Machine tool having a machine magazine and a background magazine

Abstract

In a machine tool having at least one tool spindle which is displaceable in relation to a device for holding workpieces in at least one of three spatial directions and in which the tools (W1-W7) for processing the workpieces can be chucked, there are provided a machine magazine (36) in which tools (W1-W7) provided for exchange in the tool spindle (23) are kept in store and a background magazine (31) in which tools (W1-W7) provided for exchange in the machine magazine (36) are kept in store. In the machine magazine (36), not more than four storage places (42, 43, 44, 45) for accommodating tools (W1-W7) are provided (FIG. 2).

Claims

1. A machine tool comprising: a tool spindle, a device for holding a workpiece, a machine magazine, and a background magazine, wherein said tool spindle is displaceable in at least one of three spatial directions in relation to said device for holding said workpiece, said tool spindle is adapted for exchangeably chucking tools for processing said workpiece, in said machine magazine some of said tools are provided for exchange into said tool spindle, in said background magazine others of said tools are provided for exchange into the machine magazine, only four storage places are provided in the machine magazine, each of said four storage places for accommodating one of said tools, said four storage places comprising a first, a second, a third, and a fourth storage place arranged in said machine magazine in a closed track, and said first and second storage places arranged in said closed track at a first distance with respect to one another and forming a first pair of storage places adjacent to one another along said closed track, said third and fourth storage places arranged in said closed track at said first distance with respect to one another and forming a second pair of storage places adjacent to one another along said closed track, said second and third storage places arranged in said closed track adjacent to one another along said closed track and at a second distance with respect to one another, said fourth and said first storage places arranged in said closed track adjacent to one another along said closed track and at said second distance with respect to one another, said second distance being larger than said first distance.

2. The machine according to claim 1, wherein the machine magazine is configured as a chain magazine having a chain on which said four storage places are arranged.

3. The machine tool according to claim 1, wherein said machine tool comprises a slide which is displaceable in a first spatial direction and on which a column which is displaceable in a second spatial direction is mounted, and on which column a spindle head which is displaceable in a third spatial direction is mounted, said tool spindle being rotatably mounted in said spindle head, the machine magazine being mounted on the slide.

4. The machine tool according to claim 3, wherein the machine magazine is mounted at said slide in such a manner that it is displaceable between a tool-change position, in which said tools are exchanged between the machine magazine and the tool spindle, and a tool-interchange position, in which said tools are exchanged between the background magazine and the machine magazine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention are illustrated in the drawing and are explained in more detail in the following description. In the drawing:

(2) FIG. 1 shows a schematic side view of the new machine tool;

(3) FIG. 2 shows, in a schematic plan view, the interaction of the tool spindle, the machine magazine and the background magazine for a first embodiment of the machine magazine;

(4) FIGS. 3a-3d show the method steps for the tool change and the tool interchange in the machine magazine of FIG. 2;

(5) FIG. 4 shows a second embodiment of a machine magazine, in an illustration like FIG. 2;

(6) FIGS. 5a-5e show the individual steps in the tool change and the tool interchange for the machine magazine of FIG. 4;

(7) FIG. 6 shows a third embodiment of a machine magazine, in an illustration like in FIG. 2;

(8) FIGS. 7a-7d show the individual steps for the tool change and the tool interchange in the machine magazine of FIG. 6;

(9) FIG. 8 shows a fourth embodiment of a machine magazine, in an illustration like FIG. 4; and

(10) FIG. 9 shows an embodiment for a machine tool having two tool spindles and 2 times 4 storage places, in a depiction as in FIG. 4.

DESCRIPTION OF PREFERRED EMBODIMENTS

(11) In FIG. 1, a machine tool, identified by 10, is shown very schematically in a side view. The machine tool 10 is a travelling-column machine, in which a slide 12 which is displaceable on guides 14 in the x-direction 15 is arranged on a machine frame 11.

(12) A travelling column 16 is displaced on the x-slide 12 on guides 17 which extend in the y-direction 18.

(13) A slide 19 which is displaceable in the z-direction 21, i.e. is adjustable for height, is arranged on the travelling column 16.

(14) The slide 21 carries a spindle head 22 in which at least one tool spindle 23 is mounted so as to be rotatable about a rotation axis 24 in a manner known per se. The spindle head may alternatively carry two or four tool spindles with which two or four workpieces can then be processed in a simultaneous and contour-identical manner.

(15) On its lower end, the tool spindle 23 has a typical tool holder for chucking a tool 25 with which a workpiece 26 is processed, which workpiece is retained in a device 27 which is arranged on a workpiece table 28 in the working space 29.

(16) In this manner, the machine tool 10, with the aid of a tool 25, can process the workpiece 26 in the three orthogonal spatial axes 15, 18, 21.

(17) A background magazine 31 in which numerous tools 25 can be temporarily stored is mounted separately from the machine frame 11 behind the machine tool 10.

(18) It goes without saying that it is also possible for the background magazine 31 to be fixedly connected to the machine frame 11.

(19) It should be noted, merely for the sake of good order, that the invention is also implementable with a machine tool in which the or each tool spindle 23 is not oriented in the vertical axis but in the horizontal axis, wherein furthermore not all three axes of movement 15, 18, 21 have to be implemented in the tool 25; at least one axis of movement can also be implemented in the workpiece 26, as is known, in principle, from the prior art.

(20) A transfer device 32 which is schematically illustrated and which is displaced on the background magazine along three displacement axes 33, 34, 35 which extend in an orthogonal manner in relation to one another is arranged on the background magazine 31, said transfer device 32 depositing tools into or removing them from the background magazine 31.

(21) The background magazine 31 is a rack magazine in the illustration shown.

(22) A machine magazine 36 which is arranged in an entrained manner on the x-slide 12 interacts with the background magazine 31. This machine magazine 36 is, on the one hand, displaceable in the direction indicated by a double arrow 37 such that, with its front end, it protrudes into the working space 29 and provides a tool-change position 38 for the tool spindle 23 there. The tool-change position 38 is illustrated with dashed lines in FIG. 1.

(23) In the position of the machine magazine 36 which is illustrated with solid lines, the machine magazine 36 is situated with its rear end in a tool-interchange position 39 in which, with the aid of the transfer device 32, tools 25 can be interchanged between the machine magazine 36 and the background magazine 31.

(24) In the case of the machine magazine 36 in FIG. 1, the arrangement has been chosen such that the machine magazine 36 can temporarily store three or, at most, four tools 25, i.e. has only three or four storage places.

(25) In FIG. 2, the interaction of the machine magazine 36 with the tool spindle 23, on the one hand, and the background magazine 31, on the other hand, is shown in a plan view and in a very schematic manner.

(26) The machine magazine 36 is a chain magazine having a revolving chain 41, on which four storage places 42, 43, 44 and 45 are provided.

(27) The tool spindle 23 has, in a known manner, a tool holder 46 into which and from which tools 25 can be exchanged at the tool-change position 38.

(28) In the background magazine 31, which is likewise illustrated in a schematic manner, seven storage places 47 for tools are provided, the storage places 1 to 4 being currently empty, the tools W5, W6 and W7 being in the storage places 5 to 7. The tools W1, W3 and W4 are situated in the storage places 44, 42 and 45 of the machine magazine 36, whereas the tool W2 is chucked in the tool holder 46 and has been used for processing a workpiece 26 and is now to be interchanged.

(29) It goes without saying that the storage places 47 do not necessarily have to be arranged in the background magazine 31 in the same chronological sequence in which the tools 25 are successively used; the chronological illustration in FIG. 2 has been chosen simply for the purpose of clarity.

(30) FIGS. 3a to 3d now show how the tool W2 is exchanged with tool W3 and the tool W1 is simultaneously guided back into the background magazine 31 and the tool W5 is deposited into the machine magazine 36 in its place.

(31) It can be seen in FIG. 3a that initially the tool W2 from the tool holder 46 has been deposited into the storage place 43.

(32) Thereafter, the machine magazine 31 is advanced. The storage places 42, 43, 44, 45 are indexed in the clockwise direction by one position, such that the situation in FIG. 3b results.

(33) Next, the tool W3 is now transferred into the tool holder 46, such that the situation of FIG. 3c results. Thereafter, the tool W1 is removed from the storage place 45 and transferred into the background magazine 31; see FIG. 3c.

(34) Finally, the new tool W5 from the rack magazine 31 is deposited into the storage place 44; see FIG. 3d.

(35) As a result, a similar situation is encountered in FIG. 3d as in FIG. 2, only now the tool W3 is the tool currently being employed, whereas the tool W2 is the next to be deposited in the background magazine 31 from which the tool W6 is then removed.

(36) The tool W4 is the next to be used, whereas the tool W5 is the next but one to be used.

(37) In the method for a tool change described so far, it is particularly advantageous that the machine magazine 31 is required to perform only a few indexing movements, since each tool is deposited again by the tool spindle 23 precisely from where it was removed.

(38) Furthermore, the already mentioned advantages result in that only a very small number of storage places 42, 43, 33 and 45 have to be kept available, such that both indexing of the machine magazine 36 and the movement of the y-slide 12 take place very rapidly.

(39) The method steps which have led from FIG. 2 via FIG. 3a and FIG. 3b to FIG. 3c are what are referred to as secondary time, during which processing of the workpiece is not possible.

(40) During removing of the tool W1 and inserting of the tool W5, as is shown in FIGS. 3c and 3d, the tool spindle 23 can, however, process a workpiece with the tool W3; this is what is referred to as the main time.

(41) The steps in FIGS. 3b and 3c and the steps in FIGS. 2 and 3d may also take place simultaneously, in particular the tool changes on the tool-change position 38 and on the tool-interchange position 39 are mechanically synchronized.

(42) A machine magazine 36 which likewise has four storage places 42, 43, 44 and 45 is shown in FIG. 4. Whereas adjacent storage places 42, 43, 44, 45 are equally spaced apart from one another in the chain 41 of the tool magazine 36 from FIG. 2, in the case of the tool magazine 36 from FIG. 4, two pairs of storage places 42, 43 and 44, 45 are provided, in which pairs the storage places 42 and 43 or 44 and 45 are at a smaller distance 48 from one another, while tools which are situated in different pairs and adjacent to one another in the chain 41, i.e. 43 and 44 and also 45 and 42 are at a larger distance 49 from one another.

(43) This asymmetrical arrangement of the machine magazine 36 can be implemented in particular in the case of a chain magazine, i.e. when two storage places 42; 43 or 44; 45, respectively, which are in each case adjacent to one another in the chain 41, lie very closely next to one another but are at a very much greater distance 49 from the pair 44; 45 or 42; 43, respectively, which lies diametrically opposite in the chain 41.

(44) The distance 48 then spans, for example, the minimum distance which has to be between two storage places in a chain 41, whereas the distance 49 spans the distance from the working space 29 to the background magazine 31.

(45) If, for example, the storage place 42 is now to be displaced into the position of the storage place 43, only a very short displacement path and thus an extremely rapid displacement is required, whereas very much more travel time is required in the case where the storage place 43 has to be displaced into the position of the storage place 44.

(46) Against this background, bridging of the distance 48 is utilized during the secondary time to implement extremely short tool-change times, while bridging of the distance 49 takes place during the main time, during which, therefore, the tool spindle 23 processes a workpiece using the chucked tool W2.

(47) In FIG. 4, a comparable starting position to FIG. 2 is shown, such that first the tool W2 from the tool holder 46 is deposited into the storage place 43, as can be seen in FIG. 5a. However, only one next tool W3 is temporarily stored in the chain 41.

(48) Thereafter, the machine magazine 36 indexes the chain 41 onward by the distance 48, such that the situation in FIG. 5b results, in which the empty storage place 44 is now situated in the tool-interchange position 39, as is shown by comparison with FIG. 4.

(49) The tool W3 to be used as the next tool has simultaneously been moved into the tool-change position 38, such that it can now be exchanged into the tool holder 46, as can be seen in FIG. 5c.

(50) As soon as the state according to FIG. 5c has been achieved, the tool spindle 23 can process the workpiece using the tool W3 while the tool W4 is now deposited into the storage place 44 in parallel with the main time, as can be seen in FIG. 5d.

(51) Thereafter, the tool magazine is moved again until the four corner points of the rectangle are again occupied with storage places. This situation is shown in FIG. 5e, where the empty storage place 45 is in the tool-change position 38, such that said storage place 45 can, as the next storage place, remove the tool W3 from the tool holder 46.

(52) The tool W4, which is to be employed as the next tool, is situated directly adjacent thereto, i.e. at the short distance 48. The storage place 43 having the tool W2, which is now being removed from the machine magazine 36, is situated in the tool-interchange position 39.

(53) In contrast to the machine magazine 36 of FIG. 2, not four but at most two tools are simultaneously situated in the chain 41 in the case of the machine magazine 36 of FIG. 4, which likewise contributes towards a reduction in weight and thus to a potential for more rapid displacement.

(54) Nevertheless, the tool magazine 36 of FIG. 4 requires a total of four storage places 42, 43, 44 and 45; however, a maximum of two adjacent storage places 42, 43, 44, 45 are occupied by a tool 25.

(55) Here, the secondary time lies in the steps according to FIG. 5a and FIG. 5b. On account of the short displacement path across the path 48, the secondary time is extremely short here.

(56) A further tool magazine 36 which has only three storage places 42, 43, and 44 is shown in FIG. 6 in an illustration like in FIG. 2 and FIG. 4. The machine magazine 36 is equipped, for example, with a disc 51 but may just as well be implemented in the form of a chain.

(57) Like FIGS. 2 and 4, FIG. 6 shows the relationship between the machine magazine 36 and the tool spindle 43 at the tool-change position 38 and the background magazine 31 at the tool-interchange position 39.

(58) In FIG. 7, tool changing in four steps, which progresses in a similar manner as in the case of the tool magazine of FIG. 2, is shown, except that now a maximum of always only three tools are present in the tool magazine.

(59) First, the tool W2 is inserted into the empty storage place 43, such that the situation of FIG. 7a results. Thereafter, the machine magazine 36 is rotated forward by one step, such that the situation of FIG. 7b results, in which the new tool W3 is now in the tool-change position 38, whereas the used tool W2 is situated in the tool-interchange position 39. The tool W4 is the next but one tool to be used.

(60) The tool W3 is now chucked in the tool holder 46, such that the situation of FIG. 7c results, whereupon the tool W2 is interchanged with the tool W5, as can be seen in FIG. 7d. Thereafter, the situation of FIG. 6 results, except that now the storage place 42 lies as an empty storage place in the tool-change position 38, whereas the storage place 43 lies in the tool-interchange position 39 and has already accommodated the new tool W5.

(61) Finally, it should be noted that FIGS. 2 to 7 do not show whether or not the machine magazine 36 has to be displaced in the direction of the arrow 37 of FIG. 1 between the tool change at the tool-change position 38 and the tool interchange at the tool-interchange position 39.

(62) In the event that the machine magazine 36 does not have to be displaced, a tool change at the tool-change position 38 and a tool interchange at the tool-interchange position 39 can at least in part take place simultaneously, and this can further reduce the secondary time.

(63) The machine magazine 36 from FIG. 4 may also be arranged such that the storage places 42, 43 and 44, 45, which are arranged spaced apart from one another at the small distance 48, do not lie in the deflection corners of the chain 41 but in between, i.e. as shown in FIG. 8.

(64) In the starting position of FIG. 8, the tool spindle 23 having the last used tool W2 is situated in the tool-change position 38 and the machine magazine 36 having the already previously exchanged tool W1 is in the tool-interchange position 39.

(65) In a first step, the tools W2 and W4 are now simultaneously deposited into the storage places 43 and 45 of the machine magazine 36. Thereafter, the machine magazine 36 is displaced by the distance 48, such that the storage places 42 and 44 are now situated in the tool-change position 38 or the tool-interchange position 39, respectively.

(66) Then, simultaneously, the tool W3 is transferred into the tool spindle 23 and the tool W1 into the storage place, which was previously occupied by the tool W4 and is now empty, in the background magazine 31.

(67) The main time now starts, during which the tool spindle 23 processes a workpiece using the tool W3. The background magazine 31 simultaneously displaces the tool W5 into the tool-interchange position 39.

(68) When the tool spindle 23 now approaches the tool-change position 38 again, the machine tool is situated in the displacement situation according to FIG. 8 again.

(69) In the event that the machine tool is equipped with two tool spindles 23, 23, consequently 2 times 4 storage places are provided in the machine magazine 36, as shown in FIG. 9.

(70) Apart from the fact that always two tools are changed both on the tool spindles 23, 23 and on the background magazine 31, the tool-change methods which can be carried out with multiple-spindle machines do not differ from the method described above.

(71) The storage places 43, 42, 43 and 42 and the storage places 44, 45, 44 and 45 each form a group and are spaced apart from one another in the respective group at the same distance, which distance corresponds to half the distance between the tool spindles 23, 23.