Gripping apparatus

Abstract

A gripping apparatus is disclosed for gripping and holding electrically conductive, textile materials. The gripping apparatus includes a gripping device which has a gripping face for gripping and holding the textile material. With the aid of an electrical contact device, electrodes can be brought into contact with the textile material in order to bring about a current flow in the textile material.

Claims

1. A gripping apparatus for gripping and holding electrically conductive, textile materials, comprising a gripping device which has a gripping face that faces a textile material to be gripped and is configured to grip and hold the textile material; and an electrical contact device which has at least one electric electrode that is connectable to a source of electric power in order to apply an electric voltage, said at least one electric electrode being configured to come into electrical contact with the textile material and interacting with at least one electric counterelectrode such that a current flow in the textile material between the at least one electric electrode and the at least one electric counterelectrode is brought about for temperature control when the at least one electric electrode and the at least one electric counterelectrode have been brought into contact with the textile material, wherein the gripping device is configured to carry out a relative travel movement of the gripping face of the gripping device with respect to the at least one electric electrode of the electrical contact device.

2. The gripping apparatus according to claim 1, wherein the gripping device is configured as one or more of an adhesive gripper, electro-adhesive gripper, suction gripper, Bernoulli gripper, magnetic gripper, freezing gripper and needle gripper.

3. The gripping apparatus according to claim 1, wherein the at least one electric electrode is arranged within the gripping face of the gripping device.

4. The gripping apparatus according to claim 1, wherein the at least one electric electrode includes a plurality of electric electrodes.

5. The gripping apparatus according to claim 4, wherein the electrical contact device includes a control unit which is configured to switch the application of the electric voltage to the plurality of electric electrodes such that either the electric voltage for bringing about a current flow in the textile material is applied simultaneously to all of the plurality of electric electrodes or the electric voltage for bringing about a current flow in the textile material is applied to the plurality of electric electrodes or pairs of electric electrodes temporally in succession.

6. The gripping apparatus according to claim 1, wherein the electrical contact device includes the at least one electric counterelectrode.

7. The gripping apparatus according to claim 1, wherein the at least one electric electrode has a contact face smaller than 15 cm.sup.2.

8. The gripping apparatus according to claim 7, wherein the contact face of the at least one electric electrode is smaller than 5 cm.sup.2.

9. The gripping apparatus according to claim 8, wherein the contact face of the at least one electric electrode is smaller than 1 cm.sup.2.

10. The gripping apparatus according to claim 1, wherein the gripping device has at least one actuator which is configured to actively carry out the relative travel movement of the gripping face.

11. The gripping apparatus according to claim 1, wherein the gripping device has at least one spring element which is configured to passively carry out the relative travel movement of the gripping face when a force acts on the gripping face.

12. The gripping apparatus according to claim 1, wherein the electrical contact device has at least one actuator which is configured to carry out a relative travel movement of the at least one electric electrode of the electrical contact device with respect to the gripping face of the gripping device.

13. A laying apparatus for laying textile material for producing a textile preform, comprising a molding tool; and a gripping apparatus for laying the textile material in the molding tool, the gripping apparatus comprising a gripping device which has a gripping face that faces the textile material to be gripped and is configured to grip and hold the textile material, and an electrical contact device which has at least one electric electrode that is connectable to a source of electric power in order to apply an electric voltage, said at least one electric electrode being configured to come into electrical contact with the textile material and interacting with at least one electric counterelectrode such that a current flow in the textile material between the at least one electrode and the at least one counterelectrode is brought about for temperature control when the at least one electrode and the at least one counterelectrode have been brought into contact with the textile material, wherein the gripping device is configured to carry out a relative travel movement of the gripping face of the gripping device with respect to the at least one electric electrode of the electrical contact device.

14. The laying apparatus according to claim 13, wherein the molding tool has a tool surface in which the at least one counterelectrode is arranged or which forms the at least one counterelectrode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail by way of example and with reference to the appended drawings, in which:

(2) FIG. 1shows a schematic illustration of a gripping apparatus according to the invention;

(3) FIG. 2shows a schematic illustration of the gripping apparatus with a gripped textile material;

(4) FIG. 3shows a schematic illustration of the gripping apparatus during the deposition of the textile material.

DETAILED DESCRIPTION

(5) FIG. 1 schematically shows the gripping apparatus 1, by way of which electrically conductive, textile materials, such as semifinished fiber products for producing fiber composite components, are intended to be gripped and held.

(6) The gripping apparatus 1 has a gripping device 2, which has a gripping face 3, which faces the textile material to be gripped and is configured to grip and hold the textile material. The gripping face 3 of the gripping device 2 is subdivided into a plurality of partial gripping faces in the exemplary embodiment in FIG. 1.

(7) The gripping apparatus 1 furthermore has an electrical contact device 4, which has a plurality of electric electrodes 5 which are arranged between the individual partial gripping faces 3 of the gripping apparatus 2.

(8) The individual electrodes 5 of the electrical contact device 4 are in this case connected to a control unit 6 in order in this way to be able to switch the application of an electric voltage by means of a source of electric power (not illustrated). Thus, it is for example conceivable for the individual electrodes 5 to be switched temporally in succession such that an electric voltage is always applied to one electrode 5 in each case temporally in succession.

(9) FIG. 1 schematically shows the gripping apparatus 1 in the state in which a textile material is not being gripped or held. The gripping face 3 is in this case not aligned with the contact faces 7 of the electrodes 5, and so the contact faces 7 of the electrodes 5 would not come into contact with the textile material during gripping and holding of a textile material.

(10) FIG. 2 schematically shows the gripping apparatus 1 from FIG. 1, wherein a textile material 9 is now being gripped and held by the gripping faces 3 of the gripping device 2. It can be seen in this exemplary embodiment that the contact faces 7 of the electrodes 5 are not in contact with the textile material.

(11) The gripping device 2 can be configured for example as an adhesive gripper, electro-adhesive gripper, suction gripper, Bernoulli gripper, magnetic gripper, freezing gripper and/or needle gripper. Preferably, the gripping face 3 is an electro-adhesive film which is provided with a plurality of conductor tracks for example from a flexible film. By applying very high voltages to these conductor tracks, textiles resting against the film can be gripped such that an electro-adhesive force acts on the textile material 8 in the direction of the gripping apparatus 1.

(12) If the entire gripping face 3 were larger than the blank to be gripped, use can be made for example of holding-down means (not illustrated) which push away the non-required edges of the gripping face 3. Since the attractive force for example in the case of the electrostatic gripping principle depends enormously on distance, the attractive forces for the peripheral regions are reduced to such an extent that the latter are no longer gripped.

(13) The individual partial gripping faces of the gripping face 3 can be controllable for example independently of one another such that for example different partial gripping faces are switchable on and off. As a result, different semifinished fiber products can be gripped and deposited in a defined manner on a conducting or non-conducting deposition plate.

(14) The gripping apparatus 1 has a fastening device 9, by way of which the gripping apparatus 1 can be fastened for example to a robot unit. As a result, it is possible for the textile materials to be able to be transported by means of the robot from a fiber providing means to a molding tool in order in this way to create a textile preform. The gripping apparatus 1 is thus adaptable to the particular situation in an extremely flexible manner.

(15) FIG. 3 schematically shows the process of depositing the picked-up textile material 8 onto already deposited textile materials 10 which have been deposited in a molding tool 11 in order to produce a preform.

(16) In order to improve the deposition process, the gripping device 2 has spring elements 12, which may be for example an elastomeric material (for example foam). As a result, it is possible for the gripping face 3 to be able to carry out a travel movement in the direction R.sub.Hub with respect to the stationary electrodes 5, in order in this way to bring the contact faces 7 of the electrodes 5 into contact with the textile material 8.

(17) For this purpose, the gripping apparatus 1 is pushed in the direction of the already deposited textile materials 10 during the deposition of the picked-up textile material 8, wherein the pressure force with which the gripping apparatus 1 is pushed in the direction of the already deposited fiber materials 10 is greater than the spring force of the spring element 12. The spring element 12 is then compressed, wherein the gripping face 3 in this case carries out a relative travel movement in the direction R.sub.Hub with respect to the electrodes 5, specifically until the contact faces of the electrodes 5 are aligned with the gripping face 3 and the electrodes thus come into electric contact with the textile material 8.

(18) As shown in FIG. 3, the electrodes 5 come into contact with the textile material 8 such that a current flow to a counterelectrode can be brought about by application of a voltage. In the exemplary embodiment in FIG. 3, the molding tool 11 is in this case configured in an electrically conducting manner such that the molding tool 11 forms the counterelectrode. By application of a voltage, it is thus possible for a current flow to be brought about in a defined manner through the individual layers of the textile materials 8, 10, such that temperature control takes place in these regions. In this case, for example binder materials can be thermally activated so that the textile material 8 to be deposited is stuck to the already deposited textile materials 10. The gripping apparatus 1 can now be removed without the material layers slipping, and be detached from the textile material 8.

(19) It is also conceivable for the gripping device, rather than spring elements, to have active actuators in order to generate a relative movement of the gripping face 3 with respect to the electrodes 5. It is also conceivable for the electrodes themselves to be connected to actuators in order to carry out a relative movement with respect to the gripping faces 3.

(20) Furthermore, it is conceivable for the electrodes to be pushed onto the textile materials by continued application of a contact pressure force, such that the textile materials are compacted in the region of the electrodes 5. As a result, the current flow can take place in a more defined manner.

(21) Thus, a gripping apparatus which has one or more individual gripping faces and one or more associated, individually controllable electrodes for local binder activation for the purpose of sticking semifinished fiber products together is proposed. The gripping faces and the electrodes are in this case movable relative to one another. The relative movement can take place passively, in that for example a robot pushes the gripper onto a surface and parts of the gripper yield. The relative movement can also take place actively by way of drives which move the gripping faces and/or the electrodes.

(22) The current flow can run either perpendicularly through one or more fiber layers or in the fiber plane. A large number of electrodes per face allows a large number of fixing points, without the costs for the gripper being increased considerably thereby. The electrodes can in this case be controlled individually such that the current flow always flows in a defined manner via selected electrodes and only generates heat and only consumes energy where it is required.

(23) It is furthermore conceivable for the resistances applied to the electrodes to be measured before a current flow is generated. This allows optimal process parameters for the fixing operation to be set automatically. If the electrodes do not make contact with a fiber material, this is sensed and these electrodes are no longer energized in the following step.

(24) The gripping face can be flexible and thus adapt to the contours or irregularities of the textile material to be gripped. The gripping face can additionally contain holes in order to favor lifting or releasing of the item to be gripped, in that an air stream is generated for example through the holes.

(25) In order to avoid damage to the textile materials, the electrical power can be introduced in a pulsed form.

(26) If, for example, the electrodes are likewise movable via actuators relative to the gripping faces, then after the electrodes have been brought into contact with the textile material, the electrode can be moved in the direction of the textile material in order to apply a pressure thereto, resulting in the electrode pushing against the deposited textile material. As a result, the contact resistance is reduced and a current can flow between the electrode, the textile material and a counterelectrode.

LIST OF REFERENCE SIGNS

(27) 1 Gripping apparatus

(28) 2 Gripping device

(29) 3 Gripping face

(30) 4 Electrical contact device

(31) 5 Electrode

(32) 6 Control unit

(33) 7 Contact face

(34) 8 Textile material

(35) 9 Fastening device

(36) 10 Deposited textile materials

(37) 11 Molding tool

(38) 12 Spring element

(39) 13 Current flow