METHOD FOR ARRANGING SEMIFINISHED PRODUCTS

Abstract

A method of arranging, in particular thermoplastic, semi-finished products by using an electronically controlled or regulated placing device for the semi-finished products. The method includes detecting at least one part of an outline of a semi-finished product to be placed, wherein the detecting is carried out by a detection device, determining a target position for the semi-finished product and/or for the placing device for placing the semi-finished product by matching the at least one part of the outline with a placing edge occurring on an underlying surface, and placing the semi-finished product by the placing device using the target position.

Claims

1. A method of arranging, in particular thermoplastic, semi-finished products by using an electronically controlled or regulated placing device for the semi-finished products, the comprising: detecting of at least one part of an outline of a semi-finished product to be placed, wherein the detecting is carried out by a detection device, determining a target position for the semi-finished product and/or for the placing device for placing the semi-finished product by matching the at least one part of the outline with a placing edge occurring on an underlying surface and placing the semi-finished product by the placing device using the target position.

2. The method according to claim 1, wherein a flat semi-finished product with an upper side, a bottom side and lateral edges is used.

3. The method according to claim 2, wherein the detecting of the at least one part of the outline of the semi-finished product is carried out from a detection viewing direction which is oriented substantially rectangular to the upper side or to the bottom side.

4. The method according to claim 1, wherein the target position for the semi-finished product and/or for the placing device for placing the semi-finished product is determined in such a way that when placing the semi-finished product gaps are prevented between the semi-finished product and an already previously placed semi-finished product and/or an overlapping is prevented between the semi-finished product and an already previously placed semi-finished product.

5. The method according to claim 1, wherein prior to the detecting of the at least one part of the outline, the semi-finished product is picked up by the placing device, preferably from a picking table of a semi-finished products store.

6. The method according to claim 1, wherein the semi-finished product is held by the placing device when detecting the at least one part of the outline of the semi-finished product.

7. The method according to claim 1, wherein a comparison of the detected outline with a saved outline reference range and/or a comparison of a measurement of the semi-finished product determined from the detected outline with a saved reference measurement range is carried out, wherein depending on a result of this comparison either a sorting out of the semi-finished product is carried out when the detected outline of the semi-finished product lies at least in sections beyond the outline reference range or the measurement of the semi-finished product lies beyond the reference measurement range, or the semi-finished product is made available for the use in a molding process when the determined outline of the semi-finished product lies within the outline reference range or the determined measurement of the semi-finished product lies within the reference measurement range.

8. The method according to claim 1, wherein a semi-finished product is used which comprises reinforcement fibers, wherein the running direction of the reinforcement fibers is detected by the detection device, and the semi-finished product is sorted out when the detection device detects that the gaps between the reinforcement fibers are too large.

9. The method according to claim 1, wherein a detection device for detecting the at least one part of the outline is used, wherein the outline is detected relative to at least one reference mark, preferably formed on the placing device.

10. The method according to claim 1, wherein the placing device comprises a handling device.

11. The method according to claim 1, wherein a position and/or an orientation of the semi-finished product, preferably relative to a reference mark formed on the placing device, are/is determined from the detected outline.

12. The method according to claim 11, wherein the target position for the semi-finished product and/or for the placing device are/is determined from the position and/or the orientation of the semi-finished product.

13. The method according to claim 1, wherein the detection device comprises an optical measuring system, in particular a camera.

14. The method according to claim 13, wherein the detection device comprises an illumination device, wherein an illumination device is used, where a spectral distribution of the emitted electromagnetic radiation is adapted to an absorption spectrum of the semi-finished product in such a way that a contrast ratio of the images captured by the optical measuring system is optimized.

15. The method according to claim 1, wherein during the detection of at least one part of the outline, the semi-finished product is pressed against a detection surfacepreferably formed as a plate, which plate is preferably at least partially transparent for the optical measuring systemof the detection device.

16. The method according to claim 1, wherein the placing device comprises a placing surfacepreferably formed on a placing tablefor the semi-finished product, wherein the placing surface forms the underlying surface for placing the semi-finished product.

17. The method according to claim 15, wherein the detection surface of the detection device is formed separate from the placing surface of the placing device and is arranged distanced to the placing surface.

18. A molding process for the production of a molding part in a molding installation, wherein the molding installation comprises a molding machine, in particular an injection molding machine, and a placing device, the process comprising: carrying out the method according to claim 1, inserting at least one semi-finished product, which has been made available for use, into a molding tool of the molding machine, closing the molding tool, whereby the at least one semi-finished product is at least partially situated in a cavity of the molding tool, introducing a liquid molding material, in particular a plastic melt, into the cavity, at least partially hardening of the introduced liquid molding material together with the at least one semi-finished product to form the molding part, opening of the molding tool and removing the molding part from the molding tool.

19. A device for arranging, in particular thermoplastic, semi-finished products, comprising a placing device for the semi-finished products, which can be controlled or regulated by an electronic controlling or regulating unit, and a detection device, which is configured to detect at least one part of an outline of a semi-finished product to be placed, wherein the controlling or regulating unit is configured to determine a target position for the semi-finished product and/or for the placing device by matching the at least one part of the outline with a placing edge occurring on an underlying surface and to use the target position when controlling or regulating the device for placing the semi-finished product.

20. The device according to claim 19, wherein the matching can be carried out by minimizing the gaps between the semi-finished products or a defined extent of a gap or of an overlap can be provided.

21. The device according to claim 19, wherein the placing device comprises a handling device for handling, preferably picking up, transporting and placing, the semi-finished product.

22. The device according to claim 19, wherein a reference mark is provided on the placing device, wherein the outline, the position and/or the orientation of the semi-finished product can be detected or can be determined relative to the reference mark.

23. The device according to claim 19, wherein the controlling or regulating unit is configured to carry out a comparison of the detected outline with a saved outline reference range and/or a comparison of a measurement of the semi-finished product determined from the detected outline with a saved reference measurement range, and, depending on a result of this comparison, either to move the semi-finished product by the placing device into a sorting-out area when the detected outline of the semi-finished product lies at least in sections beyond the outline reference range or the measurement of the semi-finished product lies beyond the reference measurement range, or to move the semi-finished product by the placing device into a making-available area when the determined outline of the semi-finished product lies within the outline reference range or the determined measurement of the semi-finished product lies within the reference measurement range.

24. The device according to claim 23, wherein the outline reference range is saved in a memory of the controlling or regulating unit.

25. A molding installation for producing a molding part, comprising a molding machine, in particular an injection molding machine, and the device according to claim 19.

26. The molding installation according to claim 25, comprising an installation control unit, wherein the controlling or regulating unit of the device for arranging semi-finished products is connected by signaling technique with the installation control unit or is integrated into the installation control unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Further details and advantages of the present invention are described more fully hereinafter by means of the specific description with reference to the embodiments illustrated in the drawings, in which:

[0075] FIG. 1 is a perspective view of a semi-finished product,

[0076] FIG. 2 is a top view onto the semi-finished product, whereby the outline is apparent,

[0077] FIG. 3 is a top view onto a semi-finished product in the form of a woven fabric,

[0078] FIG. 4 is a top view onto a molding part,

[0079] FIG. 5 is a cross section through a semi-finished product lay-up according to the state or the art with undesired overlappings,

[0080] FIG. 6 is a cross section through a semi-finished product lay-up according to the state of the art with undesired gaps,

[0081] FIG. 7 is a schematic view of a device for arranging semi-finished products for a molding process,

[0082] FIG. 8 is a schematic top view of a semi-finished product with unsuitable lateral edges,

[0083] FIG. 9 is a schematic top view of a semi-finished product with appropriate lateral edges,

[0084] FIG. 10 is a schematic view of a molding installation, and

[0085] FIG. 11 is a perspective view of the device for preparing semi-finished products with a picking table, a camera table and a placing table.

DETAILED DESCRIPTION OF THE INVENTION

[0086] FIG. 1 is a perspective view of a flat semi-finished product H. This semi-finished product H comprises an upper side O1 as well as a bottom side O2. The circumferential borders of this semi-finished product H are formed by the lateral edges S1, S2, S3 and S4.

[0087] When looking from above (corresponds to the detection viewing direction B) onto this semi-finished product H, the outline U is visible, as for example shown in FIG. 2. This outline U of the semi-finished product H is assembled by the four lateral edges S1 to S4.

[0088] FIG. 3 shows a top view onto a flatly formed semi-finished product H. In this case, the semi-finished product H is formed as a woven fabric and consists of a plurality of reinforcement fibers V. These reinforcement fibers V are grouped in longitudinal fibers V.sub.L which are oriented parallel to each other and in transverse fibers V.sub.Q which are oriented rectangular to the longitudinal fibers V.sub.L. Of course, the individual fibers V can also be arranged in other forms than shown in FIG. 3. The reinforcement fibers V can also pre-impregnated.

[0089] FIG. 4 shows a molding part F which is produced in a molding process. This molding part F comprises on the one hand the reinforcement fibers V and on the other hand the initially liquid and the hardened molding material K. In the shown embodiment, the reinforcement fiber V is arranged in serpentines. Such a molding part F forms a fiber-reinforced plastic which is especially used in lightweight construction.

[0090] However, mostly not only one semi-finished product H is used for the production of fiber-reinforced plastic, but a plurality of semi-finished products H are placed in a determined arrangement adjacent to each other and/or above each other. Thereafter, this plurality of semi-finished products H is overmolded by the liquid molding material K. This arranging of semi-finished products H is also known as a semi-finished products lay-up.

[0091] As shown in FIG. 5, undesired overlappings (see encircled area) can occur when placing several semi-finished products H. Because of such overlappings, the wall thickness of the semi-finished product lay-up can be increased locally by a multiple. Subsequently, this can lead to problems during the consolidation of the semi-finished products H, as these overlappings are not considered during the consolidation. Thus, a massive pressure increase can occur locally, which leads to a fiber swimming during the consolidation. This, in turn, has a negative influence on the mechanic characteristics of the emerging molding part F and on the component made thereof, respectively.

[0092] FIG. 6 shows another negative case which was occurring during the production of molding parts F from semi-finished products H. In this case, the semi-finished products H are not placed edge to edge, whereby a gap emerges. In the better case, this gap is filled with polymer matrix. In a worse case, even an alley (or hole) without a polymer matrix or without a fiber, remains in the component. In both cases the mechanical characteristics are massively restricted.

[0093] A method and a device 7 according to the invention are provided in order to a priori exclude such cases.

[0094] FIG. 7 schematically shows a detection device 2 and a controlling or regulating unit 8. These two componentsin this case together with a placing device which comprises a handling device 3together form the device 7 for arranging semi-finished products H for a molding process. The handling device 3 comprises a socket 11, the handling arm 12 supported movably on the socket 11 and the transfer head 13. Holding elements 14 (e. g. in the form of vacuum suction cups) are arranged on the transfer head 13. A semi-finished product H can be picked up from the semi-finished product store 13 with such a holding element 14. At least one illumination device 16 and a recording device 17 (e. g. an optical measuring system, preferably a camera system) of the detection device 2 are arranged on the transfer head 13. The semi-finished product H is illuminated by the illumination device 16 in such a way that especially the outline U of the semi-finished product H can be visually detected by the recording device 17. The detection device 2 is signally connected to the controlling or regulating unit 8. An outline reference range Rpreferably adjustable by a useris saved in a memory 9 of the controlling or regulating unit 8. A signal Su representing the outline U is transmitted to the controlling or regulating unit 8 by the recording device 17 of the detection device 2. The outline U is compared with the outline reference range R in a comparing unit of the controlling or regulating unit 8. If the outline U is arranged at least partially beyond the outline reference range R, a signal S.sub.EX for sorting out the semi-finished product H is outputted. By means of the output of the signal S.sub.EX, the semi-finished product H is moved by the handling device 3 into the sorting-out area EX and is dropped therein. In contrast, is the outline U within the outline reference range R, a signal S.sub.OK for making available the semi-finished product H for a molding process is outputted. By means of the output of this signal S.sub.OK, the semi-finished product H is moved by the handling device 3 into the making-available area OK or directly to the placing table 6 and is placed thereon.

[0095] FIG. 8 schematically shows a recording area 18 of the detection device 2. After the flat semi-finished product H has been moved into this recording area 18, the outline U of this semi-finished product H it at least partially compared with the reference range R by the recording device 17. It schematically follows from this FIG. 8 that the right side edge or placing edge (corresponds to the lateral edge S4) of the outline U at least partially lies beyond the reference range R (which is freely selectable by a user). This reference range R can also be referred to as tolerance field.

[0096] FIG. 9, in contrast, shows a case in which the right lateral edge of the outline lies completely within the reference range R. A semi-finished product H which is formed in such a way, thus, can be further processed. FIG. 9 also shows that by means of the detection device 2 the position P and the orientation A of the semi-finished product H is detected relative to a reference point X fixed at the recording area 18. Corresponding signals can also be transmitted to the controlling or regulating unit 8. Depending on these signals, the semi-finished product H can then be positioned on the target position P.sub.SOLL accordingly.

[0097] On the basis of FIG. 10, finally, the molding process and the molding installation 4 is still schematically illustrated. This molding installation 4 (also referred to a molding plant) comprises the molding machine 1 and at least the device 7 for arranging semi-finished products H for a molding process. The molding machine 1 comprises the injection unit 19 for injecting the liquid molding material K and the closing unit 20. The molding tool 5 is mounted to mold mounting plates of the closing unit 20. The molding mounting plates can be moved relative to each other by the drive device 21. In the closed state, the cavity C is formed between the mold halves of the molding tool 5. The placing device is formed by the placing table 6 together with the handling device 3. The placing table 6 comprises a plate which forms the placing surface. A plurality of semi-finished products H is placed on the placing table 6 (or optionally onto a placing surface directly formed in the molding tool 5) by the handling device 3. The semi-finished products H are positioned on a target position P.sub.SOLL. Preferably, the target position P.sub.SOLL is saved or is determined by the installation control unit 10. The semi-finished products H can be held, preferably over the entire surface, on a plate of the placing table 6 by a vacuum generating device (not shown). The semi-finished products H are thenfor example as a semi-finished product cluster (if the individual semi-finished products H are already connected to each other e. g. by bonding or welding) or together with the placing table 6 formed as a sliding tablemoved into the molding tool 5, whereby the semi-finished products H are located in the cavity C. Subsequently to the closing of the molding tool 5, liquid molding material K (in particular plastic melt) is introduced into the cavity C. The consolidation of the molding material K together with the semi-finished product H to form the molding part F is carried out by a corresponding pressure application by means of the closing unit 20. The hardening can still be accelerated by a cooling. After opening the molding tool 5, the molding part F can be removed by the handling device 3 (or by an ejection device). In this schematical example according to FIG. 10, the controlling or regulating unit 8 is an integral component of the installation control unit 10. All substantial components of the molding installation 4 are centrally controlled or regulated with this installation control unit 10.

[0098] Especially the step of the detection of the (partial) outline U of the semi-finished product H is shown with reference to FIG. 11.

[0099] FIG. 11 shows a semi-finished product store 15. A plurality of (already cut) semi-finished products H is stored in the semi-finished product store 15. Basically, it is possible that the handling device 3 of the placing devices picks up each semi-finished product H directly from the semi-finished product store 15. For a faster process, however, it is provided that this semi-finished product store 15 comprises a separating device 23 with which individual semi-finished products H can be retrieved from the magazine compartment and can be made available for the picking up on the picking surface of the picking table 22.

[0100] Subsequently, the semi-finished product H made available on the picking table 22 is picked up by the transfer head 13 of the handling device 3 and is transported to the detection device 2. At this point, the semi-finished product H is only broadly centered so that the picking-up position of the semi-finished product H (tape) on the transfer head 13 can slightly vary.

[0101] The detection device 2 comprises the detection surface E. In this case, the detection surface E is formed on a transparent plate 24. A recording device 17 (not shown here) is arranged below the transparent plate 24. The recording device 17 is formed as a camera of an optical measuring system which is directed towards the transparent plate 24. The detection surface E of the transparent plate 24 together with the camera forms the so-called camera table.

[0102] As the semi-finished product H is held only punctually by means of a vacuum on the transfer head 13, it cannot be guaranteed that the true dimensions of the semi-finished product H on the transfer head 13 can be measured. In order to bring the semi-finished product H into a stretched position, the transfer head 13 is pressed against the detection surface E. Thus, the semi-finished product H is automatically brought into a stretched position. As the detection surface E is stationary, subsequently also the distance between the semi-finished product H and the optical measuring system is defined and is predetermined. Thereby, a simple and constant detection can be carried out, especially as most optical measuring systems work with a fix focal length.

[0103] As soon as the semi-finished product H has reached the stretched position, the optical measuring system of the detection device 2 captures an image of the semi-finished product H together with the transfer head 13 through the transparent plate 24. In order to determine the exact location of the semi-finished product H at the transfer head 13, a reference point or mark X is located at the transfer head 13. The location and the size of this at least one reference mark X are known. Thus, it is possible to detect the exact location and/or orientation of the semi-finished product H in relation to the reference mark X. Especially, however, at least one part of an outline U of a semi-finished product H arranged on the detection surface E is detected by the detection device 2. This (partial) outline U is saved in a memory (or in the cloud) as after the placing this (partial) outline U forms a placing edge for a further semi-finished product H to be placed adjacent.

[0104] After the exact position of the semi-finished product H at the transfer head 13 of the handling device 3 is known, the transfer head 13 can be moved further to the placing surface L. This placing surface L is formed on a placing table 6. As a target position P.sub.SOLL for the semi-finished product H and/or for the placing device is determined by the controlling or regulating unit 8 by matching the at least one part of the outline U with a placing edge occurring on an underlying surface, the semi-finished product H can be placed by the placing device on the placing surface L using the target position P.sub.SOLL. The calculation of the exact position does not have to be carried out on the camera table, rather this calculation can also be carried out during the robot movement between the camera table and the placing table 6.

[0105] As soon as the transfer head 13 has reached the placing table 6, the semi-finished product H is taken over by the placing table 6. If the just placed semi-finished product H is the first layer which is placed, this semi-finished product H is fixed to the placing table 6 (preferably by means of a vacuum). At least one part of the saved outline U of the just placed semi-finished product H is then forming the placing edge occurring on the underlying surface (placing surface L) for a further semi-finished product H to be placed.

[0106] After the semi-finished product H is placed, the process again starts from the beginning and the transfer head 13 picks up the next semi-finished product H from the semi-finished product store 15 until the build-up of the whole semi-finished product lay-up is finished. The next placed semi-finished products H are then, preferably cohesively, connected to the adjacent located and/or below located semi-finished products, for example by several welding points.

[0107] FIG. 11 shows particularly well that the detection surface E of the detection device 2 is formed separate from the placing surface L of the placing device and is arranged distanced to the placing surface L. As a consequence, the outline detection and the placing can be decoupled or separated from each other. Thus, a particularly fast production of a semi-finished product lay-up is possible, especially as the two handling devices 3 can work offset from one another at the production of a semi-finished product lay-up. This means, while one handling device 3 is moving the semi-finished product H from the detection surface E to the placing surface L, the other handling device 3 can already move a semi-finished product H from the picking table 22 to the detection surface E.

LIST OF REFERENCE SIGNS

[0108] 1 molding machine [0109] 2 detection device [0110] 3 handling device [0111] 4 molding installation [0112] 5 molding tool [0113] 6 placing table [0114] 7 device for arranging semi-finished products [0115] 8 controlling or regulating unit [0116] 9 memory [0117] 10 installation control unit [0118] 11 socket [0119] 12 handling arm [0120] 13 transfer head [0121] 14 holding elements [0122] 15 semi-finished product store [0123] 16 illumination device [0124] 17 recording device [0125] 18 recording area [0126] 19 injection unit [0127] 20 closing unit [0128] 21 drive device [0129] 22 picking table [0130] 23 separating device [0131] 24 transparent plate [0132] H semi-finished product [0133] H1 first semi-finished product [0134] H2 second semi-finished product [0135] U outline [0136] R outline reference range [0137] O1 upper side [0138] O2 bottom side [0139] S1-S4 lateral edges [0140] B detection viewing direction [0141] X reference mark [0142] P position [0143] A orientation [0144] V reinforcement fibers [0145] F molding part [0146] C cavity [0147] K liquid molding material [0148] P.sub.SOLL target position [0149] EX sorting-out area [0150] OK making-available area [0151] S.sub.EX signal for sorting out the semi-finished product [0152] S.sub.OK signal for making available the semi-finished product [0153] V.sub.L longitudinal fibers [0154] V.sub.Q transverse fibers [0155] E detection surface [0156] L placing surface