Patent Application
20230249422
The invention relates to a device for processing fiber-reinforced reinforced plastic, according to the preamble of claim 1, to a device for processing layer constructions, according to the preamble of claim 13, to the use of a device of this type, according to claim 14, and to a method for controlling a device of this type, according to claim 15.
The use of fiber-reinforced plastics nowadays is rapidly increasing. This applies in particular to glass fiber-reinforced and carbon fiber-reinforced plastics, the use of the latter increasing by virtue of the ever increasing demand for lightweight construction solutions. This applies in particular to the aerospace industry and to the automotive industry.
However, the automated production of glass fiber-reinforced and carbon fiber-reinforced components (GFRP and CFRP components) still represents a major challenge. Manual processing thus still occupies a large proportion of the production.
In the known device for processing fiber-reinforced plastic (DE 10 2014 002 950 A1), from which the invention proceeds, various functional operations for treating a web of a fiber scrim of fiber-reinforced plastic are bundled in one device. The web is conveyed through the device by a single drive. As a result of a single drive being used, tensions and at worst distortions in the fiber scrim web may arise.
The invention is based on the object of designing and refining the known device in such a manner that the drive concept of said device is improved, in particular so as to achieve more uniform conveying of the fiber scrim web.
The above object in a device according to the preamble of claim 1 is achieved by the features of the characterizing part of claim 1.
Essential is the fundamental concept that a secondary drive which likewise drives the fiber scrim web can be provided besides the primary drive. If this secondary drive is combined with a force sensor, feedback-controlling of the secondary drive can be implemented, said feedback-controlling enabling stable and uniform conveying of the fiber scrim web even in the event of variations between the drives, such as can be created by manual interventions in the device, for example.
It is proposed in detail that the device has at least one secondary drive for driving the fiber scrim web; that the device has a force-measuring assembly, assigned to the secondary drive, having a force sensor for measuring a web tension of the fiber scrim web by means of the control assembly; that the control assembly actuates the secondary drive in a feedback-control routine; that the feedback-control routine comprises a secondary feedback-control loop for feedback-controlling the secondary drive; that the control assembly in the feedback-control routine feeds the web tension measured by the force-measuring assembly assigned to the secondary drive as an actual value to the secondary feedback-control loop and, based on the web tension in the secondary feedback-control loop, determines and sets a correcting variable, in particular the rotating speed or the torque, of the secondary drive.
In one design embodiment according to claim 2, the primary drive is likewise assigned a force sensor and a feedback-control loop which also feedback-controls the primary drive.
Provided in one preferred design embodiment according claim 3 is even at least one further secondary drive, which is likewise feedback-controlled. In this way, the web tension of the fiber scrim web can be further optimized by way of the device, in particular at critical locations in the processing of the fiber scrim web.
Claim 4 sets forth functional units which are preferably present. Claims 5 and 6 set forth preferred design embodiments of the fiber scrim web and the processing of the latter, in particular in terms of the connection of layers of the fiber scrim web. In the event of variations in the web tension, mutual delamination of the layers can arise in particular in the case of layer constructions from carbon fiber-reinforced plastics (CFRP) and glass fiber-reinforced plastic (GFRP), the layers thereof during processing usually being only partially connected to one another. This requires expensive manual rectification work or leads to rejects.
Preferred disposals of the drives are the subject matter of claim 7. Claim 8 sets forth preferred design embodiments of the drives, wherein in one particularly preferred design embodiment a drive roller of a drive has a casing of an elastic material, in particular a foam material, by means of which thickness fluctuations of the fiber scrim web can be compensated in a conveying direction as also in a direction transverse thereto. This also leads to a more uniform distribution of forces within the fiber scrim web.
Claim 9 relates to the disposal of the force sensor in relation to the assigned drive. The force sensor here is preferably disposed close to the drive, so as to be behind the drive.
Claims 10 and 11 relate to particularly preferred design embodiments of the force-measuring assembly. According to claim 10, the latter can have a deflection roller on which the fiber scrim web is deflected. This deflection roller can be flexibly mounted. According to claim 11, the force sensor can measure a deflection of the deflection roller, said deflection being a function of the web tension. It is preferable here for only a single force sensor to be provided, the latter being disposed so as to be approximately central on the deflection roller. Owing to the relatively high stability, in particular in the case of carbon fiber-reinforced and glass fiber-reinforced plastic, a single force sensor may be sufficient for feedback-controlling the drive, without comparatively major variations arising transversely to the conveying direction of the fiber scrim web.
According to claim 12, the drives are preferably mutually synchronized in a superordinate synchronization routine, as a result of which the web tension can be uniformly feedback-controlled along the device.
According to a further teaching according to claim 13, which is of independent relevance, a device for processing layer constructions is claimed. It has been recognized here that the proposed force-measuring assembly can in principle also be relevant for other materials. The device here can otherwise be designed so as to be substantially similar to the device of the first teaching. Reference may be made to all explanations pertaining to the device of the first teaching.
According to a further teaching according to claim 14, which is likewise of independent relevance, the use of a device of the first or of the second teaching for processing fiber-reinforced plastic is claimed. Reference may be made to all explanations pertaining to the devices according to the proposal.
According to a further teaching according to claim 15, which is likewise of independent relevance, a method for controlling a device according to the proposal is claimed. Reference may be made to all explanations pertaining to the devices according to the proposal, and to the use of said devices.
The invention will be explained in more detail hereunder by means of a drawing which illustrates merely one exemplary embodiment. In the drawing
The device 3 according to the proposal and illustrated in
The device 3 here has at least two functional units 4. One of these functional units 4 is an infeed unit 5 for feeding a fiber scrim web 6. The fiber scrim web 6 presently and preferably is composed of a fibrous material bonded with thermoplastics powder, and is thus composed of a fiber-matrix semifinished product which is also referred to as a prepreg. The fiber scrim web 6 presently and preferably is composed of a plurality of layers.
As is illustrated in
The functional units 4 furthermore comprise a processing unit 8 for processing the fiber scrim web 6. Examples of a processing unit 8 of this type will yet be mentioned hereunder. However, it is important here that this processing unit 8 acts on the fiber scrim web 6, the latter extending from the infeed unit 5 to the processing unit 8. The fiber scrim web 6 can also be cut in the further course of the device 3, but the cut parts of the fiber scrim web 6 in this instance are no longer part of the fiber scrim web 6. The fiber scrim web 6 is thus integral along a conveying direction F of the device 3.
The device 3 has a primary drive 9 for driving the fiber scrim web 6. The fiber scrim web 6 is pulled and/or pushed through the device 3 by means of this primary drive 9.
The device 3 furthermore has a control assembly 10 for controlling or feedback-controlling the primary drive 9.
It now is essential that the device 3 has at least one secondary drive 11 for driving the fiber scrim web 6. The secondary drive 11 in
It is furthermore essential that the device 3 has a force-measuring assembly 12, assigned to the secondary drive 11, having a force sensor 13 for measuring a web tension of the fiber scrim web 6 by means of the control assembly 10. In principle, the force sensor 13 can be an arbitrary force sensor 13. The preferred design embodiment of the force-measuring assembly 12 is yet to be explained hereunder. This force sensor 13 presently and preferably measures a force FB which is a function of the web tension.
It is likewise essential that the control assembly 10 actuates the secondary drive 11 in a feedback-control routine; that the feedback-control routine comprises a secondary feedback-control loop 14 for feedback-controlling the secondary drive 11; that the control assembly 10 in the feedback-control routine feeds the web tension measured by the force-measuring assembly 12 assigned to the secondary drive 11 as an actual value 15 to the secondary feedback-control loop 14 and, based on the web tension, determines and sets a correcting variable 16 of the secondary drive 11. The term “web tension” here is to be understood so broadly that the latter also comprises a force FB which is a function of the web tension. The web tension does not have to be actually calculated or determined in the strict sense.
The secondary feedback-control loop 14 is illustrated in
Presently and preferably, the web tension is feedback-controlled by way of the secondary drive 11. The correcting variable 16 of the secondary feedback-control loop 14 and/or of the secondary drive 11 presently and preferably is the motor current or the torque. Alternatively, the torque or the rotating speed of the secondary drive 11 can be feedback-controlled. In this case, it is thus provided that the control assembly 10 in the feedback-control routine feeds the web tension measured by the force-measuring assembly 12 assigned to the secondary drive 11 as an actual value 15 to the secondary feedback-control loop 14 and, based on the web tension, determines and sets the torque or the rotating speed of the secondary drive 11 as the correcting variable 16 of the latter.
Of course, further bifurcations of the secondary feedback-control loop 14, monitors and the like, are also possible.
Differing from what is illustrated, the control assembly 10 illustrated in
It can be provided that the device 3 has a further force-measuring assembly 12, assigned to the primary drive 9, having a force sensor 13 for measuring a web tension of the fiber scrim web 6 by means of the control assembly 10. The force-measuring assembly 12, which is assigned to the primary drive 9, is presently and preferably designed so as to be substantially identical to the force-measuring assembly 12 which is assigned to the secondary drive 11. All explanations pertaining to the force-measuring assembly 12, which is assigned to the secondary drive 11, may also apply to this force-measuring assembly 12 and to all further force-measuring assemblies 12 yet to be mentioned.
It can be provided that the control assembly 10 actuates the primary drive 9 in the feedback-control routine, and that the feedback-control routine comprises a primary feedback-control loop 22 for feedback-controlling the primary drive 9. All explanations pertaining to the secondary feedback-control loop 14 presently and preferably apply likewise to the primary feedback-control loop 22. For this reason, the feedback-control loop shown in
Accordingly, it is presently and preferably the case that the control assembly 10 in the feedback-control routine feeds the web tension measured by the force-measuring assembly 12 assigned to the primary drive 9 as an actual value 15 to the primary feedback-control loop 22 and, based on the web tension in the primary feedback-control loop 22, determines and sets a correcting variable 16 of the primary drive 9. It is even provided presently and preferably that the primary drive 9 and the secondary drive 11 are substantially identical and in terms of hierarchy are of equal standing.
The device 3 presently and preferably has at least one further secondary drive 11. The device 3 can have a further force-measuring assembly 12, assigned to the further secondary drive 11, having a force sensor 13 for measuring a web tension of the fiber scrim web 6 by means of the control assembly 10. It can be provided in this instance that the control assembly 10 actuates the further secondary drive 11 in the feedback-control routine; that the feedback-control routine comprises a further secondary feedback-control loop 14 for feedback-controlling the further secondary drive 11; that the control assembly 10 in the feedback-control routine feeds the web tension measured by the force-measuring assembly 12, assigned to the further secondary drive 11, as an actual value 15 to the further secondary feedback-control loop 14 and, based on the web tension in the further secondary feedback-control loop 14, determines and sets a correcting variable 16 of the further secondary drive 11. All explanations pertaining to the first secondary drive 11, to the assigned force-measuring assembly 12, and to the secondary feedback-control loop 14 apply here in an analogous manner. The device 3 preferably has two further secondary drives 11, preferably three further secondary drives 11, even furthermore preferably four further secondary drives 11, and/or at least two further secondary drives 11.
With a view to
The functional units 4 presently and preferably comprise a transverse forming unit 25 for forming the fiber scrim web 6 in a direction transverse to the conveying direction F. A transverse forming unit 25 of this type serves for establishing T-profiles and U-profiles, for example. Accordingly, the device 3 presently and preferably serves for producing T-profiles and/or U-profiles. Therefore, the preforms producible are presently and preferably T-profiles and/or U-profiles.
It can furthermore be provided that the functional units 4 comprise a cutting unit 26 for cutting the fiber scrim web 6. The fiber scrim web 6 ends after the cutting unit 26. It can furthermore be provided that the functional units 4 comprise a longitudinal forming unit 27 which serves for forming the fiber scrim web 6, or as is illustrated in
It is presently and preferably provided that the fiber scrim web 6 is a layer construction from at least two layers of fiber-reinforced plastic that are disposed on top of one another. The fiber-reinforced plastic presently and preferably is a carbon fiber-reinforced plastic (CFRP) or a glass fiber-reinforced plastic (GFRP).
As is likewise illustrated in
As has already been mentioned, the device 3 has a conveying direction F of the fiber scrim web 6. The second heating unit 30 presently and preferably is disposed behind the first heating unit 29 in the conveying direction F. It can be furthermore provided that the primary drive 9 and/or at least one secondary drive 11, along the conveying direction F, are/is disposed between the first and the second heating unit 29, 30.
The disposal of the drives 9, 11 in the device 3 is preferably chosen in such a manner that at least one functional unit 4, presently and preferably a processing unit 8, is disposed between the primary drive 9 and the secondary drive 11. Additionally or alternatively, it can be provided that at least one functional unit 4, presently and preferably a processing unit 8, is disposed between the secondary drive 11 and the further secondary drive 11. At least one functional unit 4, presently and preferably a processing unit 8, is in each case preferably disposed between the drives 9, 11.
Accordingly, the drives 9, 11 can be placed at critical locations within the device 3.
The schematic construction of the drives 9, 11 can be derived from
With a view to
The term “force sensor” here is to be broadly understood. Said force sensor may also comprise a plurality of sensors in the strict sense; it is important that the force sensor 13 measures the force at one location, as is illustrated. Force values thus cannot be measured at a plurality of mutually spaced-apart locations using one force sensor 13. The force sensor 13 presently and preferably comprises one or a plurality of piezo elements.
The force-measuring assembly 12 presently and preferably has a deflection roller 32 on which the fiber scrim web is deflected. The maximum deflection of the fiber scrim web 6, in particular in a layer construction, is preferably less than 90 degrees, furthermore preferably less than 60 degrees, even more preferably less than 45 degrees, yet more preferably less than 30 degrees, still furthermore preferably less than 20 degrees. It has been demonstrated that an intense deflection can lead to a delamination of the layers.
The deflection roller 32 presently and preferably is flexibly mounted. The deflection roller 32 presently and preferably is pivotably mounted. The deflection roller 32 here is mounted so as to be flexible in such a manner that a deflection of the deflection roller 32 is a function of the web tension. However, this deflection here is preferably less than 1 cm, furthermore preferably less than 1 mm.
As is illustrated in
Presently and preferably it is the case that the deflection roller 32 is flexibly mounted transversely to the conveying direction F on the two sides and, therefore, is deflectable in a mutually independent manner on both sides. As can be seen from
The force sensor 13 presently and preferably measures the deflection of the deflection roller 32. The force sensor 13 preferably engages on the deflection roller 32 on a side that faces away from the fiber scrim web 6. Alternatively, the fiber scrim web 6 can be disposed between the deflection roller 32 and the force sensor 13.
As illustrated, presently and preferably the force sensor does not engage directly on the deflection roller 32, but rather via a compression roller 32a.
The force sensor 13 presently and preferably engages transversely to the conveying direction F, in a range between 20% and 80% of the extent of the deflection roller 32 transverse to the conveying direction F. Furthermore preferably, the force sensor 13 engages in a range between 30% and 70% of the extent of the deflection roller 32 transverse to the conveying direction F, even furthermore preferably between 40% and 60% of the extent of the deflection roller 32 transverse to the conveying direction F. The force-measuring assembly 12 presently and preferably has exactly one force sensor 13 of this type, the latter potentially being correspondingly sufficient for measuring the web tension with adequate accuracy. This variant is preferable because a high level of stiffness in the direction transverse to the conveying direction F is provided in particular in the fiber-reinforced, preferably carbon fiber-reinforced plastics. This applies most particularly when the peripheries of the layers are already connected to one another. This one force sensor 13 presently and preferably engages so as to be substantially centric on the deflection roller 32.
It is presently and preferably provided for controlling the device 3 that the control assembly 10 synchronizes the drives 9, 11 in a superordinate synchronization routine. In the process, the command variables 17 of the feedback-control loops 14, 22 are preferably synchronized in the synchronization routine. As a result, homogenous controlling or feedback-controlling of the web tension can be achieved.
Proposed according to a further teaching, which is of independent relevance, is a device 3 for processing layer constructions, in particular for producing structural aircraft components 2 or preforms therefor. These layer constructions here can fundamentally comprise arbitrary materials. The materials presently and preferably are lightweight construction materials.
This device 3 here can be partially or completely designed like the device 3 previously described. This device 3 also has at least two functional units 4, the functional units 4 comprising at least one infeed unit 5 for feeding a layer web, and a processing unit 8 for processing the layer web. The device 3 furthermore has a primary drive 9 for driving the layer web, and a control assembly 10 for controlling or feedback-controlling the primary drive 9. The layer web is composed of at least two material layers, thus forming a layer construction. Said layer web is composed in particular of two layers of a lightweight construction material, preferably glass fiber-reinforced plastic or carbon fiber-reinforced plastic.
It is essential in this further device 3 that the device 3 has at least one secondary drive 11 for driving the layer web; that the device 3 has a force-measuring assembly 12, assigned to the secondary drive 11, having a force sensor 13 for measuring a web tension of the layer web by means of the control assembly 10; that the control assembly 10 actuates the secondary drive 11 in a feedback-control routine; that the feedback-control routine comprises a secondary feedback-control loop 14 for feedback-controlling the secondary drive 11; that the control assembly 10 in the feedback-control routine feeds the web tension measured by the force-measuring assembly 12 assigned to the secondary drive 11 as an actual value 15 to the secondary feedback-control loop 14 and, based on the web tension in the secondary feedback-control loop 14, determines and sets a correcting variable 16 of the secondary drive 11; that the force-measuring assembly 12 has a deflection roller 32 on which the layer web is deflected; that the deflection roller 32 is mounted so as to be flexible in such a manner that a deflection of the deflection roller 32 is a function of the web tension; and that the force sensor 13 measures the deflection of the deflection roller 32.
Reference may be made to all explanations pertaining to the device 3 according to the proposal of the first teaching.
It has been recognized here that the force-measuring assembly 12 according to the proposal is not only relevant for fiber-reinforced plastics. The control assembly 10 according to the proposal in this further teaching also is of high relevance.
Proposed according to a further teaching, which is likewise of independent relevance, is the use of a device 3 according to one of the first two teachings, for processing fiber-reinforced plastic, in particular carbon fiber-reinforced plastic or glass fiber-reinforced plastic, preferably for producing structural aircraft components 2 or preforms therefor. Reference may be made to all explanations pertaining to the devices 3 according to the proposal.
Proposed according to a further teaching, which is likewise of independent relevance, is a method for controlling a device 3 according to one of the first two teachings. It is essential here that the control assembly 10 carries out the feedback-control routine. Reference may be made to all explanations pertaining to the devices 3 according to the proposal and the use thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 114 894.1 | Jun 2020 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/056313 | 3/12/2021 | WO |
