EP1615747A1

EP1615747A1 - Device for cleaning and/or deburring workpieces

Info

Publication number: EP1615747A1
Application number: EP04708714A
Authority: EP
Inventors: Jürgen BEYERER
Original assignee: Hottinger KG
Current assignee: Hottinger KG
Priority date: 2003-04-09
Filing date: 2004-02-06
Publication date: 2006-01-18
Also published as: WO2004091857A1

Abstract

The invention relates to a device for cleaning and/or deburring workpieces, especially cast parts, comprising a machining device (3) having at least one tool for removing superfluous material. The inventive device is characterized by a manipulator (5) for picking up and bringing the workpiece (1) into a machining position, whereby the tool can be displaced from an end position (7) reached at the end of machining to a starting position (8) to be occupied at the beginning of machining.

Description

"Device for cleaning and / or deburring workpieces"

The invention relates to a device for cleaning and / or deburring workpieces, in particular cast parts, with a processing device comprising at least one tool for removing excess material.

Devices for cleaning and / or deburring workpieces, in particular cast parts, but also cores from core shooting ranges, are known in practice insofar as excess material or burrs have previously been removed by hand, for example by means of hand grinders, which ultimately the processing device have formed. Deburring is complex, particularly for workpieces with discontinuous transitions, as is the case with crankshafts, for example. It is not uncommon for downstream processing stations to be cast in labor-intensive three-shift operation.

When removing molding material, for example when deburring, it is essential that the excess material is processed abrasively, taking into account the desired shape of the workpiece and the permissible tolerances. Apart from the enormous use of manpower, there is a risk of deburring by hand that the burrs are effectively removed, but that the workpiece is damaged in the process.

To automate the deburring process, robots could now be used, which would take the workpiece to be deburred to a grinding station, for example, and move it there in accordance with the design and the course of the burrs. Such a robot would have to be both path-controlled and force-controlled, namely on the one hand to feed the workpiece to the processing station and on the other hand to apply the pressure required for processing against the tool. The realization of a path- and force-controlled robot is extremely complex, not least due to the required sensors and controls, especially since conventional robots and manipulators work with location or path control on a regular basis. The robot moves to an embossed location and usually places the tool there or hands it over to another station. The Interaction of commercially available robots and manipulators with the processing stations required here allows automation of the deburring process only with great effort.

It has already been mentioned above that this is basically a matter of exempting molding material from workpieces. Consequently, the workpieces can be any cast parts, for example closed crankshafts. Cores cast in core shooters must also be regularly deburred. With regard to core shooting ranges and the associated technology, reference is only made to DE 31 48 461 C1 by way of example, according to which numerous manipulators, conveyors and further processing stations are already connected to the actual core shooting.

The present invention is therefore based on the object of designing and developing a device for cleaning and / or deburring workpieces, in particular cast parts but also shot cores, in such a way that an automatic removal of excess molding material is possible.

According to the invention, the above object is achieved by the features of patent claim 1. Thereafter, a generic device is characterized by a manipulator for gripping and moving the workpiece into a machining position, the tool being movable from an end position reached at the end of the machining operation, which also serves as a parking position, into a starting position to be assumed at the beginning of the machining operation.

According to the invention, it was first recognized that irrespective of the typical mode of operation of conventional robots or manipulators, the previously manual removal of excess material can also be automated, namely by using a manipulator for gripping and moving the workpiece into the machining station. The workpiece is not placed there or handed over to a processing robot. Rather, the workpiece is still held by the same manipulator, the tool being moved from an end position reached at the end of the machining operation, in which the tool is in the idle state, to a starting position to be taken at the beginning of the machining operation is moved. This movement can be enforced via the manipulator or can be implemented by a suitable drive within the processing device. In any case, it is essential that it is not the manipulator that moves the workpiece for processing, but rather that the movement of the tool is responsible for the processing, whereby in the course of the movement of the tool it moves from the forced position to the end position, whatever It must be ensured that the burr is removed to the desired extent when the end position of the tool is reached.

The manipulator (the terms manipulator and robot are to be equated here) is advantageously controlled away. This means that the manipulator travels an embossed path in the usual way and positions the workpiece to be machined at a predetermined location and holds it there. Rotational movements are easily possible. In any case, the manipulator works path-controlled. The processing device or the tool, on the other hand, operates in a force-controlled manner, namely with an impressed force which is to be applied with respect to the burr to be removed. It should be noted that the path of the manipulator and the force or function of the processing device are controlled and monitored via a process computer.

In concrete terms, in addition to the actual tool, the machining device comprises an adjusting mechanism which enables the tool to be moved - together with a tool holder and possibly with the drive of the tool. In this respect, the adjusting mechanism is responsible for ensuring that the tool can be moved from the end position reached at the end of the machining into the starting position to be assumed at the beginning of the machining.

In concrete terms, the adjusting mechanism could be designed purely mechanically. Hydraulic or pneumatic actuation is possible if the adjusting mechanism comprises a cylinder-piston arrangement as the drive unit, which then serves as a drive for positioning, guiding and relocating the tool or the entire machining device. For example, the cylinder-piston arrangement could only be used to apply force to the tool and a separate — for example mechanical — actuating mechanism could be provided. Arbitrary realizations are possible, whereby it is essential here that the tool can be moved or displaced between the two positions, namely force-controlled.

In this way, the processing station can be actively designed to the extent that the tool can be moved or displaced by deliberately actuating the adjusting mechanism. The approach of the workpiece could preferably be detected contactlessly by means of suitable detectors, as a result of which the actuating mechanism is actuated via the process computer. The starting position can thus be approached, preferably depending on the specifically detected burr on the workpiece.

In a particularly advantageous and structurally simple manner, the tool can be brought into the starting position by mechanical action of the workpiece on the tool, preferably via the adjusting mechanism provided there. This could work in such a way that when the workpiece held by the manipulator approaches it hits the tool in the end position and pushes it back against the force of the adjusting mechanism until the starting position for machining is reached. The path covered corresponds exactly to the burr to be removed. After calibration of the manipulator and the machining device, both the workpiece and the tool, including the respective function, can be monitored optically. This will be discussed later.

In any case, it is advantageous if the tool can be brought into the starting position against a specifiable holding force of the adjusting mechanism of the processing device. The holding force can be generated via the previously mentioned cylinder-piston arrangement of the adjusting mechanism. For example, the entire machining device could be brought into the starting position with or without the workpiece - due to its own drive.

At this point it should be noted once again that the manipulator holding the workpiece to be machined works exclusively location-controlled, namely on the basis of a path / location impressed on it. The processing device and thus the tool work under force control, namely with a predetermined force or Voltage against the burr to be removed. A simple and conventional control / regulation via a suitable processor is therefore possible.

In order to avoid unnecessary soiling, but in particular to avoid damage due to dirt and / or external influences, it is advantageous if the machining device with the essential parts thereof, with the exception of an effective area of the tool, is arranged in a housing. The machining device could be designed in such a way that only the tool itself moves relative to the workpiece held by the manipulator. With regard to the deburring of workpieces, the tool could be a grinding wheel, brushes or the like. In particular when deburring crankshafts, it is advisable that, depending on the specific configuration of the crankshaft, a plurality of grinding wheels are provided next to one another, with a predetermined distance from one another and with a corresponding dimensioning of the grinding wheel. Optimal adaptation to the crankshaft to be deburred is an advantage.

It has already been mentioned before that the control or regulation of the entire machining can be carried out on the basis of the result of a visual inspection, both the workpiece and the tool being able to be checked or detected.

First of all, a visual inspection device for workpiece inspection could be provided, according to which the burrs or the like to be removed and their exact position and dimensioning on the workpiece can be determined. This makes it possible to coordinate the actual machining with the workpiece.

The visual inspection device is also readily suitable for detecting damaged areas on the workpiece. A target / actual comparison is possible via the process computer, so that defective parts can be identified and separated out.

The visual inspection device comprises at least one camera and could work according to the silhouette inspection system, namely it could capture the contours of the respective workpiece. Any visual inspection principles can be implemented. With The data determined by the visual inspection device are fed to the process computer in a further advantageous manner and are used there to control the manipulator and / or the processing device. To this extent, processing can be optimized.

In addition or as an alternative to the visual inspection of the workpiece, it is advantageous if the tool is also inspected. It must be taken into account that the tool, for example a grinding wheel, is subject to constant wear. Damage to the tool cannot be ruled out either. Accordingly, a preferably optically working tool testing device is provided, in particular for the determination of wear and defects on the tool. The tool testing device advantageously comprises a light source and a camera, the light source and camera being able to be arranged in a test head while forming a test field. The test head can be partially positioned around the tool in such a way that the tool or at least parts of the tool are located in the beam path between the light source and the camera. The test head is handled by a manipulator, whereby the test can take place in a definable cycle between the respective processes.

Here, too, the data from the tool test are fed to the process computer, which can be used to control both the manipulator and the machining device. To this extent, the data from the tool test could be used to position or calibrate the tool and / or the workpiece. This is particularly advantageous when the grinding wheel is exposed to constant wear, so that constant recalibration ensures clean deburring.

The tool position can be calibrated using the adjusting mechanism of the machining device. The machining position of the manipulator can also be changed or calibrated in accordance with the data from the tool test. Overall, the operating parameters of the machining device and / or are in accordance with the data of the workpiece test and / or the tool test of the manipulator can be controlled or regulated, whereby a continuous optimization of the processing is possible.

It is also possible to take casting tolerances into account, namely by detecting them. The tool drive could be switched off. The workpiece to be deburred is placed on a burr-free point, i.e. scanned in an area where no burrs can occur to measure the current dimension of the workpiece within the casting tolerance. This measurement can be taken into account in the subsequent processing, so that casting tolerances can be taken into account and quasi automatically compensated for.

It is also possible to detect the deflection of the tool via a path measuring system, specifically over the course of time. The time course of the deflection can be mathematically evaluated in a process computer, for example in order to detect inadmissible burrs or other defects that can lead to the workpiece being ejected, for example for special treatment. Links to downstream or parallel processing stations are possible.

There are now various possibilities for advantageously designing and developing the teaching of the present invention. For this purpose, reference is made on the one hand to the claims subordinate to claim 1 and on the other hand to the following explanation of a preferred embodiment of the invention with reference to the drawing. In connection with the explanation of the preferred exemplary embodiment of the invention with reference to the drawing, generally preferred refinements and developments of the teaching are also explained. Show in the drawing

Fig. 1 in a schematic view, in the form of a rough sketch

Embodiment of a device according to the invention for cleaning and / or deburring workpieces, a grinding wheel being indicated as a tool and Fig. 2 is a schematic view of the basic structure of a visual inspection device that can be used on the one hand for visual inspection of the workpiece to be machined and on the other hand for visual inspection of the tool.

1 schematically shows a device for deburring workpieces, the workpiece 1 and the burr 2 to be removed there being indicated only schematically. In any case, the workpiece 1 is a cast part, for example a crankshaft. The ridge 2 extends over an area of the workpiece 1 and is shown here together with the workpiece 1 in section.

The device comprises a processing device 3, to which a tool belongs. The tool here is specifically a grinding wheel 4 which is driven in rotation. The excess material or the burr 2 on the workpiece 1 is removed by means of the grinding wheel 4.

According to the invention, a manipulator 5 is used for gripping and moving the workpiece 1 into a machining position, which is only indicated by an arrow 6 in FIG. 1, the grinding wheel 4 moving from a front end position 7 reached at the end of the machining into a rear starting position 8 to be assumed at the beginning of the machining is movable.

The manipulator 5 is path-controlled and the processing device 3 or the grinding wheel 4 is force-controlled. For this purpose, the processing device 3 comprises an adjusting mechanism 9, which is only indicated in FIG. 1. A cylinder-piston arrangement 10 serves to apply force to the grinding wheel 4 with respect to the workpiece 1. The drive 11 of the grinding wheel 4 is only indicated.

At this point it should be noted that the adjusting mechanism 9 and the cylinder-piston arrangement 10 can be combined, so that both the positionability of the grinding wheel 4 and the required force can be generated via the cylinder-piston arrangement 10. The distance traveled 12 can be determined by means of suitable detectors and fed to a process computer 13, so that pressure control via the cylinder-piston arrangement 10 is possible via the detected route.

In FIG. 1, reference numeral 14 merely indicates that a visual inspection device 14 can be provided for the visual inspection of the grinding wheel 4 and / or the workpiece 1, which can be used, for example, between predeterminable working cycles via a separate manipulator, not shown in the figures.

2 shows the basic structure of such a visual inspection device 14, which comprises a camera 15 and - if necessary - a light source 16. The visual inspection device 14 or camera 15 and light source 16 of the visual inspection device 14 are arranged in a test head 17, only indicated in FIG. 2, which spans a test field 18. During the test, the test head 17 is to be arranged around the grinding wheel 4 or the workpiece 1 such that the area to be tested is in the test field 18.

To avoid repetition, reference is made to the general part of the description with regard to further advantageous refinements, which are not shown in the figures.

Finally, it should be noted that the exemplary embodiment discussed above serves the exemplary description of the claimed teaching, but does not restrict it to the exemplary embodiment.

Claims

Patent claims

1. Device for cleaning and / or deburring workpieces, in particular cast parts, with a processing device (3) comprising at least one tool for removing excess material, characterized by a manipulator (5) for gripping and moving the workpiece (1) into a processing position, the tool being movable from an end position (7) reached at the end of the machining into a starting position (8) to be assumed at the beginning of the machining.

2. Device according to claim 1, characterized in that the manipulator (5) is path-controlled and the processing device (3) or the tool is force-controlled.

3. Device according to claim 1 or 2, characterized in that the processing device (3) comprises an adjusting mechanism (9) which enables movement of the tool together with a tool holder and optionally with a drive (11).

4. The device according to claim 3, characterized in that the adjusting mechanism (9) comprises a cylinder-piston arrangement (10) which serves as a drive for positioning, guiding and relocating the tool.

5. The device according to claim 3 or 4, characterized in that the tool is movable or displaceable by actuating the actuating mechanism (9).

6. The device according to claim 3 or 4, characterized in that the tool can be moved into the starting position (8) by mechanical action of the workpiece (1) on the tool, preferably via the adjusting mechanism (9).

7. Device according to one of claims 3 to 6, characterized in that the tool can be brought into the starting position (8) against a predetermined holding force of the adjusting mechanism (9).

8. The device according to claim 7, characterized in that the holding force can be generated via the cylinder-piston arrangement (10).

9. Device according to one of claims 1 to 8, characterized in that the entire machining device (3) under the action or without action of the workpiece (1) can be moved into the starting position (8).

10. Device according to one of claims 1 to 9, characterized in that the processing device (3) with the essential parts thereof, with the exception of an effective range of the tool, is arranged in a housing.

11. The device according to one of claims 1 to 10, characterized in that the tool is designed as a grinding wheel (4).

12. The apparatus according to claim 11, characterized in that a plurality of grinding wheels are arranged side by side and at a predetermined distance from each other.

13. Device according to one of claims 1 to 12, characterized in that a visual inspection device (14) is provided for workpiece inspection, with which the burrs to be removed (2) or the like and their exact position and dimension on the workpiece (1) can be determined.

14. The apparatus according to claim 13, characterized in that the visual inspection device (14) for the detection of damaged areas on the workpiece (1), preferably by target-actual comparison.

15. The apparatus of claim 13 or 14, characterized in that the visual inspection device (14) comprises at least one camera (15).

16. The apparatus according to claim 15, characterized in that the visual inspection device (14) worked according to the silhouette inspection system.

17. Device according to one of claims 13 to 16, characterized in that the data determined with the visual inspection device (14) can be fed to a process computer (13) for controlling the manipulator (5) and / or the processing device (3).

18. Device according to one of claims 1 to 17, characterized in that a preferably optically working tool testing device is provided for testing the tool (4), in particular for determining wear or defects.

19. The apparatus according to claim 18, characterized in that the tool testing device comprises a light source (16) and a camera (15).

20. The apparatus according to claim 19, characterized in that the light source

(16) and the camera (15) are arranged to form a test field (18) in a test head (17).

21. The apparatus according to claim 20, characterized in that the test head

(17) can be positioned at least partially around the tool such that the tool is located in the beam path between the light source (16) and the camera (15).

22. The apparatus according to claim 21, characterized in that the test head (17) can be handled via a manipulator (5).

23. Device according to one of claims 18 to 22, characterized in that the data of the tool test can be fed to a process computer (13) which serves to control the manipulator (5) and / or the machining device.

24. Device according to one of claims 18 to 23, characterized in that the data of the tool test serve for positioning or calibration of the tool and / or the workpiece (1).

25. The device according to claim 24, characterized in that the calibration of the tool position via the adjusting mechanism (9) of the processing device (3).

26. Device according to one of claims 18 to 25, characterized in that the machining position of the manipulator (5) can be calibrated in accordance with the data of the tool test.

27. The device according to one of claims 18 to 26, characterized in that the operating parameters of the machining device (3) and / or the manipulator (5) can be controlled or regulated in accordance with the data of the workpiece test and / or the tool test.