DE29821047U1 - Machine tool arrangement with a device for an automatic tool change - Google Patents

Description

Machine tool arrangement with a device for automatic tool changing

The invention relates to a machine tool arrangement with at least one machine tool and with at least one device for an automatic tool change, essentially consisting of at least one shelf, magazine or the like accommodating the individual tools to be changed and at least one tool changer.

Such machine tool arrangements are known in many different forms and are used primarily in CNC-controlled machine tools.

It is known to provide chain magazines to accommodate the tools to be exchanged and replaced, which are usually attached to the mobile stand of the machine tool, which is designed as a drilling machine or a lathe or milling machine. Due to the limited space available, such chain change magazines can usually only accommodate around sixty change positions and thus sixty tools, and in very large drilling machines up to ninety positions for ninety tools. Such a chain magazine is described, for example, in EP-B-O 011 710. To change a tool

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The chain magazine is moved to a defined location and adjusted. An additional tilting device for a horizontal or vertical position allows the tool to be transferred. In addition to the limited number of interchangeable tools, this arrangement also results in a high level of mechanical effort for the chain magazine, which is designed as a chain conveyor, each with a clamping device for securing the tools that are not being used. In addition, due to this arrangement, the tools can only be inserted into a horizontally arranged machining spindle.

EP-B-O 297 034 discloses a changing device for a machine tool with a magazine for removing a tool or workpiece, which magazine can only hold a relatively small number of tools and is not static, but rather mobile, namely rotatable about a vertical axis, so that the respective tool can be brought into the area of the manipulator. The respective tool must be changed in a vertical spindle position of the machine tool.

DE-A-195 10 498 discloses a tool changing device for machine tools with several parts storage units that hold the individual tools and rotate around their vertical axis

^, which means increased mechanical manufacturing, assembly, automation and operating costs. Due to a horizontally guided gripper head, each tool must be secured in the parts storage by an additional clamping mechanism due to its horizontal position in the parts storage. The tool changing mechanism is only suitable for a work spindle in a horizontal position. A stand 0 with the tool changer must be able to move along the parts storage, which requires a correspondingly large amount of space.

DE-A-34 40 762 discloses a vertically operating machine tool with handling device, which can only be adjusted on a circular path in one plane. The

Changeover options, whereby the handling device is primarily used to change the workpieces and not the tools.

A three-axis articulated arm has been known for even longer as a tool changer from DE-A-23 54 446, but it can only move in one plane and can therefore only change a very limited number of tools.

DE-A-36 17 981 discloses a device for holding and/or positioning workpieces and/or tools or the like

with a four-axis rotating and articulated arm, which in turn can only move in a plane parallel to the axis of rotation and thus cannot reach any point in space. The workpiece holder in particular is mounted on a support frame so that it can rotate around an upright axis and can be changed in position within a plane extending approximately parallel to the axis of rotation, which means a high level of mechanical effort, although the number of interchangeable tools is still limited.

DE-C-34 40 604 describes an automatic tool changing device for machine tools, in particular for universal machining centers, with a three-part articulated arm manipulator ^, whereby a three-axis or four-axis positioning control is provided. This results in a relatively limited number of tools with a relatively high level of mechanical effort.

Despite these various efforts and attempts at solutions, machine tool arrangements of the type mentioned at the beginning have so far only provided limited space for storing tools to be changed, which is also limited by the range of the respective tool changers. A further disadvantage is generally present in the previously known solutions in that the spindle head of the machine tool, despite its ability to pivot for different machining operations, the

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i.e. an orthogonal spatial position of the tool is permitted, in such an arbitrary position no tool change is permitted, but it requires its return to a defined starting position, usually a vertical or horizontal orientation of the tool axis.

The invention is therefore based on the object of creating a machine tool arrangement of the type defined at the outset, in which a considerably higher or almost any number of tools can be kept ready for changing and it should also be possible to change the tools in an orthogonal

P Spatial position, i.e. deviating from a horizontal or vertical position, of the tool holder spindle and thus reducing the time required for tool changes.

This object is achieved according to the invention in that the tool magazine(s) or tool holder rack(s) is/are stationary and/or static or immobile during use and has/have plug-in receptacles for the tools in which the tools are held by gravity, that the tool changer is a robot with at least six axes or six degrees of freedom and that this robot serving as a tool changer has a predetermined fixed position or

" has a predetermined constant trajectory.

This allows the use of very simply designed tool magazines of almost any size, so that a corresponding number of tools can be kept ready. The tool changer in the form of a robot with at least six axes or six degrees of freedom allows programming that allows every tool to be detected at every location and exchanged for the previous tool on the machine tool. Since the tools in the magazine(s) can be held exclusively by gravity, complex clamping devices for securing them or conveying aids on the magazines can be avoided. In addition,

When changing tools, unlike with chain magazines, numerous unused tools do not have to be moved if only one is to be replaced.

Above all, however, the robot serving as a tool changer according to the invention with at least six degrees of freedom, when appropriately programmed and coupled with the programming of the control of the machine tool, allows the tools to be changed even when the tool spindle is oriented anywhere in space, so that the time and movement required to adjust the tool spindle to a defined, predetermined position with each tool change can be avoided and saved.

For particularly simple programming of the robot serving as a tool changer and thus for simple and effective handling of the entire arrangement, it is expedient if the plug-in receptacles for the tools to be changed in the respective magazine or shelf are arranged in at least one common plane or in several, possibly also differently inclined, planes and if this plane(s) and the position of this plane(s) are programmed into the control and programming of the robot(s) - for example by moving to three points on the plane, i.e. by so-called teaching - whereby the distances between the plug-in receptacles in the respective plane and their mutual spatial arrangement are programmed in particular as an offset. Thus, every tool location is known to the programming and control of the tool changer, so that the tool change can take place automatically according to a corresponding program, as may be required, for example, by a specific production on the machine tool or a corresponding center with this machine tool or several machine tools.

It is particularly advantageous and advantageous for simple programming if the spatial allocation of the plug-in receptacles is a 5 simple geometric pattern, whereby the plug-in receptacles

for example, they can be arranged next to each other on straight lines or circular arcs and/or with the same distances or whole-number multiples or fractions of these distances. A certain regularity of the spatial arrangement of the plug-in receptacles can therefore be specified, which simplifies programming.

It is particularly advantageous if the plug-in receptacles are arranged on circular arcs or straight segments in straight rows, each of which is arranged centrally to a common central axis, and if this central axis is aligned with the

™ vertical axis of rotation "1" of the robot in particular.

In particular, with plug-in receptacles arranged on circular arcs, the robot practically always has the same distance to the tools on these circular arcs, which in turn simplifies programming and the tool change process. With straight rows of plug-in receptacles, such "straight lines" can be arranged like secants on a circle around the robot's central axis, which can also be easily taken into account in the robot's program.

At the same time, this arrangement allows the robot’s range with its six axes or degrees of freedom to be used as effectively as possible.

A further embodiment of the invention can consist in providing at least one robot with seven axes or seven degrees of freedom as a tool changer, the seventh axis being a predetermined path, for example in the form of a straight line, a curved path and/or a circular path, on which the robot can move with six axes or degrees of freedom. This allows the range of this tool changer to be further increased, so that a tool magazine of the appropriate size with a practically unlimited number of tools could also be used. This also makes it possible to carry out a tool change on at least one other machine tool with the same robot if

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it can be moved along its path from one machine tool to another. This can increase the effectiveness and profitability of the arrangement.

The robot can have its own drive motor for moving or moving along its seventh axis or its seventh degree of freedom. This movement of the robot can also be controlled by its programming, so that it can operate another machine tool arranged in the area of its seventh axis or its seventh degree of freedom in the sense of a tool change in such a way that unnecessary waiting times or breaks do not have to occur at any of these machine tools.

It is particularly advantageous if the robot is an articulated arm robot with at least one articulated arm. Such robots with corresponding degrees of freedom can even be purchased as commercially available parts, so that the implementation of the arrangement according to the invention with this tool changer can be made particularly simple and inexpensive and the adaptation is carried out primarily by the corresponding programming.

This results in further advantageous design options ^ in connection with machine tools:

5 The robot can be programmed to precisely direct cooling water nozzles or the cooling water jet on the machine tool. This means that it can also adapt the direction of the cooling water flow to the changed tool, particularly after a tool change.

The robot can also be programmed to blow out drill holes or similar, for example before thread cutting with a machine tool. Before replacing the drill with the thread cutter, the drill hole can be cleaned using a corresponding program with the help of the tool changer, so that this does not have to be done by an operator.

must.

Since the tools are occasionally reground during their use and their dimensions are thereby changed, a further embodiment of the invention can consist in that the arrangement has at least one measuring probe with which the robot(s) can check an interchangeable tool of the machine tool and in particular its length, and that the measuring probe is connected to the control of the machine tool and/or the programming of the robot, so that, for example, the

- Grinding means that the changed tool length is taken into account by the machine and/or robot control system the next time it is used. Likewise, a worn tool can be exchanged for a new tool in this way and its length can then be taken into account by the control system.

It should also be mentioned that the use of a robot with a seventh axis can also be useful for machine tools with long slides or for long boring machines in order to be able to carry out the tool change 0 at any position of the tool spindle, even at a position at a greater distance from the tool magazine.

k Overall, especially when combining one or more of the features and measures described above, it is possible to change tools of any size and type on lathes, milling machines or drilling machines fully automatically, whereby the spindle head position currently in use does not have to be returned to a specific basic position, particularly in the case of an orthogonal spatial position. The tools can be located in a static, i.e. not self-rotating or movable, stationary tool magazine without moving parts, whereby, for example, there can be four hundred slots and the tools are stored in them only by gravity without additional clamps. Since the tools are held by plug-in holders, they can be stored in a space-saving manner in the tightest of spaces on one or any level within reach of the six-axis robot.

The tool magazines can have a wide variety of shapes, as long as they are within reach of the robot. If the robot has a seventh axis, i.e. is movable, even more tool storage locations can be provided and included. The otherwise usual dual storage such as a tool storage cabinet on the one hand and a tool change magazine on the other is therefore no longer necessary. Furthermore, the respective tool slot of the processing machine can be equated with the software tool table location.

Another advantage is the quick changeover time which

™ This is made possible, among other things, by the fact that the CNC machine control can transmit the respective angular position of the spindle head to the robot control, so that the robot can then change the tool in this position.

For a quick tool change, it is useful if the robot has at least two grippers on its articulated arm - in the case of a robot with several articulated arms on each articulated arm. This means that a new tool can be picked up in the magazine and moved to the area of the spindle head of the machine tool, then the previously used tool can be removed there with the second gripper.

^ Tool must be removed and the new tool inserted.

Exemplary embodiments of the invention are described in more detail below with reference to the drawing. It shows in a schematic and perspective representation:

0 Fig.1 a machine tool arrangement with a machine tool

and a tool changer designed as a robot with six axes or six degrees of freedom as well as a circularly arranged tool rack or magazine, whereby the articulated arm of the robot and its attached

5 Both grippers are in the area of the tool magazine

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condition,

Fig.2 a view of the arrangement shown in Fig.l

a slightly different perspective, with the robot's grippers in the area of the tool holder or the

spindle head of the machine tool,

Fig.3 is a plan view of the arrangement according to Fig.1, from which the circular arrangement of the tool magazine and the arrangement of the vertical axis of rotation 1 of the

Robot in the center of curvature of this circular arc

^ is clearly visible,

Fig. 4 shows a modified embodiment in which a machine tool with a very long carriage and accordingly a robot with a seventh degree of freedom is provided as a tool changer, the seventh degree of freedom being designed as a linear displacement of the robot along the machine bed of the machine tool,

Fig.5 shows a modified embodiment in which ^ a robot with a seventh

Degree of freedom i.e. a linear displacement

5 is provided, in whose sliding area two

machine tools are arranged so that one tool changer can serve two machine tools and

Fig. 6 in enlarged scale a probe for measuring the length

0 of each tool, whereby the two grippers

of the robot and a tool gripped by one of these grippers are shown in the position of use, as is also the case in Figures 1 to 4 for the sake of clarity.
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In the following description of several embodiments, parts that have the same function are given the same reference numbers, even if their shape is slightly modified.

Figures 1 to 5 show machine tool arrangements, where the arrangements according to Figures 1 to 4 each show one machine tool 1, whereas Figure 5 shows an arrangement with two machine tools 1.

In all embodiments, a device for

. an automatic tool change is provided, which essentially consists of at least one shelf, magazine 3 or the like that holds the individual tools 2 to be changed and a tool changer 4, which will be described in more detail later and which transports the individual tools 2 from the magazine 3 to the spindle head 5 of the machine tool 1 and vice versa.

The tool magazine(s) 3, which in the embodiments have the form of shelves, are stationary and static in the sense that they do not have any moving parts, i.e. no pivoting, tilting or rotating tool holders

Rather, they only have sockets 6 in which ^ the tools 2 are held exclusively by gravity.

Thus, these magazines 4 are structurally simple and the insertion and removal of the tools 2 does not require any additional measures such as pivoting or opening of retaining clamps or the like.

The tool changer 4 already mentioned is a robot with at least six axes or six degrees of freedom, which is therefore also referred to as "robot 4" below. This robot 4, which serves as a tool changer, has a predetermined fixed position in relation to the magazine 3 or shelf in the embodiment according to Fig. 1 to 3 or a predetermined constant movement path in the embodiment according to Fig. 4 and 5, so that a simple

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Programming for tool changing is possible.

The figures indicate that the spindle head 5 and the spindle located thereon for holding the respective tool 2 do not necessarily require a vertical or horizontal or other defined position for the tool change. Rather, it is possible that the control and programming of the robot 4 is coupled with the control and programming of the machine tool 1 in such a way that a tool 2 located on the machine tool 1 in any spatial orientation can be moved without resetting the

^. spindle head 5 can be exchanged into a starting position.

This is made possible by the fact that the robot 4 has at least six axes or six degrees of freedom.

In all embodiments it is indicated that the plug-in receptacles 6 for the tools 2 in the magazine 3 or shelf can be arranged in at least one common level or in several levels one above the other. These levels and the position of these levels can be programmed into the control and programming of the robot 4, whereby this can also be done, for example, only after the assembly of the entire arrangement by moving to three points on the respective level, i.e. by so-called teaching.

&agr; The distances between the plug-in receptacles in the respective plane and their mutual spatial arrangement can be programmed as offset 5.

In the exemplary embodiments, the spatial arrangement of the plug-in receptacles 6 is a simple geometric pattern in which the plug-in receptacles lie next to one another on circular arcs, with a lower level showing three concentric circular arcs of this kind, while the levels above each have only one circular arc of this kind with plug-in receptacles lying next to one another. In this case, the plug-in receptacles can be spaced at the same distance along the course of these circular arcs, but these distances can also be different in the different levels in order to

to take into account the different sizes of tools 2. In Figures 1 to 3, it can be seen that in this embodiment, the central axis around which the plug-in receptacles 6 are arranged on circular arcs corresponds to the vertical axis of rotation "one" of the robot, so that all plug-in receptacles 6 located on a common circular arc can be reached with the same articulated arm position of the robot and it only has to be rotated about its vertical axis. The plug-in receptacles 6 located on a parallel circular arc can then be reached by a corresponding extension or greater or lesser bending of the articulated arm of the robot 4. The arrangement of the plug-in receptacles

W 6 on circular arcs or other simple geometric figures makes tool changing and programming of the controls easier and faster.

In the embodiments according to Fig. 4 and 5, a robot 4 with seven axes or degrees of freedom is provided as a tool changer, whereby the seventh axis or the seventh degree of freedom is a predetermined path in the form of a straight or linear 0 rail guide 7, on which the robot 4 can be moved with six axes. Thus, practically the same robot is provided as in the embodiment according to Figs. 1 to 3, but is mounted so that it can move, rather than being stationary.

As a result, the robot 4 can be used if, according to Fig. 4, a machine tool 1 with a very long machine bed 1a is part of the arrangement or if, according to the embodiment according to Fig. 5, another machine tool 1 is arranged in the area of the seventh axis or the seventh degree of freedom of the robot 4. In Fig. 5 it can be seen that the rail guide 7 is arranged between the front sides of the two machine tools 1. However, it could also be provided to the side of it in order to be able to operate correspondingly long machine tools 1. In addition, the rail guide 7 could also be arranged next to the machine tools 15 in order to be able to operate on both sides of such a rail guide.

to be able to operate the machine tools 1 located there. In this case, the robot 4 has its own drive motor (not shown in detail) for moving or moving in the sense of its seventh axis or its seventh degree of freedom in the exemplary embodiment, which can then be controlled by the programming and control of the robot 4.

In all embodiments, the robot 4 is an articulated arm robot with at least one articulated arm 4a, which can therefore change the distance of its two grippers 8 from its central vertical axis of rotation by bending it more or less strongly. The robot 4 has

^^ namely on its articulated arm 4a in the embodiment two grippers 8, which can be seen particularly well in Fig.6, but also partly in the other figures, so that the changing of a tool 2 can be accelerated. For example, a new tool can be transported to the spindle head 5 of the machine tool 1, then the previous tool 2 can be removed from the spindle head 5 with the second gripper and the new tool can be inserted again, after which the removed tool 2 is transported back to the magazine 3.

In the already mentioned Fig.6, a measuring probe 9 is shown with which the robot 4 can check an interchangeable tool 2 of the machine tool 1 and in particular its length, whereby this measuring probe 9 is also indicated in Figures 1 to 5 and is of course within reach of the articulated arm 4a and the gripper 8. Fig.6 shows these two grippers 8 of the robot 4, whereby one of the grippers holds a tool 2 and places it on the measuring probe 9. This is also indicated in the same way in Figures 1 to 4, although there the articulated arm of the robot 4 is active in a different position. The tool 2 and the grippers 8 therefore do not belong to the probe 9, but work together with it if necessary.

The measuring probe 9 is connected to the control of the machine tool 1 and/or

the control or programming of the robot 4, so that the tool length changed, for example after grinding, is recognized and taken into account by the machine and/or robot control the next time this tool 2 is used.
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Since a commercially available six-axis robot can be used as a tool changer and can be easily adapted to the specific application as a tool changer through its programming and the attachment of two grippers 8, the overall result is an inexpensive arrangement that enables quick and easy tool changing in any position of the spindle head.

^ 5 enabled.

The automatic tool change on at least one machine tool 1 can be carried out with a robot serving as a tool changer 4 with at least six axes or degrees of freedom, whereby the programming of the control of this robot 4 allows adaptation to the stationary tool magazine 3 and the machine control, so that the tool change can be carried out quickly and precisely at any 0 position of the tool 2 in the machine tool 1.

Expectations

Claims (13)

Expectations 1. Machine tool arrangement with at least one machine tool (1) and with at least one device for an automatic tool change, essentially consisting of at least one shelf, magazine (3) or the like accommodating the individual tools (2) to be changed and at least one tool changer (4), characterized in that the tool magazine(s) (3) or tool receiving shelves _ is/are stationary and/or static during use and plug-in has/have holders (6) for the tools (2) in which the tools (2) are held by gravity, that the tool changer (4) is a robot with at least six axes or six degrees of freedom and that this robot (4) serving as a tool changer has a predetermined fixed position or a predetermined constant movement path in relation to the magazine(s) (3) or shelf(s). 2. Arrangement according to claim 1, characterized in that the control and programming of the robot (4) is coupled with the control and programming of the machine tool (1) in such a way ^ is that a tool (2) located on the machine tool (1) in any spatial orientation can be exchanged without being returned to an initial position. 3. Arrangement according to claim 1 or 2, characterized in that the plug-in receptacles (6) for the tools (2) in the magazine (3) or shelf are arranged in at least one common level or in several levels, possibly with different inclinations, and that these levels and the position of these levels are included in the control and programming of the robot(s) (4) - for example by approaching three points of the plane, i.e. by so-called teaching - is programmed, 5 whereby the distances between the plug-in receptacles (6) in the respective »ti ··· Level and their mutual spatial arrangement is programmed in particular as an offset. 4. Arrangement according to one of claims 1 to 3, characterized in that the spatial arrangement of the plug-in receptacles (6) is a simple geometric pattern, whereby the plug-in receptacles (6) are arranged, for example, on straight lines or circular arcs next to one another and/or at matching distances or whole-number multiples or fractions of these distances from one another. ^ 5. Arrangement according to claim 4, characterized in that the plug-in receptacles (6) are arranged on circular arcs or straight-line segments, each of which is arranged centrally to a common central axis, and that this central axis coincides with the vertical axis of rotation "one" of the robot in particular. 6. Arrangement according to one of claims 1 to 5, characterized in 0 is characterized in that at least one robot (4) with seven axes or seven degrees of freedom is provided as a tool changer, the seventh axis having a predetermined path, for example ^ in the form of a straight line, a curved path and/or a circular path on which the robot (4) can move with six axes or degrees of freedom. 7. Device according to claim 6, characterized in that the robot (4) has its own drive motor for displacement or movement in the sense of its seventh axis or its seventh degree of freedom. 8. Arrangement according to one of claims 1 to 7, characterized in that at least one further machine tool (1) is arranged in the region of the seventh axis or the seventh degree of freedom of the robot (4). ft · ·
· < 9. Arrangement according to one of claims 1 to 8, characterized in that the robot (4) is an articulated arm robot with at least one articulated arm (4a). 10. Arrangement according to one of claims 1 to 9, characterized in that the robot is programmed for the targeted alignment of cooling water nozzles or the cooling water jet on the machine tool. 11. Arrangement according to one of claims 1 to 10, characterized in that the robot (4) is programmed for the targeted blowing out of drill holes, for example before thread cutting with a machine tool. 12. Arrangement according to one of claims 1 to 11, characterized in that it has at least one measuring probe (9) with which the robot(s) (4) can check an exchangeable tool (2) of the machine tool (1) and in particular its length, and that the measuring probe (9) is connected to the control 0 of the machine tool (1) and/or the programming of the robot (4), so that, for example, the tool length changed after grinding is taken into account by the machine and/or robot control during the next use. * is taken into account. 13. Arrangement according to one of the preceding claims, characterized in that the robot (4) has at least two grippers (8) on its or each articulated arm (4a). Patentarf