DEVICE FOR TRANSFER AND/OR HANDLING AND TRANSPORT OF WORKPIECES

Abstract

The invention relates to a device for handling and/or transporting workpieces (5), in particular for removal of injection-molded items from an injection-molding machine, wherein a handling robot (4) having a programmable control and regulating unit (10) is provided that comprises a gripper (6) having at least one suction nozzle (7) for grasping of the workpiece (5) or fixating it by suction. In the gripper (6) of the handling robot (4) a distance-measuring device (8) for detection of the distance (a.sub.1+a.sub.2) from the gripper (6) to a reference point or a reference surface (9), for example to the mold tool half (2), which is preferably movable, with the workpiece (5), is provided. The measured value of the distance-measuring device (8) is fed into the control and regulation unit (10). The distance-measuring device (8) can be a light-transit time measuring device, in particular a time-of-flight (TOF) sensor.

Claims

1. Device for handling and/or transporting workpieces, in particular for the removal of injection-molded items from an injection-molding machine, wherein a handling robot having a programmable control and regulating unit is provided that comprises a gripper having at least one suction nozzle for grasping of the workpiece or fixating it by suction, characterized in that in the gripper (6) of the handling robot (4) a distance-measuring device (8) for detection of the distance (a1+a2) from the gripper (6) to a reference point or a reference surface (9), for example to the mold half (2), which is preferably movable, with the workpiece (5), is provided, and that the measured value of the distance-measuring device (8) is fed into the control and regulation unit (10).

2. Device according to claim 1, characterized in that the distance-measuring device (8) is a light-transit time measuring device, in particular a time-of-flight (TOF) sensor.

3. Device according to claim 1, characterized in that the distance-measuring device (8) is a laser measurement device that measures according to the triangulation principle.

4. Device according to claim 1, characterized in that the connection from the distance-measuring device (8) to the control and regulation unit (10) is a wireless data connection, wherein the sensor board of the TOF sensor is supplied with a battery.

5. Device according to claim 1, characterized in that the connection from the distance-measuring device (8) to the control and regulation unit (10) is a wireless data connection, wherein the sensor board of the TOF sensor is supplied based on energy harvesting or kinetic energy harvesting.

6. Method for handling and/or transporting workpieces, in particular for the removal of injection-molded items from an injection-molding machine, using a device according to claim 1, characterized in that when the gripper (6) approaches the workpiece (5), the distance-measuring device (8) is or has been activated, and the distance (a1, a2) and/or the path until the workpiece (5) is grasped or fixated by suction, respectively, is measured continuously or permanently, and the measured value is fed into the programmable control and regulating unit (10), and upon reaching an adjustable or determined distance (a2) and/or path, the forward movement of the handling robot (4), is stopped, preferably in a braking operation, and the workpiece (5) is fixated by the suction of the suction nozzle (7).

7. Method according to claim 6, characterized in that the forward movement or the braking operation takes place at a delayed speed up to the stop.

8. Method according to claim 6, characterized in that for programming the control and regulating unit (10) of the handling robot (4), the basic parameters, such as, for example, transfer distance or removal distance, opening path of the injection-molding machine are empirically determined and entered via a teaching method (teach-in) and for example size, shape, position and surface structure of the workpiece (5).

Description

[0024] The invention will be explained in more detail by reference to an embodiment, which is illustrated in the drawing.

[0025] Wherein:

[0026] FIG. 1 schematically shows a tool room of an injection-molding machine with the handling robot and

[0027] FIG. 2 is a diagram of the removal process of the handling robot.

[0028] According to FIG. 1, an injection-molding machine 1 with the open molding tool halves 2, 3 is shown. A handling robot 4 is moved into the open tool halves 2, 3 for the removal of a workpiece 5. The position A of the handling robot 4 is the entry into the open mold, wherein in position A the handling robot 4 has already reached the point for the release of the measurement onto the reference surface 9.

[0029] In position B, the handling robot 4 is in the area of the workpiece 5.

[0030] The handling robot 4 is movable with a motor that can be acted upon via a programmable control and regulation unit. The handling robot 4 is provided with a gripper 6 and at least one suction nozzle 7. In the handling robot 4, a programmable control and regulation unit 10, optionally with an independent sensor evaluation unit, is provided.

[0031] In the gripper 6 of the handling robot 4, a distance-measuring device 8, e.g. the TOF sensor, for detection of the distance a.sub.1+a.sub.2 from the gripper 6 to a reference point or a reference surface 9, for example to the mold tool half 2, which is preferably movable, with the workpiece 5, is provided. The measured value a.sub.1+a.sub.2, i.e. the distance from the reference surface 9 to the distance-measuring device 8 of the entering handling robot 4 in position A, is fed into the control and regulation unit 10.

[0032] The distance-measuring device 8 can be a light-transit time measuring device, in particular a time-of-flight (TOF) sensor.

[0033] An alternative solution would be to implement the distance measuring device 8 as a laser measurement device that measures according to the triangulation principle.

[0034] The connection from the distance measuring device 8 to the control and regulation unit 10 or the sensor evaluation unit is preferably a wireless data connection, wherein the sensor board of the TOF sensor is supplied with a battery. As an alternative, elegant solution, the connection from the distance measuring device 8 to the control and regulation unit 10 could be a wireless data connection, wherein the sensor board of the TOF sensor is supplied based on energy harvesting or kinetic energy harvesting.

[0035] When the gripper 6 approaches the workpiece 5, the suction nozzles 7 are activated. The closer the suction nozzles 7 approach the workpiece, the smaller the distance a.sub.1 becomes. This distance a.sub.1+a.sub.2 is continuously or permanently measured, and upon reaching an adjustable or determined threshold value of the distance a.sub.1, for example at the distance a.sub.2, the forward movement of the handling robot 4 is stopped, preferably in a braking operation. When the suction nozzles 7 touch the workpiece 5, the workpiece 5 is fixated by the suction of the nozzles 7.

[0036] The distance a.sub.1+a.sub.2 can be measured at an interval of 4 milliseconds. Here the measurement of the distance a.sub.1+a.sub.2 could be performed analogously, where this measured value is digitized for processing already in the sensor or in the control and regulation unit 10.

[0037] Of course, the forward movement or the braking operation after reaching the threshold value can be carried out at a delayed speed up to the stop.

[0038] For programming the control and regulating unit of the handling robot 4, the basic parameters, such as, for example, transfer distance or removal distance, opening path of the injection-molding machine are empirically determined and entered for the threshold value via a teaching method (teach-in) and size, shape, position and surface structure of the workpiece 5.

[0039] According to FIG. 2, in a diagram on the one handwith a continuous linethe path s of the handling robot 4 over time t, and on the otherwith a dotted linethe distance a over time is shown.

[0040] The diagram shows that in the entry phase A of the handling robot 4 in the mold opening, the distance-measuring device 8 starts measuring. In addition, the path is covered very quickly. In this area, the suction nozzles 7 are not yet activated, but are approaching the workpiece 5. Of course, the suction nozzles could be activated earlier as well.

[0041] In position A, the suction nozzles 7 are activated, the measurements begin, and the distance a.sub.1 approaches the selected target value a.sub.2. Preferably from the threshold value or at most from position A, the gripper 6 approaches the workpiece 5 at reduced speed.

[0042] Approximately in position B, the suction nozzles 7 or the gripper 6, respectively, further approach the workpiece 5, and the distance a.sub.2 is reached. If this value is used or defined as a threshold value, the braking operation of the handling robot 4 starts here. The negative pressure of the suction nozzles 7 can of course increase towards the removal process. Due to the delayed speed until it stops, gentle removal is ensured.