Fibrous-preform conveying device

Abstract

The invention relates to a fibrous-preform conveying device for conveying fibrous preforms, wherein at least one contact roller which on its circumferential face displays an electrode and/or counter electrode is provided, such that an electric contact with the fibrous preform to be conveyed is achieved in order to initiate a current flow in the fibrous preform when the fibrous preform is conveyed in the conveying direction.

Claims

1. A fibrous-preform conveying device, comprising a material marshaling installation for marshaling fibrous preforms to be conveyed; a plurality of fibrous-preform contact rollers which include a plurality of electrodes and/or counter electrodes arranged on one or more circumferential faces of the contact rollers, wherein the circumferential faces are configured to bear on a fibrous preform to be conveyed; and an electrode control unit for successively applying an electric voltage to at least one of the electrodes and for switching a remainder of the electrodes and/or counter electrodes in such a manner that a current flow between a respective electrode and a predetermined counter electrode is initiated, wherein the plurality of electrodes are electrically isolated in relation to one another and to the counter electrodes, and wherein the plurality of electrodes and/or counter electrodes are connectable to an electric power source and the electrode control unit for applying an electric voltage, wherein the plurality of electrodes form an arrangement, and wherein the electrode control unit is configured to apply the electric voltage separately to each electrode or counter electrode in an individually defined manner using control patterns which lead to various current flows within the fibrous preform to be conveyed.

2. The fibrous-preform conveying device according to claim 1, wherein the plurality of fibrous-preform contact rollers includes a pair of fibrous-preform contact rollers having a first fibrous-preform contact roller which with part of its circumferential face bears on a first side of a fibrous preform to be conveyed, and having a second fibrous-preform contact roller which with part of its circumferential face bears on a second side, opposite the first side, of a fibrous preform to be conveyed, such that the fibrous preform to be conveyed is guided through between the first fibrous-preform contact roller and the second fibrous-preform contact roller.

3. The fibrous-preform conveying device according to claim 1, wherein the plurality of fibrous-preform contact rollers are spaced apart from one another.

4. The fibrous-preform conveying device according to claim 1, wherein each fibrous-preform contact roller has at least one electrode which, for initiating the current flow, interacts with a corresponding counter electrode.

5. The fibrous-preform conveying device according to claim 1, wherein a first number of fibrous-preform contact rollers have in each case at least one electrode and a second number of fibrous-preform contact rollers have in each case at least one counter electrode.

6. The fibrous-preform conveying device according claim 1, wherein the plurality of electrodes and/or counter electrodes are configured in the circumferential face so as to radially project in relation to at least one fibrous-preform contact roller.

7. The fibrous-preform conveying device according to claim 1, wherein at least one of the fibrous-preform contact rollers is configured for imposing a force in the direction of the fibrous preform to be conveyed.

8. The fibrous-preform conveying device according to claim 1, wherein at least one of fibrous-preform contact rollers displays a drive for conveying the fibrous preforms to be conveyed.

9. The fibrous-preform conveying device according to claim 1, further comprising a power regulating unit which depending on a conveying speed is equipped to regulate the electric power of the current flow initiated in the fibrous preform.

10. The fibrous-preform conveying device according to claim 1, wherein the electrode control unit is configured to achieve temperature control across a large area of the fibrous preform to be conveyed by initiating changes in current flow direction, including between a fiber direction and a transverse-to-fiber direction.

Description

(1) The invention will be explained in more detail in an exemplary manner by means of the appended drawings, in which:

(2) FIGS. 1a to 1c show a schematic illustration of a preforming installation;

(3) FIGS. 2a, 2b show a schematic illustration of a first variant;

(4) FIGS. 3a, 3b show a schematic illustration of a second variant;

(5) FIGS. 4a, 4b show a schematic illustration of a third variant;

(6) FIGS. 5a, 5b show a schematic illustration of a fourth variant;

(7) FIG. 6 shows a schematic illustration of a fifth variant.

(8) FIGS. 1a to 1c show in a schematic manner a preforming installation for forming fibrous preforms 2, seen from various perspectives. The preforming installation here in the widest sense is a conveying installation 1 by way of which the fibrous preform 2 is moved in the conveying direction R.sub.F. The fibrous preform 2 is brought into the desired shape by means of two forming rollers 3a and 3b which are configured as a pair and display corresponding profiling to form the fibrous preforms 2, as is illustrated in FIG. 1c in the sectional view. With the aid of such a preforming installation 1, a U-profile can therefore be generated from a planar fibrous preform 2.

(9) In FIG. 1 b an axial sectional view of the forming rollers 3a and 3b is shown. The forming roller 3b here depicts a circumferential face 4b in a U-profile, which correspondingly communicates with the circumferential face 4a of the forming roller 3a such that a planar fibrous preform can be brought into the desired U-profile shape.

(10) As will be discussed in more detail herebelow, according to the invention an electrode and/or counter electrode, which are/is disposed in the circumferential face 4a, 4b of the forming rollers 3a, 3b such that the electrode and/or counter electrode is in contact with the fibrous preform during the forming operation, are/is provided on one or both forming rollers 3a and 3b. On account thereof, a current flow in the fibrous preform 2 can be initiated during the forming operation such that, on account of the electric resistance of the fibrous preform 2, thermal energy can be introduced into the fibrous preform 2.

(11) On account of the thermal input into the fibrous preform, the latter can be consolidated in terms of its shape, for example, by thermal activation of a binder material, for example, such that the desired preform shape as illustrated in FIG. 1c is fixed and is permanently present even after the preforming operation, without the fibrous preform losing its shape.

(12) FIGS. 2a, 2b show in a schematic manner an illustration of a first variant of the arrangement of the electrodes and counter electrodes. For reasons of clarity, the electric power source is not illustrated. FIG. 2a here shows a plan view onto the fibrous preform 2 to be conveyed, with its contact rollers 3a, 3b, while FIG. 2b shows a lateral view.

(13) In the exemplary embodiment of FIGS. 2a, 2b at least two roller pairs 5 and 6 which in each case display two contact rollers 5a, 5b, and 6a, 6b are provided. The upper contact rollers 5a and 6a of the roller pairs 5, 6 here display on their circumferential face the electrode, while the lower contact rollers 5b, 6b carry on their circumferential face the respective counter electrode.

(14) At least in each case one contact roller of the two roller pairs 5, 6 here is configured such that the former imposes a force in the direction of the fibrous preform 2, such that the fibrous preform which is guided through between the respective contact rollers 5a, 5b, and 6a, 6b of the two roller pairs 5, 6 is compacted in the contact region, such that the fibers are subjected to corresponding compacting here. On account thereof, the transfer resistance is reduced, such that a current flow in the fibrous preform between the electrode and the counter electrode of the respective roller pair 5, 6 is initiated. In the exemplary embodiment of FIGS. 2a, 2b the current flow here is perpendicular to the fiber plane.

(15) It is furthermore shown in the exemplary embodiment of FIGS. 2a, 2b that a plurality of rollers or roller pairs, respectively, of this type are provided in a separate manner, on account of which the fibrous preform 2 can be temperature controlled across a large area. However, it is also conceivable for the electrodes and/or counter electrodes to be provided in multiples on one and the same roller, wherein the electrodes and/or the counter electrodes are then disposed so as to be isolated in relation to one another. On account thereof, the complexity of the installation can be reduced.

(16) It is furthermore indicated in the exemplary embodiment of FIGS. 2a, 2b that the roller pair 6 is connected to a corresponding conveying drive, such that the rollers 6a, 6b of the roller pair 6 are configured for conveying the fibrous preform 2 in the conveying direction.

(17) FIGS. 3a, 3b show in a schematic manner a second variant of the present invention. Here, a roller pair which displays a first contact roller 7a and a second contact roller 7b, between which the fibrous preform 2 is then guided through, is provided. Both the electrode and also the counter electrode here are in each case disposed so as to be spaced apart from one another on a contact roller 7a, 7b, on account of which a current flow which is transverse to the conveying direction is initiated in the fibrous preform. The electrode and the counter electrode here are provided so as to be isolated on the respective roller 7a, 7b.

(18) Of course, it is conceivable here for not only one electrode and counter electrode to be provided, but for a plurality of electrodes and counter electrodes which are in each case alternatingly disposed along the roller, for example, to be provided.

(19) Furthermore, in FIGS. 4a, 4b a schematic illustration of a third variant is shown in which a roller pair 6, 7 which in each case displays two contact rollers 6a, 6b, and 7a, 7b is provided. The contact rollers 6a, 6b of the roller pair 6 here merely display the electrode, while the contact rollers 7a, 7b of the roller pair 7 display the counter electrode. The roller pairs 6 and 7 here are disposed so as to be spaced apart from one another, for example spaced apart in the conveying direction, such that a current flow in the fibrous preform between the roller pair 6 and 7 is initiated.

(20) FIGS. 5a, 5b show in a schematic manner a fourth variant of the present invention, in which a roller pair 8 which is composed of two contact rollers 8a and 8b is provided. At least one of the contact rollers, in the exemplary embodiment here the contact roller 8b, is here configured such that the electrodes and/or counter electrodes are/is configured so as to radially project in relation to the roller, such that a type of bowed roller or pitted roller results. The individual bows or pits, i.e. the radially projecting electrodes and/or counter electrodes, here are distributed across the circumferential face such that a relief-type circumferential face of the contact roller 8a results. In the region of the pits or bows of the roller, respectively, the contact pressure is concentrated in a small area, such that intense compacting of the fibers is achieved in this region, as a result of which the transfer resistance in this region is reduced, leading to a defined current flow through a plurality of fiber layers, in particular.

(21) Finally, FIG. 6 shows a fifth variant in which a contact roller 9 is illustrated, the electrodes and counter electrodes being distributed across the circumference of the circumferential face 9a of said contact roller 9, as is schematically indicated in the cross-sectional illustration of FIG. 6. Here, the electrode and the counter electrode are disposed on a roller 9 such that they are in each case disposed so as to be radially spaced apart on the roller, in contrast to the second variant of FIGS. 3a, 3b, where the counter electrode and the electrode are disposed so as to be axially spaced apart.

LIST OF REFERENCE SIGNS

(22) 1 Fibrous-preform conveying device

(23) 2 Fibrous preform

(24) 3a, 3b Profiled contact roller

(25) 4a, 4b Circumferential face of the respective contact roller 3a, 3b

(26) R.sub.F Conveying direction

(27) 5, 6 Roller pair

(28) 5a, 5b Contact rollers of the roller pair 5

(29) 6a, 6b Contact rollers of the roller pair 6

(30) 7 Roller pair

(31) 7a, 7b Contact rollers of the roller pair 7

(32) 8 Roller pair

(33) 8a, 8b Contact rollers of the roller pair 8

(34) 9 Contact roller

(35) 9a Circumferential face of the contact roller 9

(36) + Electrode

(37) Counter electrode