Tool-changing device, machine tool having such a tool-changing device, and associated method
11318542 · 2022-05-03
Assignee
Inventors
- Florian Fehrenbacher (Lauterbach-Sulzbach, DE)
- Thorsten Rettich (Konigsfeld, DE)
- Reiner Jorg (Schramberg, DE)
Cpc classification
B23Q3/15553
PERFORMING OPERATIONS; TRANSPORTING
B23B3/16
PERFORMING OPERATIONS; TRANSPORTING
B23B29/326
PERFORMING OPERATIONS; TRANSPORTING
B23Q5/20
PERFORMING OPERATIONS; TRANSPORTING
B23Q3/155
PERFORMING OPERATIONS; TRANSPORTING
B23B2240/00
PERFORMING OPERATIONS; TRANSPORTING
International classification
B23B29/32
PERFORMING OPERATIONS; TRANSPORTING
B23Q5/20
PERFORMING OPERATIONS; TRANSPORTING
B23Q3/155
PERFORMING OPERATIONS; TRANSPORTING
B23B1/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A tool-changing device which is used on machine tools (18). Here, provision is made to carry out positioning of a tool holder (2) in the working position (6) of the tool holder with the aid of the locking element (7) of the drive device (4) of the tool-changing device (1). An adjusting movement (22) of the locking element (7) into the locking position (9) of the locking element on the tool holder (2) that is required for the use of the tool (3) is used to position the tool holder (2) in the working position (6) thereof, by the adjusting movement (2) of the locking element (7) being converted into a positioning movement (21) of the tool holders (2).
Claims
1. A tool-changing device (1), comprising at least two tool holders (2) for holding one tool (3) each, a drive device (4) through which the tool holders (2) are movable relative to at least one of a frame (5) or a base body (5a) of the tool-changing device (1) into a working position (6), the drive device (4) includes at least one locking element (7) and at least one counter element (8), which is connected at least indirectly to the at least two tool holders (2), and the at least two tool holders (2) are movable into different positions through a relative adjusting movement (22) between the locking element (7) and the counter-element (8) into the working position (6) in which the tool holders (2) are lockable, and the adjusting movement (22) is carried out by engagement of the locking element (7) and the counter element (8) with one another, and the adjusting movement (22) positions the tool holders (2) into the working position (6), such that the respective tool holder (2) is positionable into the working position (6) in a positioning movement (21) when the locking element (7) and the counter element (8) are locked together.
2. The tool-changing device (1) as claimed in claim 1, wherein the locking element (7) and the counter element (8) interact to produce the relative adjusting movement (22) by a movement of the locking element (7) into a locking position (9) executed relative to the counter element (8), or by a movement of the counter element (8) into a locking position (9) on the locking element (7) executed relative to the locking element (7), such that the respective movement is converted into a positioning movement (21) of the counter element (8), and wherein the tool holders (2) are brought into the working position (6) by the positioning movement (21).
3. The tool-changing device (1) as claimed in claim 2, wherein the positioning movement of the counter element (8) is a linear movement or a rotary movement around an axis of rotation of the tool head (23), with the tool holders (2) rotating along a closed path around the axis of rotation (R).
4. The tool-changing device (1) as claimed in claim 1, wherein the counter element (8) has at least one of a tooth profile or claw profile (1) that corresponds to the locking element (7).
5. The tool-changing device (1) as claimed in claim 1, wherein the tool holders (2) are connected to the counter element (8) such that a relative movement between the tool holders (2) and the counter element (8) is prevented.
6. The tool-changing device (1) as claimed in claim 1, further comprising a tool head (23) on which the at least two tool holders (2) are attached, and the tool head is movable relative to at least one of the frame (5) or the base body (5a).
7. The tool-changing device (1) as claimed in claim 6, wherein the locking element (7) is attached to at least one of the frame (5) or the base body (5a) and the counter element (8) is attached on the movable tool head (23), or the locking element (7) is attached one the movable tool head (23) and the counter element (8) is attached to the frame (5).
8. The tool-changing device (1) as claimed in claim 1, wherein the locking element (7) is axially fixed as a claw element (13) relative to the counter element (8) and the counter element (8) is a rotatable counter claw element (12) which is axially moveable at least one of relative to an axis of rotation (R) thereof or relative to the counter element (8), and both the claw element and the counter claw element have at least one claw edge (15) which is angled relative to the axis of rotation (R) of the counter element (8) and the claw edges (15) correspond to one another, so that the adjusting movement (22) is transferrable through the claw edges (15) into a rotary positioning movement (21) by the counter element (8).
9. The tool-changing device (1) as claimed in claim 1, further comprising a positioning device (16) by which a positioning force is transferrable, at least indirectly, to the tool holders (2), and the locked counter element (8) in an unlocked state together with the tool holders (2) are automatically positionable or moved further away from the working position (6) into an engaging position (17) by the positioning force, and where the locking element (7) is again engagable with the counter element (8) or vice versa.
10. The tool-changing device (1) as claimed in claim 9, wherein a level of the positioning force required depends on the relative position of the locking element (7) and the counter element (8) relative to one another, and the positioning force reaches a maximum level when the locking element (7) is in the locking position.
11. The tool-changing device (1) as claimed in claim 10, wherein the positioning force reaches a minimum level when the counter element (8) is in an engaging position (17) and otherwise acts in or against a direction of a positioning movement (21) by the tool holders (2).
12. The tool-changing device (1) as claimed in claim 11, wherein the positioning device (16) is at least one of positioned between the frame (5) or the base body (5a) of the tool-changing device (1) and the counter element (8), or a magnetic positioning device (16).
13. The tool-changing device (1) as claimed in claim 1, wherein the drive is at least one of an electric, electromagnetic, pneumatic, or and/or hydraulic drive used to generate a tool feed.
14. A machine tool (18) comprising the tool-changing device (1) as claimed in claim 1.
15. The machine tool (18) as claimed in claim 14, wherein the machine tool (18) includes the drive device (4) which is adapted to generate a tool feed that is synchronised with workpiece rotation and the adjusting movement (22) between the locking element (7) and the counter element (8), and the machine tool (18) further comprises a locking device (24) by which the locking element (7) of the tool-changing device (1) is attachable relative to a frame (5) of the machine tool (18), at least for periods in which tools are changed.
16. A method for changing a tool (3) using a tool-changing device (1) according to claim 1, comprising bringing the tool holder (2) on the tool-changing device (1) which holds the tool (3) into a working position (6) through the relative adjusting movement (22) between the locking element (7) and the counter element (8).
17. The method as claimed in claim 16, further comprising moving the locking element (7) used to position the tool holder (2) into a locking position (9) in order to secure the counter element (8), or moving the counter element (8) used to position the tool holder (2) into a locking position (9), wherein the adjusting movement (22) is converted into a positioning movement (21) by the counter element (8), with the tool holder (2) fixed into the working position (6) while at least one of the locking element (7) or the counter element (8) reaches the locking position (9).
18. The method as claimed in claim 17, wherein the tool holder (2) moves from the working position (6) into an intermediate position or an engaging position (17) after releasing the locking element (7) or the counter element (8) from the locking position (9).
19. The method as claimed in claim 18, further comprising moving the tool holder (2) from the working position (6) into an intermediate position or an engaging position (17) using a positioning device (16).
20. The method as claimed in claim 19, further comprising operating a tool feed at least one before or after changing the tool using the drive device, with the tool feed being at least one of parallel to the adjusting movement or synchronised with workpiece rotation, as part of a chip machining process.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The following section provides detailed descriptions using one example of the invention given in the drawing. They are shown in an illustration that, in parts, follows a highly schematic representation:
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DETAILED DESCRIPTION
(14) Together, the above figures show a tool-changing device that is referred to as element 1. The tool-changing device 1 is used with the machine tool 18, shown at least partially in
(15) The tool-changing device 1 is fitted with a tool head 23. A total of four tool holders 2 arranged at intervals of 90 degrees from other another are attached to the tool head 23. A tool 3 is attached to each tool holder 2. The tool-changing device 1 features a drive device 4, which moves the tool holders 2 relative to the frame 5 of the machine tool 18 and also relative to the base body 5a of the tool-changing device 1 into a working position. The working position is shown in
(16) The drive device 4 comprises a locking element 7 and a counter element 8. The tool head 23 fitted with the tool holders 2 is connected to the counter element 8. The locking element 7 and the counter element 8 engage mechanically in such a way that the four tool holders 2 on the tool head 23 can be moved in turn into the working position 6 and engage there with the locking element 7. In the sample design given in the examples shown in the figures, the tool holders 2 are brought into position by moving the counter element 8 into its locking position relative to the locking element 7, e.g. as shown in
(17) Over the course of the adjusting process, the locking element 7 engages mechanically with the counter element 8 in such a way that the linear adjusting movement by the counter element 8 into its locking position 9—as illustrated by arrow 22 in
(18) As such, the counter element 8 is brought into either a relative position or a position that corresponds to the working position 6 of the tool holders 2. The corresponding position or relative position of the counter element 8 is shown in
(19) The positioning movement 21, whose effect is transferred to the tool holders 2 on the tool head 23 through the use of the locking element 7 and the counter element 8 is a rotary movement which moves around an axis of rotation R set by the tool head 23 and the counter element 8. The adjusting movement 22 that is prompted by the counter element 8 is a linear movement that moves in the direction of the rotation axis R set by the tool head 23 and the counter element 8 relative to the locking element 7, which is itself in an axially fixed position.
(20) The counter element 8 features a claw profile 10. The locking element 7 features a corresponding claw profile 10. When the counter element 8 engages with the claw profile 10 on the locking element 7, the counter element 8 can be rotated. Through the retaining ring 19, the locking element 7 stays in place in the axial direction on the base body 5a of the tool-changing device 1, i.e. it is axially fixed relative to the axis of rotation R. The locking element 7 is mounted on the base body 5a of the tool-changing device 1 relative to the axial direction. This effect is clear when one compares the two positions taken by the locking element 7, which are shown in
(21) The tool holders 2 are connected to the counter element 8 through the tool head 23 in a way that prevents a relative movement by the tool holders 2 and the counter element 8. The tool holders 2 are connected to the counter element 8 through the tool head 23 so that they cannot rotate.
(22) In particular,
(23) The locking element 7 is arranged onto the base body 5a. The counter element 8 is attached to the side through the movable tool head 23. The base body 5a has a bracket 5b that can be seen across the figures. This bracket 5b is used to attach a glass scale (not shown), through which the movement of the base body 5a relative to the frame 5 of the machine tool 18 can be monitored.
(24) To fasten the base body 5a to a corresponding part of the machine tool 18, a circumferential flange 5c can be used.
(25) The counter element 8 is a counter claw element 12 onto which one of the claw profiles 10 mentioned above is attached. The locking element 7 is designed as a claw element 13 which is axially fixed relative to the axis of rotation R and relative to the counter element 8, which in turn features the other claw profile 10 mentioned above, and is also rotationally fixed relative to the base body 5a. The locking element 7 is designed as a claw element 13 and is similar in its function to an axially fixed claw jaw, in that it is not axially displaced relative to the axis of rotation R during the tool-changing process. The counter element 12, meanwhile, is designed as a counter claw element 8 and is similar to an axially displaced claw sleeve. In the example given here, the counter element 8 is moved relative to the locking element 7, which is stationary, at least during the changing process.
(26) The locking element 7 and the counter element 8 have matching engaging surfaces 14 on the claw edges 15 of their claw profiles 10. The engaging surfaces 14 and the claw edges 15 are aligned with the axis of rotation R. The engaging surfaces 14 and claw edges 15 are aligned at an angle to the axis of rotation R. Through the angled positions of the engaging surfaces 14, a drive force from the counter element 8 can be deflected and the axial adjusting movement 22 of the counter element 8 can be transferred into a rotational positioning movement 21 by the counter element 8. Similarly, through their angled positions, the engaging surfaces 14 and the claw edges 15 determine the positioning movement's direction of rotation.
(27) Both the locking element 7 and the counter element 8 have a total of four claw projections 15a and, relative to one another, the claw edges 15 are offset by 90 degrees around the counter element's axis of rotation R. This enables the locking element 7 to move the counter element 8 into four different positions and for these positions to be secured. The design of the claw projections 15a and claw edges 15 corresponds to the design of the tool holders 2. Additionally, the number of claw edges 15 provided at an angle on the locking element 7 corresponds to the number of angled claw edges 15 provided on the counter element 8, as well as to the number of tool holders 2.
(28) The tool-changing device 1 also features a positioning device 16. This positioning device 16 is used to move the counter element 8 when it is released from the locking element 7. Such a movement achieves the aim of enabling the locking element 7 to engage with the counter element 8 in order to position subsequent tool holders 2 into the working position 6 and, finally, to secure the counter element 8 and the positioned tool holder 2 in place.
(29) To this end, the positioning device 16 is designed to generate a positioning force that can be transferred through the counter element 8 to the tool head 23 and the tool holders 2. The positioning force is used to move each of the four tool holders 2 automatically and, in particular, to move the counter element 8 from the working position 6 to an intermediate position, as the counter element 8 moves from the locking position 9. In this intermediate position, the counter element 8 is arranged in an engaging position 17 relative to the locking element 7.
(30) The engaging position 17 is shown through the dotted line in
(31) The level of positioning force required by the positioning device 16 depends on the relative position of the counter element 8 to the locking element 7. This means that the positioning force takes on a maximum value in the relative position of the counter element 8 to the locking 7 that corresponds to the working position 6, i.e. when the counter element 8 is fixed into position by the locking element 7 (
(32) The positioning force described above moves through the successive relative positions of the counter element 8 to the locking element 7, alternates its movement between the direction of the positioning movement 21 of the tool holders 2 and the opposite direction, and also takes on a value of zero in the engaging position 17. This means that when the counter element 8 is released by the locking element, the counter element 8 takes on a secure intermediate position, thanks to the positioning force provided by the positioning device 16.
(33) In the engaging position 17, the positioning device 16 applies a holding force to hold the counter element 8 in the engaging position 17 for subsequent engagement of the locking element 7. Regardless of the direction in which the counter element 8 moves from the engaging position 17, the positioning device 16 automatically applies a positioning force both in the direction of the engaging position 17 and in the opposite direction.
(34) The positioning device 16 is formed between the base body 5a of the tool-changing device 1 and the counter element 8, which rotates relative to this position. The positioning device 16 is a magnetic positioning device and features a retaining ring 20 with four magnets 20a that are distributed evenly around the counter element's 8 axis of rotation R. Through two bearings 19, the counter 8 is mounted onto the base body 5a of the tool-changing device 1 in such a way that it can be rotated. The base body 5a of the tool-changing device 1 can therefore also be referred to as a housing structure for these elements.
(35) The retaining ring 20 featuring the magnets 20a holds the counter element 8 in the position of use on the outside of the device and is attached to the base body 5a of the tool-changing device 1. On the counter element 8, four counter magnets 20b are arranged at even intervals around the counter element's 8 axis of rotation R, are assigned to their respective magnets 20a on the retaining ring 20, and, as such, also form part of the magnetic positioning device 16. The magnets 20a and counter magnets 20b are arranged according to their polarity in such a way that they attract one another when in the engaging position 17 between the counter element 8 and the locking element 7, as shown in
(36) When the magnets 20a and counter magnets 20b are displaced from the position shown in
(37) The positioning force produced by the magnets 20a and counter magnets 20b is less than the force applied by the counter element 8, which results in a positioning force through the claw edges 15 on the claw-based locking element 7 and the claw-based counter element 8. As such, the positioning force produced by the positioning device 16 can be overcome through the counter element 8, and the counter element 8 can in turn be rotated further to move the next tool holder 2 in the series into the working position 6. The counter element 8 can therefore be described as a rotary slide, through which an axial movement by the counter element 8 can be transferred into a rotary positioning movement 21 by the counter element 8.
(38) A magnet 20a and a counter magnet 20b are attached to each of the four tool holders 2 on the tool head 23, so that the positioning device 16 has a total of four magnets 20a and four counter magnets 20b, each separated by 90 degrees around the counter element's 8 axis of rotations R.
(39) The drive device 4 comprises a drive for axial adjustment of the locking element 7. This drive is part of the drive device 4 on the machine tool 18 and is an electromagnetic drive device 4 that allows for lifting movements at high frequencies.
(40) As such, the machine tool 18 features a drive device 4, which is designed to generate a tool feeder and the adjusting movement between the locking movement 4 between the locking element 7 and the counter element 8. This in turn means that a separate drive device to provide the adjusting movement during tool changes is not necessary.
(41) The machine tool 18 is additionally made up of a locking device 24 with a locking tappet 25. Through the locking device 24 and the locking tappet 25, the locking element 7 of the tool-changing device 1 can be attached relative to the frame 5 of the machine 18 during the tool changing process. To this end, the locking tappet 25 is inserted into a corresponding recess 26 on the locking element 7. In this position, shown for example in
(42) To prevent unintended release of the counter element 8 from the locking element 7 during high-frequency, oscillating feeder movement from the drive device 4, a compression spring 27 is included which secures the locking element 7 in its locking position on the counter element 8.
(43)
(44) In
(45) In
(46) In
(47) In
(48) In
(49) The tool-changing device 1 described above can be used to carry out the process for changing tools 3 on a machine tool 18 as described below.
(50) In this process, a tool holder 2 carrying the tool 3 on the tool-changing device 1 reaches a working position 6, by bringing the counter element 8 on the tool-changing device 1 into a locking position 9 on the locking element 7. To position the tool holder 2, the counter element 8 engages with the locking element 7 and moves relative to it.
(51) As already described above, the tool holders 2 and counter element 8 are connected to one another in a rotationally fixed way. Generally, the tool holders 2 and the counter element 8 must be connected to one another in such a way that a relative movement between them is impossible. Once the counter element 8 reaches its locking position 9 on the locking element 7, the tool holder reaches the working position 6 and is fixed into this position by the locking element 7. Once the counter element 8 is released from its locking position 9 (
(52) The invention relates to improvements in the area of so-called tool-changing devices 1, which are used on machine tools 18. Here, provision is made to carry out positioning of a tool holder 2 in the working position 6 of the tool holder with the aid of the locking element 7 of the drive device 4 of the tool-changing device 1. An adjusting movement 22 of the locking element 7 into the locking position 9 of the locking element on the tool holder 2 that is required for the use of the tool 3 is used to position the tool holder 2 in the working position 6 thereof, by the adjusting movement 2 of the locking element 7 being converted into a positioning movement 21 of the tool holders 2 (cf.
LIST OF KEY TERMS
(53) 1 Tool-changing device
(54) 2 Tool holder
(55) 3 Tool
(56) 4 Drive device
(57) 5 Frame
(58) 5a Base body of 1
(59) 5b Bracket
(60) 5c Flange
(61) 6 Working position
(62) 7 Locking element
(63) 7a Guiding element of 1
(64) 8 Counter element
(65) 9 Locking position
(66) 10 Claw profile
(67) 11 Carrier plate
(68) 12 Counter claw element
(69) 13 Claw element
(70) 14 Engaging surfaces
(71) 15 Claw edges
(72) 15a Claw projections on 7 and 8
(73) 16 Positioning device
(74) 17 Engaging position
(75) 18 Machine tool
(76) 19 Bearing
(77) 20 Retaining ring
(78) 20a Magnet
(79) 20b Counter magnet
(80) 21 Positioning movement
(81) 22 Adjusting movement
(82) 23 Tool head
(83) 24 Locking device
(84) 25 Locking tappet
(85) 26 Recess
(86) 27 Compression spring
(87) R Rotation axis of 8