DE102016119565B4 - Tool changer, machine tool and method for tool changing - Google Patents

Abstract

Machine tool (10)
with at least one work spindle (16) which has a tool holder mount (19),
with a tool magazine (12) designed to hold several tool holders (22), and
with a tool changer (27) with at least one gripper (29) having a first gripper contour (35) for a first tool holder (22) and a second gripper contour (36) for a second tool holder (42), wherein the gripper contours (35, 36) are assigned to different tool holders with different gripper disc diameters,
wherein the tool changer (27) is associated with an angled head (47) which has a receiving contour (24) matching the first gripper contour (35), and
wherein the work spindle (16) is movable about a tilting axis (18) in order to orient a tool (13 - 15) held in the angle head (47) parallel to the pivoting axis (30) of the tool changer (27) by pivoting the work spindle (16) about the tilting axis (18).

Description

The invention relates to a machine tool, in particular a machining center, and a method for changing tools on a machine tool.

From the DE 10 2014 226 969 A1 A tool changer for a machine tool is known that is capable of inserting tools carried by a tool holder into a work spindle or, alternatively, into an angled head mounted on the work spindle. For this purpose, the tool holders or tools to be inserted into the angled head are held by an adapter. This adapter has a connection at one end that fits the tool changer and the tool magazine, and at its other end, set at an angle to this connection, a receptacle for the tool or tool holder to be inserted into the angled head. After the tool change, the adapter initially remains on the tool changer and is then returned to the tool magazine. The tools to be inserted into the angled head are held by a tool holder whose dimensions are smaller than those of the other tool holders that are inserted directly into the work spindle. The elongated angled adapter thus also serves as an adapter for handling tool holders with different clamping shank diameters in one and the same machine tool.

Furthermore, from the WO 2015/036428 A1 A machine tool with a tool-changing gripper is known, which has a large and a small gripper contour. The tool gripper has two gripper fingers, which are contoured on their facing sides to receive the gripping disc of a tool holder. The contours of the small and large gripping discs overlap, so that the gripper can grasp and transport both tool holders with large and tool holders with small gripping discs.

The use of angled intermediate adapters allows the insertion of tool holders with a smaller diameter into angled heads and thus represents a special solution.

The object of the invention is to provide a concept with which the flexibility of a machine tool, in particular a machining center, can be increased also with regard to the use of different tool holders.

This problem is solved with the machine tool according to claim 1 as well as the method according to claim 11:

The tool changer according to the invention comprises at least one gripper, which has a first gripper contour for a first tool holder and a second gripper contour for a second tool holder. The gripper contours are assigned to different tool holders with different gripper disc diameters. This allows the gripper to transport at least two tool holders of different sizes from the tool magazine to the work spindle (and/or an attachment driven by it, for example, an angle head) and back, as required. The gripper can thus be considered a "two-size gripper" or a "two-type gripper".

The gripper can be used on machine tools with one or more work spindles that have the same or different toolholder mounts and that may be equipped with turret heads, angle heads, or other attachments, or in similar situations. The tool changer according to the invention can, in particular, also work with tool magazines that hold different toolholders and/or have different toolholder mounts. Alternatively, adapters can be provided in the tool magazine that have uniform dimensions on the magazine side or loading portal side and a mount for a smaller toolholder (e.g., with a smaller nominal diameter) on the tool side. This allows conventional machine tools or machining centers to be used more flexibly than before with the novel tool changer and, if necessary, with the addition of appropriate adapters for the tool magazine.

Preferably, the gripper is pivotably arranged about a gripper axis, similar to a conventional tool changer, but the two alternatively usable gripper contours are arranged one behind the other, viewed from the gripper axis. Preferably, the gripper contours define contour centers that are located on a radial to the gripper axis. This results in a simple gripper design that also allows the changing of different-sized tool holders to be easily integrated into the tool change process.

The gripper is particularly compact when its two contours define circular shapes that overlap. In other words, the distance between the centers of the two circles is less than the sum of their radii. Preferably, however, this distance is at least slightly larger than the diameter of the larger gripper contour. This achieves both a compact design and reliable gripping performance. The size of the gripper contour is determined by its diameter. The diameter of the gripper contour, in turn, corresponds to the diameter of the gripper disc of a tool holder (or tool).

The gripper preferably has two fingers whose opposing sides define the gripper contour. At least one of the two fingers, preferably both, are movably mounted to move towards and away from each other and are preferably spring-loaded against each other. The two fingers can pivot slightly closer together than the diameter of the gripper contour would otherwise dictate. The diameter of the gripper contour is defined for the working position of the fingers, in which they securely grip a gripping disc of a tool holder between them.

In a preferred embodiment, the tool changer includes an adapter having an adapter contour that corresponds to a tool holder, at least with respect to the surfaces relevant to the tool changer and a tool magazine. The adapter is configured to interact with one of the gripper contours, preferably the larger of the gripper contours. Furthermore, the tool changer preferably has a tool receptacle that can accommodate a smaller tool holder that fits the smaller of the gripper contours of the tool changer.

The tool holder is preferably arranged concentrically to the adapter contour and oriented in the same way. For example, the adapter contour can be formed by an opening in the adapter, arranged such that the gripping disc of the tool holder located in the adapter is directly adjacent to the gripping disc of the adapter. Such an adapter can be arranged in the tool magazine and accommodate tools or tool holders of a smaller design. Preferably, the adapter is magazine-resident, i.e., it does not leave the magazine, including any gantry loader belonging to the magazine, during tool changes. In particular, it is not picked up by the tool changer. The tool changer removes the appropriate tool or tool holder (of a smaller design) from the magazine or the gantry loader and leaves the adapter in the gantry loader or magazine. From the perspective of the tool changer and the machine tool, the tool magazine (including any gantry loader) then presents both larger and smaller tool holders. This increases the versatility of the machine tool. In a preferred embodiment, the tool changer has a pivot arm rotatable about a pivot axis, which carries a gripper at each of its opposite radial ends. This arrangement can be referred to as a double gripper.

The machine tool and/or tool magazine may also include spindle attachments, such as an angle head, a turret head, or spindle extensions. The tool changer can then insert large tool holders into the work spindle or, alternatively, insert tools of either large or small design into the respective spindle attachment, particularly the angle head. This is especially easy to implement if the work spindle can swivel around an axis by the angle defined by the angle head, so that the axis of rotation of the angle head's mounting for the tool holder can be oriented parallel to the rotation and stroke axis of the tool changer. The gripper with two gripper contours offers the advantage, particularly in combination with angle heads or other spindle attachments, that the number of angle heads or attachments required does not have to match the number of tool holders. In particular, for a large number of tools (held in corresponding tool holders), only a small number (e.g., just one) of angle heads need to be kept on hand. This offers particular advantages for machining operations with high tool wear. Loading the machine tool and tool magazine can be carried out with less effort compared to conventional solutions.

• 1 eine erfindungsgemäße Werkzeugmaschine mit erfindungsgemäßem Werkzeuggreifer, in schematisierter Darstellung,
• 2 den Werkzeugwechsler der Werkzeugmaschine nach 1, in schematisierter Ansicht,
• 3 das Werkzeugmagazin der Werkzeugmaschine nach 1, in schematisierter beispielhafter Darstellung,
• 4 einen Werkzeughalter mit Adapter für die Werkzeugmaschine und/oder das Werkzeugmagazin nach 3, in schematisierter Darstellung,
• 5 einen an der Arbeitsspindel gehaltenen Winkelkopf mit Werkzeug in Arbeitsstellung, in schematisierter Seitenansicht, und
• 6 die Arbeitsspindel und den Winkelkopf nach 5 in Werkzeugwechselstellung, in schematisierter Seitenansicht.

Further details of advantageous embodiments of the invention are the subject of the drawing, the description, or the claims. They show:

• 1 a machine tool according to the invention with a tool gripper according to the invention, in schematic representation,
• 2 the tool changer of the machine tool 1 , in a schematic view,
• 3 the tool magazine of the machine tool after 1 , in a schematic, exemplary representation,
• 4 a tool holder with adapter for the machine tool and/or the tool magazine 3 , in schematic representation,
• 5 an angled head with tool in working position, held on the work spindle, in a schematic side view, and
• 6 the work spindle and the angle head 5 in tool-changing position, in schematic side view.

In 1 Figure 10 schematically illustrates a machine tool 10, which is linked to a tool magazine 12 via a tool changing device 11. The tool magazine serves to hold several tools 13, 14, 15 (and others) that can be transferred into and out of a work spindle 16 of the machine tool 10 using the tool changing device 11. The machine tool 10 has at least this one work spindle 16 and, optionally, several such work spindles.

The work spindle 16 is preferably guided in a movable manner. For this purpose, it can, for example, be guided as in 1 The work spindle 16 is shown to be movable in the vertical direction (Y-direction) as well as in the horizontal direction perpendicular to it (X-direction). The work spindle 16 itself is rotatably mounted about a drive axis 17, which is oriented perpendicular to the X-axis. A workpiece (not shown in further detail) can be moved towards and away from the work spindle 16 by means of a corresponding workpiece slide. This slide can also provide further movement options such as rotation or tilting.

In a preferred embodiment, the working spindle 16 can also be movable about a preferably horizontal tilting axis 18.

The work spindle 16 is provided at its end facing the work area with a tool holder mount 19, which is equipped with a standard clamping device, for example for hollow taper shanks or for steep taper shanks or the like.

For further illustration, see below. 3 Reference is made to Figure 1. This schematically illustrates the tool magazine 12, in which tools 13, 14, 15, and further tools 20, 21 are shown. Each of these tools 13 to 15, as well as 20, 21, is supported by a tool holder 22, which has, for example, a frustoconical or hollow frustoconical body 23 that transitions into a gripping disc 24. These conical or hollow conical bodies 23 of all tool holders 22 are identical. Likewise, the gripping discs 24 are identical. Thus, the tool holders 22 can be picked up from the individual storage positions in the tool magazine 12 by a gantry loader system 25 and fed to the tool changing device 11, or removed by the tool changing device 11 and fed to the storage positions. The gantry loader is movable in several directions X, Y, Z and, if necessary, can also be rotated or pivoted about an axis, for example, a vertical axis, as shown in Figure 1. 3 as indicated by an arrow 26.

The tool magazine 12 of this design and the associated portal loader 25 serve only for illustrative purposes. It should be noted that the tool changing device 11 can also cooperate with other tool magazines 12.

The tool changing device 11 comprises a tool changer 27 with a swivel arm 28, which includes at least one, but preferably two or more grippers 29. The gripper 29 is in 2 The pivot arm 28, which is rotatably mounted about a preferably horizontal gripper axis 30 parallel to the Z-direction by at least 180°, carries the gripper 29 at its radially outer end, which has two gripper fingers 31, 32. At least one of these two fingers 31, 32, preferably both, are pivotably mounted on the pivot arm 28 about pivot centers 33, 34 and are biased towards each other by a spring means not further illustrated.

The gripper fingers 31, 32 have a shape on their facing sides such that they define a first gripper contour 35 and a second gripper contour 36 in pairs. The two gripper contours 35, 36 each lie on in 2 The circles 37 and 38, illustrated with dashed lines, correspond to the diameters of gripper discs of different sizes. The gripper contours 35 and 36 are preferably arranged such that the larger gripper contour 35 is located radially outside the gripper axis 30, and the smaller gripper contour 36 is located radially further inside. Preferably, the two centers 39 and 40 defined by the circles 37 and 38 are arranged on a line 41 oriented radially to the gripper axis 30. The gripper axis 30 intersects the line 41.

In a relaxed state, i.e., without a gripping disc 24 held between the fingers 31, 32, the fingers 31, 32 can be removed from the 2 The illustrated work positions should be positioned slightly further apart. The position after 2 corresponds to the position of fingers 31, 32 when the tool holder is gripped.

The gripper contours 35, 36 are arranged to overlap. This means that the circles 37, 38 cover a common area, or, in other words, the distance between the centers 39, 40 is less than the sum of the radii of the two circles 37, 38. Preferably, however, the distance is not less than The radius of the larger circle 37 is, in any case, not less than the radius of the smaller circle 38. In this way, both large and small gripping discs corresponding to the diameters of circles 37 and 38 are alternatively fixed and securely held in the gripper 29. In a preferred embodiment, the pivot arm 28 includes two grippers 29 which are arranged offset from each other by 180° with respect to the pivot axis 30 (as in 1 (shown). This so-called double gripper with grippers 29 arranged at opposite radial ends of the swivel arm 28 is very narrow and can be folded into a position opposite the illustration when not in use. 1 It can be swivelled into a 90° rotated position. This allows the overall width of a machine tool to be kept small.

The system illustrated in this respect also includes a tool holder 22 according to 4 , which forms an adapter 22-1 for receiving a smaller tool holder 42. The tool holder 42 has a conical, i.e., frustoconical or hollow frustoconical body 43, which is smaller than the hollow body 23 of the adapter 22-1. Furthermore, the tool holder 42 has a gripping disc 44, the diameter of which is smaller than the diameter of the gripping disc 24. Both gripping discs 24, 44 each have a gripping groove on their outer circumference, the diameter of which corresponds to the diameter of circle 37 (gripper groove of gripping disc 24) or to the diameter of circle 38 (gripper groove of gripping disc 44).

The adapter 22-1 to 4 forms an adapter with a tool holder mount for the tool holder 42. The tool holder mount includes a [unclear text - likely a component or element]. 4 The dashed line illustrates the seat 45, which is formed by a recess adapted to the body 43. The adapter 22-1, in particular the body 23, is attached to its 4 left end face preferably open, so that holding or clamping means can reach a clamping contour 46 formed in the body 43.

The machine tool 10 can also include an angle head 47, as shown in 5 This angle head 47 contains an angle gear and can be rigidly connected to the work spindle 16 in such a way that the angle head 47 and the work spindle 16 form a single, movable unit. At its free end, the angle head has a tool holder receptacle 48 for receiving a tool holder 22 or the tool holder 42.

In a corresponding embodiment, the tool magazine 12 can also hold several such angle heads 47, which can be inserted and removed as needed. Angle heads with a large receptacle for tool holders 22 and angle heads with a small receptacle for tool holders 42 can be provided. It is also possible to provide angle heads of different orientations. For example, the one made of 3 A special adapter 49 is provided which holds a tool 50 with tool holder 42 in a position in which its body 43 points in the opposite direction to the body 23.

The machine tool 10 described so far and its tool changer 11 operate as follows:

It is initially assumed that one of the tools 13, 14, or 15 needs to be transferred to the work spindle 1. This process proceeds as with conventional machine tools, whereby the gantry loader 25 first picks up the relevant tool 13, 14, or 15 and transfers it to the gripper 29. The gripping disc 24 of the respective tool holder fits into the gripper contour 35, so that the tool holder 22 is securely held between the fingers 31 and 32. The tool holder 22 is then moved out of the gantry loader 25 by axial stroke of the gripper arm 28 in the direction of the pivot axis 30 and, by pivoting the gripper arm 28 180°, positioned in front of the tool holder receptacle 19 of the work spindle 16. By a reversing axial stroke of the gripper arm 28, the tool holder 22 is inserted into the tool holder receptacle 19 and clamped there. A lateral movement of the work spindle 16 in the X direction decouples the tool holder 22 from the gripper 29.

The removal of a tool or tool holder 22 from the work spindle 16 takes place in reverse order.

In the same way as the tool holder 22, the angle head 47 can be transferred to the work spindle 16 and coupled to it. If this angle head 47 is designed to accommodate tool holders 22 with a large gripper disc 24, this can be done using the large gripper contour 35 of the tool changer 27 by first moving the work spindle 16 from the horizontal position to 5 into the vertical position 6 The tool is pivoted. A 90° rotation about the tilting axis 18 is sufficient for this. The tool, now oriented horizontally and parallel to the pivoting axis 30, can be coupled to the gripper 29 again by moving the work spindle 16 in the X and Y directions and operated by it to effect a tool change. This is done as described at the beginning in connection with the tool holder 22.

If the angle head 47 has a smaller-sized receptacle 48 for the tool holder 42, the tool change procedure is modified:

The portal loader 25 retrieves the tool holder 22, which can be regarded as adapter 22-1, according to 4 or 3 The tool holder 42 is removed from the upper left of the tool magazine 12 storage compartment and presents the arrangement consisting of the adapter 22-1 and the tool holder 42, the tool changer 27. The tool changer 27, with its smaller gripper contour 36, now receives the tool holder 42 on its gripper disc 44, which fits into the smaller gripper contour 36. By axial stroke in the direction of the pivot axis 30, the tool holder 42 is moved out of the tool holder 22, which serves as adapter 22-1, i.e., in particular from the seat 45, and by pivoting 180° about the pivot axis 30, is positioned in front of the tool holder receptacle 48 of the angle head 47. 6 The tool holder 42 is positioned. By axial stroke, it is inserted into the tool holder receptacle 48. A transverse movement of the work spindle 16 in the X-direction decouples the tool holder 42 from the gripper 29.

During this tool change process, the tool holder 22 remains in the portal loader 25 as adapter 22-1 and is also transferred back to the storage area empty by it if required.

According to this concept, a whole number of different, smaller tools, such as the tool holder 42, can be successively transferred to and from the angle head 47 by the portal loader 25 and the tool changer 27. This allows the number of angle heads to be selected differently from the number of suitable tools, even if the tools to be held by the angle head or other spindle attachments differ dimensionally from the tool holder receptacle 19 provided in the work spindle 16.

It is also possible to operate angle heads with the tool changer 27, where the tool is positioned horizontally of the work spindle 16 according to 5 not pointing upwards, but downwards. If a swiveling movement of the work spindle 16 by 90° upwards is not possible, the work spindle 16 is used for tool changes similarly to the process described in... 6 downwards. In such a case, however, the tool points to the right, i.e., away from the work area. In this case, a tool change can be effected if the tool, as in 3 As can be seen, the special tool holder 49 is held in a position rotated by 180°. The portal loader 25 takes over the tool holder 49 and presents the tool 50 with tool holder 42 in this manner to the tool gripper 27. The gripper then takes over the tool, which is positioned rotated by 180°, and inserts it into the angle head 47, so to speak, "from behind." While the insertion of the tool holder 22 into the work spindle 16 normally occurs in a stroke movement in the Z-direction, directed away from the work area, the insertion of the tool 50 or tool holder 42 in the case of the angle head, with the tool pointing away from the work area, occurs in a stroke movement in the Z-direction, directed towards the work area.

The in 2 The illustrated tool gripper 29 has two gripper contours 35, 36, which are preferably arranged to overlap each other. This combined gripper 29 can grasp tool holders 22, 42 of different sizes and transport them back and forth between a work spindle or spindle attachment and a tool magazine 12. The range of application possibilities of the machine tool 10 is significantly expanded by the optional handling of tool holders 22, 42 of different sizes.

Reference symbol:

10

machine tool

11

Tool changer

12

Tool magazine

13 - 15

Tools

16

work spindle

17

drive axle

18

Tilting axis

19

Tool holder mount

20, 21

Tools

22

Tool holder

23

Body (e.g. conical or hollow conical)

24

Gripping discs

25

Portal loader

26

Arrow

27

Tool changer

28

Swivel arm

29

Grabber

30

Swivel axis (gripper axis)

31, 32

finger

33, 34

Swivel centers

35

first gripper contour

36

second gripper contour

37, 38

Circles

39, 40

Centers of circles 37, 38

41

line, radial to the pivot axis 30

42

Tool holder

43

conical body

44

gripping disc

45

seat

46

clamping contour

47

Angle drill head

48

Tool holder mount

49

Adapter for tool holder 42

50

Tool

Claims (11)

Machine tool (10) with at least one work spindle (16) having a tool holder mount (19), with a tool magazine (12) configured to hold several tool holders (22), and with a tool changer (27) having at least one gripper (29) having a first gripper contour (35) for a first tool holder (22) and a second gripper contour (36) for a second tool holder (42), wherein the gripper contours (35, 36) are assigned to different tool holders with different gripper disc diameters, in which the tool changer (27) is assigned an angle head (47) having a mounting contour (24) matching the first gripper contour (35), and in which the work spindle (16) is movable about a tilting axis (18) in order to pivot the work spindle (16) about the tilting axis (18) in the angle head (47) to orient the tool (13 - 15) taken up parallel to the pivot axis (30) of the tool changer (27). machine tool (10) according to Claim 1 , characterized in that the gripper (29) is arranged to pivot about a gripper axis (30) and that the gripper contours (35, 36) are arranged one behind the other as seen from the gripper axis (30). Machine tool (10) according to one of the preceding claims, characterized in that the gripper (29) is arranged pivotably about a gripper axis (30) and that the gripper contours (35, 36) define contour centers (39, 40) which are arranged on a radial (41) to the gripper axis (30). Machine tool (10) according to one of the preceding claims, characterized in that the two gripper contours (35, 36) define circular contours (37, 38) which are arranged overlapping each other. Machine tool (10) according to one of the preceding claims, characterized in that the first gripper contour (35) is larger than the second gripper contour (36). Machine tool (10) according to one of the preceding claims, characterized in that the gripper (29) has two fingers (31, 32), at least one of which is movably mounted towards the other. machine tool (10) according to Claim 6 , characterized in that the fingers (31, 32) are spring-loaded towards each other. Machine tool (10) according to one of the preceding claims, characterized in that an adapter (22) is associated with the tool changer (27) which has an adapter contour (24) which is configured to interact with one of the gripper contours (35, 36), and that the adapter (22) has a seat (45) which serves as a tool holder receptacle. machine tool (10) according to Claim 6 and 8 , characterized in that the adapter contour (24) is designed to fit the first gripper contour (35) and that the seat (45) is designed to fit a tool holder (42) which in turn fits the second gripper contour (36). machine tool (10) according to Claim 1 , characterized in that the angle head (47) has a driven tool holder receptacle (48). Method for changing tools on a machine tool (10) according to Claim 1 , characterized in that the angle head (47) remains on the work spindle (16) during at least one tool change, comprising the step of pivoting the work spindle about the tilting axis (18) to orient a tool (13 - 15) held in the angle head (47) parallel to the pivoting axis (30) of the tool changer (27).