Machine tools and methods for ejecting workpiece parts

Abstract

The invention relates to machine tools and methods for processing plate-like workpieces. The machine tool comprises a first movement device for the movement of the workpiece in a first direction, two workpiece supporting surfaces spaced apart by a gap extending in a second direction and configured for supporting the workpiece, and a second movement device for the movement of a pressing tool in the second direction. The pressing tool comprises two tool components that are configured to move in a stroke direction relative to one another in order to process the workpiece in the gap by at least one of stamping and shaping. The machine tool also comprises at least one receiving device configured to move in the second direction one or more of in and along the gap for depositing at least one workpiece part formed when processing the workpiece by at least one of stamping and shaping.

Claims

1. A machine tool for processing a workpiece, comprising: a pressing tool; a first movement device configured to move the workpiece in a first direction (X); two workpiece supporting surfaces configured to support the workpiece, wherein the two workpiece supporting surfaces are spaced apart by a gap extending in a second direction (Y); a second movement device configured to move the pressing tool in the second direction (Y), wherein the pressing tool comprises two tool components that are configured to move in a stroke direction (Z) relative to one another to process the workpiece in the gap by stamping, wherein the pressing tool further comprises a receiving device configured to move in the second direction (Y) in the gap for depositing at least one workpiece part cut off from the workpiece when processing the workpiece by the stamping, wherein the receiving device comprises a controllable ejection device for ejecting the at least one workpiece part deposited in the receiving device; and a control device configured to control the movement of the receiving device at different ejection positions (Y.sub.A1, . . . Y.sub.A3) along the gap and configured to control the ejection device to cause ejection of the at least one workpiece part at the different ejection positions (Y.sub.A1, . . . Y.sub.A3).

2. The machine tool of claim 1, wherein the receiving device is attached to one of the two tool components and is configured to be moved in the gap together with the tool component.

3. The machine tool of claim 1, wherein the receiving device comprises a parts container for depositing the at least one workpiece part.

4. The machine tool of claim 1, wherein the controllable ejection device comprises at least one pivotable flap configured to move into a first pivoted position (S1) for supporting the at least one workpiece part deposited in the receiving device and into a second pivoted position (S2) for ejecting workpiece parts from the receiving device.

5. The machine tool of claim 4, wherein a pivot axis of the at least one pivotable flap is aligned parallel with or perpendicular to the second direction (Y).

6. The machine tool of claim 4, wherein the at least one pivotable flap is configured to move into a third pivoted position (S3) for ejecting the at least one workpiece part from the receiving device, wherein an ejection direction (A1) in the second pivoted position (S2) differs from an ejection direction (A2) in the third pivoted position (S3).

7. The machine tool of claim 4, wherein the at least one pivotable flap forms a bottom region of a parts container.

8. The machine tool of claim 7, further comprising a further pivotable flap formed on a side region of the parts container and configured to have a first pivoted position (S1), wherein the further pivotable flap is adjacent to the bottom region of the parts container formed by the at least one pivotable flap, wherein the further pivotable flap is configured to have a second pivoted position (S2), wherein the further pivotable flap is spaced apart from the bottom region of the parts container.

9. The machine tool of claim 8, wherein the at least one pivotable flap and the further pivotable flap are coupled together in terms of movement.

10. The machine tool of claim 1, wherein the ejection device comprises at least one ejection chute for ejecting the at least one workpiece part from the receiving device in an ejection direction (A1, A2).

11. The machine tool of claim 10, wherein the ejection direction (A1, A2) extends transversely to the second direction (Y).

12. The machine tool of claim 1, wherein the receiving device comprises a feeding chute for feeding the at least one workpiece part from one of the tool components of the pressing tool.

13. The machine tool of claim 12, further comprising a sensor device for detecting the at least one workpiece part that pass the feeding chute or that protrude upwardly out of a parts container.

14. The machine tool of claim 1, wherein the receiving device is arranged below a continuous opening in a lower of the two tool components of the pressing tool.

15. The machine tool of claim 14, further comprising at least one guide element for guiding the at least one workpiece part when ejected from the receiving device into one or more collection containers arranged inside the gap.

16. A machine tool for processing a workpiece, comprising: a pressing tool; a first movement device configured to move the workpiece in a first direction (X); two workpiece supporting surfaces configured to support the workpiece, wherein the two workpiece supporting surfaces are spaced apart by a gap extending in a second direction (Y); a second movement device configured to move a the pressing tool in the second direction (Y), wherein the pressing tool comprises two tool components that are configured to move in a stroke direction (Z) relative to one another to process the workpiece in the gap by stamping, wherein the pressing tool further comprises a receiving device configured to move in the second direction (Y) in the gap for depositing at least one workpiece part cut off from the workpiece when processing the workpiece by the stamping, wherein the receiving device comprises a controllable ejection device for ejecting the at least one workpiece part deposited in the receiving device wherein the controllable ejection device comprises at least one pivotable flap configured to move into a first pivoted position (S1) for supporting the at least one workpiece part deposited in the receiving device and into a second pivoted position (S2) for ejecting workpiece parts from the receiving device, and wherein the at least one pivotable flap is configured to move into a third pivoted position (S3) for ejecting the at least one workpiece part from the receiving device, wherein an ejection direction (A1) in the second pivoted position (S2) differs from an ejection direction (A2) in the third pivoted position (S3).

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows a schematic view of an example of an embodiment of a machine tool in the form of a stamping press with a receiving device that is able to be moved within a gap for depositing workpiece parts.

(2) FIGS. 2A-2D show four schematic views of a receiving device with a parts container for receiving workpiece parts.

(3) FIGS. 3A-3B show two views of a receiving device with a pivotable flap in a first pivoted position and a second pivoted position.

(4) FIGS. 4A-4B show two views of details of the machine tool of FIG. 1 with a receiving device arranged below a stamping die.

DETAILED DESCRIPTION

(5) Identical reference numerals are used in the following description of the drawings for components that are the same and/or functionally the same.

(6) FIG. 1 shows an example of a machine tool 1 in the form of a stamping press that in the example shown is configured for processing a plate-like workpiece 2 in the form of a metal sheet, by stamping and optionally by shaping. The machine tool 1 comprises a first movement device 3 configured to move the workpiece 2 in the direction 3 to displace the workpiece 2 supported on two workpiece supporting surfaces 4a, 4b shown in dashed lines in a first direction (X-direction hereinafter) of an XYZ coordinate system shown in FIG. 1. The workpiece supporting surfaces 4a, 4b may, for example, be formed on the upper face of workpiece tables that are provided with rollers (not shown) for the support of the workpiece 2. The first movement device 3 may comprise a numerically controlled coordinate guide that laterally clamps the workpiece 2 and moves the workpiece in the X-direction over the workpiece supporting surfaces 4a, 4b.

(7) The machine tool 1 comprises, in the example shown, an O-shaped machine frame 5 that is arranged between the workpiece supporting surfaces 4a, 4b and that encloses a frame interior 6 that forms the processing region of the stamping press. A gap 7 is formed in the frame interior 6 between the workpiece supporting surfaces 4a, 4b. The gap extends in a second direction (Y-direction hereinafter) perpendicular to the X-direction. A second movement device 8 serves for moving a pressing tool 9 in the Y-direction along the gap 7, as indicated by double-headed arrow 8. The pressing tool 9 comprises a first upper tool component in the form of a stamping punch 9a and a second lower tool component in the form of a stamping die 9b. The stamping die 9b has a die opening into which the stamping punch 9a penetrates during the stamping processing of the workpiece 2. For the movement of the stamping punch 9a in a stroke direction (Z-axis hereinafter) the machine tool 1 has a stroke drive 10 that acts on a plunger, wherein the stamping punch 9a is attached to the lower end thereof.

(8) The second movement device 8 comprises an upper and lower drive spindle 11a, 11b, which are rotatably connected to the machine frame 5 and the stroke drive 10 with the stamping punch 9a and/or the stamping die 9b are attached to the spindle nuts thereof to move the stamping punch and/or stamping die in the Y-direction. To this end, the second movement device 8 comprises a motorized drive, not shown in more detail, by which the stamping punch 9a and the stamping die 9b can be moved synchronously in the gap 7 and/or in the frame interior 6. The second movement device 8 can optionally be configured to displace the stamping die 9b independently of the stamping punch 9a in the Y-direction. The second movement device 8 may have two separately controllable drives, but it is also possible that the movement device 8 has only one motorized drive and the synchronous movement of the stamping punch 9a and the stamping die 9b takes place via a mechanical coupling gear.

(9) In the example shown, the machine tool 1 comprises a receiving device 12 for depositing workpiece parts 2a (see FIG. 2c) that are separated from the workpiece 2 during the processing by stamping. The receiving device 12 can be moved in the Y-direction in the gap 7 and in the example shown is attached and/or mounted on the stamping die 9b, more specifically on a stamping support connected thereto and that forms a part of the spindle nut of the lower drive spindle 11b. The receiving device 12 also forms a part of the spindle nut of the lower drive spindle 11b and can be moved in the gap 7 together with the stamping die 9b by means of the second movement device 8.

(10) The machine tool 1 comprises a control device 13 that, amongst other things, numerically controls the first and second movement devices 3, 8 as well as the stroke drive 10. The control device 13, in the example shown, is configured and/or programmed to move the receiving device 12 together with the stamping die 9b in a controlled manner to different ejection positions Y.sub.A1, . . . Y.sub.A3 along the gap 7, in order to eject workpiece parts 2a deposited in the receiving device 12 laterally out of the gap 7. The control device 13 selects the ejection position Y.sub.A1, . . . Y.sub.A3 depending on the type, in particular on the geometry, of the workpiece parts 2a deposited in the receiving device 12. In the example shown in FIG. 1, in each case a box-shaped collection container 14 is arranged at a respective ejection position Y.sub.A1, . . . Y.sub.A3 to receive the workpiece parts 2a deposited in the receiving device 12 and ejected at the ejection position Y.sub.A1, . . . Y.sub.A3. By means of the receiving device 12, in this manner workpiece parts 2a may be ejected and thus sorted depending on their type and/or geometry into different collection containers 14. For simplification purposes, only three collection containers 14 are shown in FIG. 1, but generally collection containers 14 are arranged along the entire extent of the gap 7 in the Y-direction.

(11) For ejecting workpiece parts 2a at a respective ejection position Y.sub.A1, . . . YA3 the receiving device 12 comprises an ejection device 15 that is subsequently described in more detail with reference to FIG. 2A and FIG. 2B. The receiving device 12 in the example shown in FIGS. 2a, b comprises a box-shaped parts container 16, into which workpiece parts 2a can be deposited and collected. The parts container 16 has a cross section that widens toward the bottom region to prevent jamming of the workpiece parts 2a. In the example shown, the ejection device 15 comprises a pivotable flap 17 that forms a bottom region of the parts container 16. The flap 17 is pivotable from a first substantially horizontal pivoted position S1 shown in FIG. 2A for supporting workpiece parts 2a into a second pivoted position S2 shown in FIG. 2B. In the first pivoted position S1 the flap 17 closes the parts container 16, and in the second pivoted position S2 the flap 17 is inclined downwardly by ca. 30 relative to the first pivoted position S1, whereby the workpiece parts 2a supported on the flap 17 slide along the upper face of the flap 17 in order to empty the parts container 16 and to eject the workpiece parts 2a sideways out of the gap 7. A pivot axis 18 of the pivotable flap 17 extends in the Y-direction so that the workpiece parts 2a are ejected via the flap in an ejection direction A1 that extends in a plane transversely to the Y-direction and thus transversely to the gap 7.

(12) In the example shown in FIGS. 2A and 2B, the ejection device 15 comprises an actuator in the form of a cylinder 19 that is able to be pneumatically actuated by means of the control device 13 (see FIG. 2D) and that is attached to the outer face of the parts container 16, in order to pivot the pivotable flap 17 from the first pivoted position S1 into the second pivoted position S2 and vice-versa. As has been described above, the angle between the first pivoted position S1 and the second pivoted position S2 of the flap 17 in the example shown is only ca. 30 so that the opening formed between the lower end of the flap 17 located in the second pivoted position S2 and the parts container 16 is at a relatively low height.

(13) The ejection device 15 in the example shown has a further pivotable flap 20 that is attached to a side region of the parts container 16 and that is attached approximately at the height of the lower third of the side region in an articulated manner to the parts container 16 so as to enlarge the opening and in this manner to simplify the emptying of the parts container 16. In a first pivoted position S1 shown in FIG. 2A, the further flap 20 adjoins the flap 17 located in the first pivoted position S1 and forms in the first pivoted position S1 a part of the side wall of the parts container 16. Workpiece parts 2a bearing against the flap 17 in the first pivoted position S1 are thus prevented by the further flap 20 from falling out to the side from the parts container 16. In the example shown, the further flap 20 on the side region of the parts container 16 is coupled in terms of movement to the flap 17 on the bottom region of the parts container 16 via a mechanical coupling gear 21. By means of the coupling in terms of movement, when the actuator 19 and/or the cylinder are actuated, the further flap 20 is synchronously pivoted with the flap 17, so that the flap 17 and the further flap 20 are pivoted together from the first pivoted position S1 into the second pivoted position S2 and vice-versa. In the second pivoted position S2, shown in FIG. 2b, the further flap 20 is pivoted upwardly by an angle of ca. 30 and protrudes to the side over the side region of the parts container 16. In the second pivoted position S2, the further flap 20 is thus spaced apart from the flap 17 forming the bottom region and increases the height of the opening via which the parts container 16 may be emptied. By means of the enlarged opening, relatively large workpiece parts 2a may also be ejected from the parts container 16.

(14) FIG. 2C shows a detail of the receiving device 12 with the lower end of the parts container 16 in which the pivotable flap 17 and the further pivotable flap 20 are arranged in the second switching position S2. As can be identified in FIG. 2C, the ejection device 15 has an ejection chute 22 that adjoins the flap 17 located in the second pivoted position S2, to eject workpiece parts 2a in the ejection direction A1 transversely to the Y-direction and thus transversely to the gap 7. As may also be identified in FIG. 2C, a light barrier 23c is formed at the lower end of the ejection chute 22 between a transmitter 23a and a receiver 23b, to detect workpiece parts 2a that have passed the ejection chute 22 and thus have been moved into a collection container 14 shown in FIG. 1. A deflection plate 24 is attached to a frame above the lower end of the ejection chute 22 to guide the workpiece parts 2a in the ejection direction A1 to one respective collection container 14. The deflection plate 24 prevents workpiece parts 2a from jumping over the light barrier 23c and optionally the collection container 14, due to vibrations caused by the process.

(15) FIG. 2D shows a sectional view of the upper edge of the parts container 16, a sensor device 25 with a transmitter 25a and receiver 25b formed on opposing sides of an upper opening of the parts container 16 being provided thereon, a two dimensional light grid 25c being produced therebetween to monitor whether workpiece parts 2a protrude upwardly from the parts container 16, i.e. to monitor whether the parts container 16 is completely full.

(16) The sensor device 25 also makes it possible to monitor whether a workpiece part 2a has passed or not passed a feeding chute 26 for feeding workpiece parts 2a from the stamping die 9b to the parts container 16 and/or to the receiving device 12. To this end, the light grid 25c of the sensor device 25 is formed at the lower end of the feeding chute 26. As may also be identified in FIGS. 2A-2D, the feeding chute 26 at its upper end has a collar 27 that at the side partially surrounds the circular outer contour of the stamping die 9b. If the workpiece parts 2a are to be conveyed into the parts container 16, the center of gravity thereof not being located above the feeding chute 26 after the workpiece 2 has been cut out, a relative movement can be produced between the stamping die 9b and the workpiece part 2a supported thereon, by the stamping die 9b being moved sufficiently rapidly in the Y-direction in the gap 7 that the stamping die 9b is pulled away under the workpiece part 2a and the feeding chute 26 is positioned below the workpiece part 2a.

(17) The parts container 16 may be provided on its upper face with a workpiece supporting surface (not shown) that is moved with the receiving device 12 in the gap 7. A lateral opening remains between the feeding chute 26 and the workpiece supporting surface, which is sufficiently large, to accommodate the workpiece parts 2a in the parts container 16. Also, parts of a workpiece supporting surface may optionally be attached to the stamping die 9b, the workpiece supporting surface being moved with the stamping die 9b in the gap 7.

(18) FIGS. 3A and 3B show a further example of a receiving device 12, which differs from the receiving device 12 described in connection with FIGS. 2A-2D in that a parts container 16 is not provided for collecting workpiece parts 2a: in the case of the receiving device 12 shown in FIGS. 3A and 3B, instead a workpiece part 2a is directly deposited on a flap 17 that at the same time is part of an ejection device 15 and that is located in FIG. 3A in a first horizontal pivoted position S1. Optionally, a plurality of workpiece parts 2a can be deposited and/or collected on the flap 17 serving as a supporting surface before they are ejected from the ejection device 12. To this end, the pivotable flap 17 may be pivoted into a second pivoted position S2, not illustrated in FIGS. 3A and 3B, in which the workpiece part 2a supported on the flap 17 is ejected in a first ejection direction A1 via a fixed ejection chute 22 into a collection container, not shown in FIGS. 3A and 3B, and which, for example, may be arranged at the side adjacent to the gap 7 below the second workpiece supporting surface 4b of the machine tool 1.

(19) FIG. 3B shows the flap 17 in a third pivoted position S3 that is inclined downwardly by ca. 30 relative to the first pivoted position S1 shown in FIG. 3A. In the third pivoted position S3, the workpiece part 2a is conveyed onto a further ejection chute 22a, the workpiece part 2a being able to slide along the chute and being able to be collected in a collection container, not illustrated, which for example may be arranged below the first workpiece supporting surface 4a of the machine tool 1. The receiving device 12 shown in FIGS. 3A and 3B, thus permits an ejection of workpiece parts 2a on both sides of the gap 7. Also, the receiving device 12 shown in FIGS. 2A-2D, more specifically the ejection device 15 thereof, may optionally be configured such that workpiece parts 2a may be ejected on both sides of the gap 7.

(20) The receiving device 12 shown in FIGS. 3A and 3B, similar to the receiving device 12 shown in FIGS. 2A-2D, has a feeding chute 26 to convey workpiece parts 2a from the stamping die 9b to the pivotable flap 17. The flap 17 that is able to pivot about a pivot axis 18 parallel to the Y-direction has a stop 28 at its side located opposite the feeding chute 26. The flap 17 is pivoted by means of an actuator into the three different pivoted positions S1 to S3, wherein the actuator, for example, may be configured as described in EP 0 945 196 A2. The flap 17 may optionally also be pivoted about more than one pivot axis, as is also described in EP 0 945 196 A2.

(21) Instead of the pivotable flap 17 the receiving device 12 shown in FIGS. 3A and 3B can, for example, have an endless conveyor belt that is able to be optionally controlled in its direction of movement, workpiece parts 2a being able to be deposited thereon and the workpiece parts 2a being able to be optionally transported thereby to one of the two ejection chutes 22, 22a or optionally directly into the collection containers 14 that are arranged to the side adjacent to the gap 7.

(22) FIG. 4A shows the machine tool 1 of FIG. 1 without the front part of the machine frame 5, in which the frame interior 6 with the gap 7 is easily visible. As may be identified in FIG. 4A, and in particular in FIG. 4B, the stamping die 9b has a continuous die opening 29, scrap parts and/or splinters and optionally good parts being able to pass through the opening under the action of gravitational force during the processing of the workpiece 2. Below the stamping die 9b a splinter pipe 30 is attached to a machine part (stamping support) of the spindle nut of the lower drive spindle 11b that may be moved together with the stamping die 9b in the gap 7, the splinter pipe adjoining the die opening 29 and forming a part of a (further) receiving device 12a for workpiece parts 2a to be ejected through the die opening 29 (scrap and optionally good parts).

(23) The (further) receiving device 12a has an ejection device 15a with a flap 17a that may be pivoted from a first horizontal pivoted position S1 shown in FIG. 4b in which the flap 17a closes the lower end of the splinter pipe 30 by means of an actuator 19a, which in the example shown is configured as a pneumatic cylinder, from the first pivoted position S1 into the second pivoted position S2 shown in FIG. 4A, in order to eject downwardly the workpiece parts 2a. As may be identified in FIG. 4A, a row of receiver containers 14a (boxes) is arranged below the flap 17a in the gap 7 to collect the workpiece parts 2a. The direction of the pivot axis 18a of the flap 17a is aligned parallel to the X-direction so that when opening the flap 17a the workpiece parts 2a are ejected to the side into the gap 7. To ensure that all of the workpiece parts 2a drop in the direction of the receiver containers 14a, a guide plate 31 is attached to the side of the machine part in the form of the stamping support at the height of the flap 17a.

(24) As illustrated in FIG. 4A, by using the control device 13 described above, by the opening and/or pivoting of the flap 17a an ejection of workpiece parts 2a into collection containers 14a arranged at different ejection positions Y.sub.A1, Y.sub.A2, Y.sub.A3 . . . inside the gap 7 may take place. For a standard emptying process, the stamping die 9b together with the receiving device 12a can be positioned at a tool changing position in the Y-direction, which for example is formed at the end of the movement path of the stamping die 9b along the lower drive spindle 11b shown in FIG. 4B. To permit an ejection that is as optimal as possible in terms of time, the emptying of the receiving device 12a and/or splinter pipe 30 takes place at the tool changing position or optionallywhen the splinter pipe 30 is fullin the next collection container 14a in the Y-direction, if the sorting of the workpiece parts 2a into different collection containers 14a is dispensed with.

(25) The collection containers 14a arranged in a row can be connected together via coupling elements so that they can be pulled together in the Y-direction out of the machine body 5. A different type of material and/or a different workpiece may be assigned to each of the collection containers 14a. For the sorting process, a suitable ejection position Y.sub.A1, Y.sub.A2, . . . Y.sub.A3 is approached in the Y-direction and by opening the flap 17a, the respective workpiece parts 2a that bear against the flap 17a of the collection device 12a are ejected and collected there. If workpiece parts 2a in the form of good parts are also ejected through the die opening 29, one or more of the collection containers 14a may be used for collecting and/or optionally for sorting good parts.

(26) The (further) receiving device 12a, in particular together with the receiving device 12 described in FIG. 1 to FIGS. 3A and 3B, may be used in the machine tool 1. In this case, a first row of collection containers 14 may be arranged adjacent to the gap 7 outside the machine frame 5 and a second row of collection containers 14a may be positioned inside the machine frame 5 in order to collect workpiece parts 2a received by the respective receiving device 12, 12a. However, optionally only the receiving device 12 described in FIG. 1 to FIGS. 3A and 3B or only the receiving device 12a described in FIGS. 4A and 4B, may be provided on the machine tool 1, in certain embodiments.

(27) In the machine tool 1 described above, the movement of the pressing tool 9 and/or the stamping die 9b in the gap 7 may be advantageously used in order to eject workpiece parts 2a at different ejection positions Y.sub.A1, . . . Y.sub.A3 so that the sorting of different workpiece parts 2a may already be undertaken in the machine tool 1. Instead of a pressing tool 9 with a stamping punch 9a and a stamping die 9b other pressing tools 9 may also be used in the machine tool 1, for example pressing tools 9, which have a bending punch and a bending die. As an alternative to the common mobility of the stamping die 9b and the receiving device 12, 12a in the gap 7, described above, it is also possible to move the receiving device 12, 12a independently of the stamping die 9b in the gap 7. The receiving device 12, 12a may be moved from a position adjacent to the stamping die 9b or optionally a position arranged below the stamping die 9b, in which these workpiece parts 2a are received, controlled and moved independently from the stamping die 9b at different ejection positions Y.sub.A1, . . . Y.sub.A3 along the gap 7. As soon as the workpiece parts 2a received in the receiving device 12, 12a, have been ejected at the ejection positions Y.sub.A1, . . . Y.sub.A3, the receiving device 12, 12a may be moved into a position adjacent to the stamping die 9b in the gap 7 in order to receive workpiece parts 2a once again.

OTHER EMBODIMENTS

(28) A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.