the machining tools, is movable along two perpendicular translation axes and about two rotation axes; moreover, the machining unit and each support table are movable with relative motion along a third translation axis perpendicular to the two above- mentioned translation axes.

These centres operate in accordance with a numerical control program and can perform several operations on the piece in a single step, that is, it is possible to produce profiles, milled pieces, holes, tenons, mortises, etc.

An important part of a centre of this type is constituted by the support tables, which have to satisfy conflicting requirements.

In fact, the support tables have to support the pieces firmly and, at the same time, have to allow the head to move around the piece in order to perform the machining; this means that the support tables have to be of an extent such as to restrain the piece as much as possible, but must not be too large, in order not to interfere with the machining head.

It should also be stated that the pieces to be machined often differ from one another greatly in shape and in size and the support table may therefore be suitable for supporting pieces of some types but unsuitable for supporting pieces of other types.

The object of the present invention is to propose a centre in which it is possible to support and machine one or more pieces of various shapes and sizes effectively and completely in a single machining step . This object is achieved by means of a centre for machining workpieces in general, comprising at least one machining unit having means for machining the pieces and also comprising means for supporting the pieces, the support means being operatively associated with the machining unit, in which the machining unit is movable along two perpendicular translation axes and about two rotation axes, and in which the machining unit and the support means are movable with relative motion along a third translation axis perpendicular to the two above- mentioned translation axes, characterized in that the support means comprise at least a first support table and a second support table which are spaced apart, and at least a third support table which is disposed between the first and second support tables and is movable relative thereto in order to vary the support configuration.

The invention will be understood better from the following description of an embodiment thereof illustrated by way of example in the appended drawings, in which: Figure 1 is a perspective view of a centre according to the invention.

Figure 2 shows a detail of the machining centre of Figure 1 in partial longitudinal section,

Figures 3, 4, and 5 show a portion of the machining centre of Figure 1 in different operative positions, and

Figure 6 shows a variant of a portion of the machining centre of Figure 1.

The centre for machining workpieces of Figure 1, which is generally indicated 10, comprises a portion 10A belonging to the actual machining unit and a portion 10B belonging to the tables for supporting the workpieces to be machined.

The portion 10A comprises a support structure 11 along which a pillar 12 is slidable along a horizontal translation axis X. A slide 13 in turn is mounted on the pillar 12 for sliding along a vertical translation axis Z. An arm 14 extends from the slide 13 and rotates relative to the slide 13 about a rotation axis as indicated by the double arrow A. A head 15 carrying four chucks 16 which are arranged at 90° to one another and each of which can receive a machining tool, is mounted at the free end of the arm 14; the head 15 rotates relative to the arm 14 about a rotation axis as indicated by the double arrow B. The portion 10B comprises two guide bases 17 along each of which a respective carriage 18 slides. The right- hand carriage 18 in Figure 1 slides along a horizontal translation axis Y. and the left-hand carriage slides along another horizontal translation axis Y₂. These axes Y. and Y₂ are parallel to one another and perpendicular to the axes X and Z.

Three elongate, rectangular support tables are mounted on each carriage 18, parallel to one another and to the respective carriage sliding axis Y_x or Y₂; the larger central support table is indicated 19 and the lateral support tables are indicated 20.

Each support table 19 or 20 is provided with two hollow legs 21 fixed to the support table, which are coupled slidably with a "U" -shaped pillar 22 fixed to the carriage 18 and disposed between the legs 21. As shown in Figure 2, inside one of the arms of the pillar 22, there is a pneumatic cylinder 23, fixed to the pillar and having an actuating rod 24 the end of which is fixed to the lower side of the support table. The pneumatic cylinder 23 enables the support table to be raised relative to the pillar 22 by means of the actuating rod 24 of the cylinder, as shown in broken outline in Figure 2. The slidable coupling of the legs 21 with the pillar 22 is achieved by means of two profiled elements 25 of the legs, one for each leg, which extend throughout the height of the legs and which engage two respective shaped blocks 26 fixed to the two arms of the pillar 22 and having profiles complementary with the profiles of the two profiled elements 25. The centre 10 comprises a series of motors which move the components described above along the axes X, Y.., Y₂, Z and about the rotation axes of the double arrows A, B and which rotate the chucks .

The motors are operated by a suitable electronic operating and control unit which operates in accordance with numerical control programs .

The pneumatic cylinders 23 which raise and lower the support tables 19 and 20 are connected to a suitable pneumatic operating system of the centre 10. The upper surfaces of the support tables 19 and 20 are perforated (the holes are not shown for simplicity) and the holes are connected to suction members so as to create suction on the support table, for holding the piece to be machined on the table. These support tables 19 and 20 may have suitable elements for gripping the pieces, as an alternative or in addition to gripping by suction.

The machining centre 10 operates as follows.

The piece or pieces to be machined are loaded onto one or more support tables 19 and 20 belonging to one of the two carriages 18 and are gripped suitably on these support tables .

The carriage 18 with the pieces is advanced along the axis Y. or Y₂, according to the carriage used, towards the portion 10A of the machining centre 10 belonging to the machining unit . The machining head 15 is also moved along the axes X and Z in order to be brought into the vicinity of the piece or pieces to be machined.

For the machining, as is known, the arm 14 is rotated in accordance with the double arrow A and the head 15 is rotated in accordance with the arrow B, in order to select the direction of machining (from the front/from above/from below, laterally, obliquely) and the tool required, respectively. The required machining is then performed by moving the machining head 15 along the axes X, Z and the carriage 18 along the axis Y₁ or Y₂ in accordance with a predetermined numerical control program.

During this machining of the pieces, the support tables 19 and 20 carried by the other carriage 18 can be loaded with new pieces to be machined. When the machining is completed, the first carriage 18 is retracted and the other carriage 18 is advanced, and the head 15 is brought into its vicinity in order to machine the new pieces. The pieces already machined on the support tables 19 and 20 of the first carriage 18 can be discharged and these support tables are ready to be loaded with new pieces to be machined.

The two carriages 18 are moved alternately and successive machining operations are thus performed on new pieces .

By virtue of the support tables 19 and 20 and of their ability to be raised and lowered, it is thus possible to support and to machine one or more pieces of various shapes and sizes effectively and completely in a single machining step, satisfying the conflicting requirements described in the introduction.

Pieces of narrow and elongate shape can be arranged on the lateral support tables 20 and wider pieces can be supported on the central support table 19. The pieces may also be arranged transversely so that each piece is gripped on several support tables, a good support surface in any case being available . A single large piece may also be gripped on several support tables and, in this case also, a good support surface is available.

With reference to their ability to be raised or lowered, the support tables 19 and 20 can give rise to various support configurations, three of which are illustrated in Figures 3, 4, and 5, with reference to one of the two carriages 18 of Figure 1.

In the case of Figure 3 , in which the support tables 19 and 20 are in the lowered position, it is possible to arrange pieces of considerable height on the support tables. Normally, in known machining centres, tall workpieces cannot be machined because it is necessary to go beyond the upper limit of the vertical travel of the machining head along the axis Z; in the embodiment described, it is possible to remain below the upper limit of the machining head, even for tall workpieces, by keeping the support tables low.

In the case of Figure 4, in which the central support table 19 is in the lowered position and the lateral support tables 20 are in the raised position, it is possible to grip pieces on the two raised lateral support tables 20 and the machining head 15 can perform lateral machining operations on the pieces, even in the region of the inner sides of the lateral support tables 20, since the central support table 19 is lowered and does not interfere with the machining head. In the case of Figure 5, in which the central support table 19 is in the raised position and the lateral support tables 20 are in the lowered position, the workpiece can be gripped on the central support table 19 and the machining head 15 can also perform lateral machining operations around the piece since the lateral support tables 20 are lowered and do not interfere with the machining head.

Clearly, there are other support configurations; in particular, all of the three support tables 19, 20 may be in the raised position, or the central support table 19 and one lateral support table 20 may be in a lowered position and the other lateral support table 20 may be in a raised position, or vice versa .

Naturally, each support table 19 or 20 can be brought to and kept in an intermediate position between the fully lowered position and the fully raised position, in order to support the piece or pieces .

The possibility of the support tables 19 and 20 being raised or lowered during the machining, in combination with the head 15, in order to perform a machining operation is not excluded.

Figure 6 shows a variant of the portion of the machining centre belonging to the support tables. Instead of the arrangement described above, two lateral support tables 27, supported by two fixed pillars 28, are mounted on one of the carriages 18; in this variant, the two support tables are again elongate and rectangular and are parallel to one another and to the translation axis of the carriage 18. A third support table 29, also rectangular but of larger dimensions, is mounted transversely between the two support tables 27; the support table 29 has projecting elements 30 which can slide in guides 31 formed in the support tables 27. The support table 29 can thus slide relative to the fixed lateral support tables 27 along an axis parallel to the axis of sliding of the carriage. The sliding can be brought about by means of actuators or by hand and members are provided for locking the support table 29 in any position of its travel along its sliding axis. The upper surfaces of the support tables 27 and 29 are also perforated (the holes are not shown for simplicity) and the holes are connected to suction members so as to create suction on the support table for holding the piece to be machined on the table. As in the previous embodiment, these support tables 27 and 29 may have suitable elements for gripping the pieces as an alternative or in addition to gripping by suction:

By virtue of the support tables 27 and 29 and of the ability of the interposed table 29 to be positioned in various ways relative to the lateral tables 27, it is also possible in this variant to support and machine one or more pieces of various shapes and sizes effectively and completely in a single machining step, satisfying the conflicting requirements described in the introduction. Narrow and elongate pieces can be arranged on the lateral support tables 27 and wider pieces can be supported on the central support table 29. The pieces may also be arranged transversely so that each piece is gripped on several support tables, with the availability of an optimal support surface. A single, large piece may also be gripped on several support tables and an optimal support surface is also available in this case. By moving the movable support table 29, it is possible to perform machining operations around the piece without the machining head 15 interfering with the table 29.

Naturally, both of the carriages 18 may have the variant of Figure 6.

Clearly, further variations and/or additions to the embodiments described and illustrated may be provided. In particular, the structure of the portion of the machining centre belonging to the unit for machining the pieces may have a structure other than that shown.

With regard to the portion including the tables for supporting the pieces, these support tables may have shapes and dimensional ratios other than those illustrated; the shapes and the dimensional ratios illustrated have, however, been found very advantageous functionally. Moreover, there may be more than three support tables. In a simplified version, a single carriage with support tables may be provided; two carriages have, however, been found very advantageous functionally. The means for raising and lowering the support tables may be of any type. Other relative movements between the central support table and the lateral support tables may be provided for.

The machining head may also be capable of a further movement along an axis perpendicular to the axes X, Z and hence parallel to the axes Y_1# Y₂. The machining centre according to the present invention may advantageously be used for machining wooden workpieces, for example, for furniture production. However, its use for machining workpieces made of other materials, for example, of plastics material, is not excluded.

Claims

1. A centre (10) for machining workpieces in general, comprising at least one machining unit (15) having means (16) for machining the pieces, and also comprising means (19, 20; 27, 29) for supporting the pieces, the support means being operatively associated with the machining unit (15) , in which the machining unit

(15) is movable along two perpendicular translation axes

(X, Z) and about two rotation axes (A, B) , and in which the machining unit (15) and the support means (19, 20; 27, 29) are movable with relative motion along a third translation axis (Y.; Y₂) perpendicular to the two above- mentioned translation axes (X, Z) , characterized in that the support means (19, 20; 27, 29) comprise at least a first support table and a second support table (20; 27) which are spaced apart, and at least a third support table (19; 29) which is disposed between the first and second support tables (20; 27) and is movable relative thereto in order to vary the support configuration.

2. A machining centre according to Claim 1, in which the support tables (19, 20) can be raised and lowered relative to one another.

3. A machining centre according to Claim 2 , in which the support tables (19, 20) are elongate and rectangular in shape.

4. A machining centre according to Claim 2 or Claim 3, in which the support tables are parallel to one another and to the third translation axis (Y_x; Y₂) .

5. A machining centre according to Claim 1, in which the first and second support tables (27) are fixed, whereas the third support table (29) is movable relative to the other two.

6. A machining centre according to Claim 5 , in which the fixed support tables (27) are parallel to one another and to the third translation axis (Y_1#- Y₂) and the movable support table (29) is slidable relative to the fixed support tables (27) along an axis parallel to the third translation axis - (Y_1#- Y₂) .

7. A machining centre according to Claim 6 , in which the fixed support tables (27) are elongate and rectangular in shape .

8. A machining centre according to any one of the preceding claims, in which the third support table (19; 29) has larger dimensions than the first and second support tables (20; 27) .

9. A machining centre according to any one of the preceding claims, in which the support tables (19, 20; 27, 29) are mounted on a carriage (18) slidable along the third translation axis (Y_x; Y₂) .

10. A machining centre according to Claim 9, in which two sets of support tables are provided, each set being formed by the said first, second and third support tables (19, 20; 27, 29), and each set of support tables (19, 20; 27, 29) being mounted on a respective carriage (18) movable along a respective translation axis (Y..; Y₂) corresponding to the third translation axis, and in which the two carriages (18) are moved alternately in order to bring one or other of the two sets of support tables (19, 20; 27, 29) into the vicinity of the machining unit (15) .