WO2021078593A1

WO2021078593A1 - Tool and method for producing a workpiece

Info

Publication number: WO2021078593A1
Application number: PCT/EP2020/078819
Authority: WO
Inventors: Martin CEE ABU; Jens Werner; André BARTSCH
Original assignee: ThyssenKrupp Carbon Components GmbH; Thyssenkrupp Ag
Priority date: 2019-10-25
Filing date: 2020-10-14
Publication date: 2021-04-29
Also published as: DE102019216512A1

Abstract

The invention relates to a tool (20) for producing a workpiece from a textile semi-finished product (13), having a first half-shell (1) with a first housing (1a) and having a second half-shell (2) with a second housing (2a). In an unclamped state, the textile semi-finished product can be positioned between the half-shells, and the first half-shell can be clamped with the second half-shell from an unclamped state into a clamped state in a clamping direction. The tool additionally has a clamping device (17) with a needle (3) which can be moved in the clamping direction and opposite the clamping direction, wherein the needle (3) is arranged in the first housing and has a groove (3a), the second housing has a locking device (16), by means of which the needle is locked in the second housing in the clamped state, and a clamping force is applied to the needle in the clamping direction in the clamped state in order to clamp the first half-shell with the second half-shell.

Description

Tool and method for manufacturing a workpiece

The invention relates to a tool and a method for producing a workpiece from a semi-finished textile product.

When manufacturing workpieces from, for example, carbon fiber reinforced plastics (CFRP for short), preforming takes place through shaping and the semi-finished textile products are stabilized using special shapes.

For this purpose, the (fiber) semi-finished product is draped in so-called tool shells, which are then clamped together and thus together result in the closed tool. Binder activation then takes place, for example in the form of heat input into the tool, so that the fiber structure of the CF semi-finished product hardens. The protruding material is then cut off at the tool edges.

In particular, to automate this production, also called preform production, it is necessary to provide tool shells on the one hand for frictional clamping and on the other hand for unimpeded trimming of the tool edges and also for heat input via the tool shells.

It is also necessary that the bracing and opening of the tool shells is implemented with the least possible effort.

Proceeding from this, the invention is based on the object of specifying a tool and a method with the aid of which a simple and, in particular, automated production of a workpiece is made possible and in particular the requirements mentioned above are met.

The object directed to the tool is achieved according to the invention by a tool for producing a workpiece having the features of claim 1. The object directed to the method is achieved according to the invention by a method for producing a workpiece having the features of claim 14.

Advantageous refinements, developments and variants are the subject matter of the subclaims. The advantages and preferred configurations listed with regard to the tool are to be transferred accordingly to the method and vice versa. The tool is designed for the production of a workpiece from a textile semi-finished product and specifically for the production of the CF semi-finished product mentioned at the beginning.

The tool has a first part shape with a first housing and at least one second part shape with a second housing. The number of partial forms is not limited to two, so that in particular multi-part partial forms or several partial forms can be used in order to produce almost any physical structure as a fiber composite body. Preferably, but not necessarily, the first part shape and the at least second part shape are designed to be complementary / corresponding to one another.

A cavity is formed between the two partial molds, that is to say between the first partial mold and the at least second partial mold. The cavity is used, for example, to hold a semi-finished textile product and / or to infiltrate it with a resin.

A needle is also provided. The first housing and the second housing can be penetrated by the needle. Furthermore, the first part shape can be clamped with or by the needle with the at least second part shape.

The advantage here is that the first part shape and the at least second part shape can be braced and at the same time an edge area of the part shapes remains free. Remaining free can be understood to mean that in particular no bracing elements for bracing the two partial shapes are arranged at the edge regions. Furthermore, bracing by means of the needle has proven to be advantageous with regard to bracing with little effort. There is thus no need for complex bracing and locking mechanisms.

In a preferred embodiment, the tool has a first part shape with a first housing and at least one second part shape with a second housing. The first housing and the first part shape are integrally formed, that is to say monolithically. Analogously to this, the at least second partial shape and the second housing are designed in one piece, that is to say monolithically.

In an untensioned state, the semi-finished textile product can be positioned between the first part shape and the at least second part shape. Furthermore, the first part shape is with the at least second part shape in a bracing direction of can be clamped from the untensioned state into a tensioned state. The bracing direction can be understood to mean a direction in which the first part shape is pressed or braced onto the at least second part shape.

Furthermore, the tool has a clamping device with a needle that can be moved in and against the clamping direction, the needle being arranged in the first housing. The needle also has a groove.

In addition, the second housing has a locking device with which the needle is locked in the second housing in the clamped state. In the clamped state, the needle is still used to clamp the first part shape with the at least second part shape with a clamping force that acts in the clamping direction.

The advantage of the tool is that it enables automatic draping, i.e. H. Equipping and bracing of the two partial forms is made possible and at the same time it is possible to dispense with complex bracing and locking mechanisms. Furthermore, the tool according to the invention is advantageous with regard to cutting the edges of the finished workpiece, since the clamping of the two partial forms does not follow the workpiece edges to be cut. At the same time, with the tool according to the invention, a reduced cycle time associated with automation is taken into account in the above-mentioned cutting of the workpiece edges. At the same time, the tool simplifies the automation of preforming production.

In one embodiment, the locking device has two oppositely arranged dowel pins. In this context, opposing can be understood to mean that the two clamping pins are opposite one another, that is to say that the tips of the clamping pins are oriented towards one another. Furthermore, the dowel pins are aligned transversely to the clamping direction. In this context, transverse can be understood to mean that the dowel pins are oriented essentially at right angles to the clamping direction.

Furthermore, a gap is formed between the dowel pins for receiving the needle, in which the needle is arranged in the clamped state, the dowel pins, especially the tips of the dowel pins, with the groove of the needle forming a locking connection to lock the needle in the second housing . For this purpose, the groove in the clamped state in the gap is preferably arranged at the same height as the dowel pins. In one embodiment, the clamping pins are each clamped with a spring element and with a clamping screw in the locking device. Here, the spring force of the spring element of a respective dowel pin acts in the direction of the gap, that is in each case in the direction of the other dowel pin. The Federele element is, for example, a helix spring. The bracing screw is designed, for example, as a grub screw.

When moving the needle from the first housing into the second housing, the dowel pins are initially moved apart due to their contour and the preferably beveled contour of the needle until the dowel pins snap into the groove and thus reliably lock the needle. At the end of the manufacturing process, the two partial molds are relaxed by applying a predetermined force that acts against the tensioning direction. This force releases the locking connection between the groove and the dowel pins and thus releases the two partial shapes.

Furthermore, it can be provided that stop surfaces for the dowel pins are formed in the locking device. The stop surfaces are used to limit penetration of the dowel pins into the gap both in the unstressed and in the clamped state. This ensures that the dowel pins protrude so far into the gap to form a non-positive locking connection with the groove of the needle in the clamped state, but do not protrude so far into the gap that it would not be possible to receive the needle in it, since the gap would be blocked by the dowel pins.

The groove is preferably arranged in an upper region of the needle. The upper area can preferably be understood to mean the upper 8 cm, especially the upper 5 cm and in particular the upper 3 cm starting from the tip of the needle.

In one embodiment, a spring assembly connected to the needle is arranged in the first housing. The spring package here has a spring element, for example a helical spring. The purpose of the spring assembly is to apply a spring force to the needle against the tensioning direction. This spring force corresponds to the clamping force, so that the application of the spring force by the spring package ensures that the two partial forms are clamped in the clamped state. Furthermore, the spring force of the spring assembly serves to ensure that the needle and especially the needle tip remain in the untensioned state in the first housing and do not protrude into a surface of the first part shape on which the textile fabric is / should be positioned.

In an expedient embodiment, a fixing element for fixing the spring assembly is arranged in the first housing.

According to a preferred embodiment, the fixing element has two mutually countered nuts which form a screw connection with a thread of the needle. This means that the two nuts are countered against each other and screwed onto the thread of the needle. In addition, a washer can also be provided here, which is positioned by the two nuts. The washer in turn positions and then fixes the spring assembly so that it is held in position. In this context, holding in position can be understood to mean that the spring assembly does not move in the tensioning direction in the tensioned state. If the washer is missing, the spring assembly is positioned and fixed by the two nuts.

According to a preferred embodiment, the first housing has a locking screw with a through-hole for the needle at the end opposite the first part shape. The locking screw closes the first housing and thus secures the needle, the spring assembly and other attachments within the first housing.

In one embodiment, the second housing has a bore which serves to receive and guide the needle in the clamped state. The dowel pins protrude into the bore in the clamped state and lock the needle by locking it into the groove.

According to a further embodiment, in the clamped state, the needle passes through the folded textile fabric clamped between the first part shape and the at least second part shape. This refinement is based on the idea of not bracing the two partial forms with one another at the respective edges in order to ensure edging, i.e. cutting of, for example, overhanging workpiece parts, along the workpiece edges without releasing the bracing. In the clamped state, the tool therefore has no annoying attachments along the trimming edge. In order to ensure optimal bracing of the two part molds, according to one embodiment, the two part molds are positively clamped to one another in the clamped state. Furthermore, a positive clamping of the two partial molds proves to be advantageous with regard to the quality of the workpiece to be produced.

An exemplary embodiment of the invention is explained in more detail below with reference to a figure. This shows in a partially simplified representation:

1 shows a longitudinal section through a tool.

The tool 20 here has a first part shape 1 and a second part shape 2. The first part mold 1 has a first housing la and the second part mold 2 has a second housing 2a. The first housing la and the first partial mold 1 are in one piece in the embodiment shown in FIG. 1, that is monolithic ausgebil det. Analogously to this, the second partial mold 2 and the second housing 2a are also formed in one piece, that is to say monolithically. As an alternative to this, the housings 1 a, 2 a and the partial molds 1, 2 can each be designed as separate components. Here, the housing la, 2a are then attached to the part molds 1, 2.

Furthermore, the tool 20 has a clamping device (17) with a needle 3, the needle 3 being arranged in the first housing 1a and specifically seated in it. The needle 3 also has a groove 3a. The first housing 1 a also has a spring assembly 4 that is connected to the needle 3. With the spring assembly 4, the needle 3 is subjected to spring force in a tensioning direction V. For this purpose, the spring assembly 4 has a spring element (not shown), for example a helical spring. In addition, the needle 3 is movable in and against the clamping direction V Ver.

To adjust and fix the spring assembly 4, a fixing device 15 is arranged in the first housing la, which in the exemplary embodiment has a nut 6.1 and a lock nut 6.2 and a washer 5 held by the two nuts 6.1, 6.2. Both the nut 6.1, the lock nut 6.2 and the washer 5 are thus part of the fixing device 15. The two nuts 6.1, 6.2 form a screw connection with a thread, not shown, of the needle 3. Furthermore, the first housing 1 a has a screw plug 7, which on its part has a through hole 7.1 for the needle 3.

The second housing 2a also has a locking device 16, which on the other hand has two oppositely arranged dowel pins 9.1, 9.2. The dowel pins

9.1, 9.2 are also aligned transversely to the bracing direction V. A gap 8 is formed between the dowel pins 9.1, 9.2 and serves to accommodate the needle 3. When the needle 3 is received in the gap 8 (clamped state of the two partial molds 1, 2), the dowel pins 9.1, 9.2 form a snap-in connection with the groove 3a of the needle 3 for locking and thus for clamping the partial molds 1, 2 together.

The dowel pins 9.1, 9.2 are each clamped ver with a spring element 11.1, 11.2 and each with a clamping screw 10.1, 10.2 in the second housing number 2a. The bracing screws 10.1, 10.2 are designed as Ma denschraub in the embodiment, but the design of the bracing screws

10.1, 10.2 are not limited to a grub screw. Rather, any types of known screws can be used for the design of the bracing screws

10.1, 10.2 are used.

The second housing 2a also has a bore 12 which is used to receive and guide the needle 3 in the clamped state. The two Spannstif te 9.1, 9.2 protrude into the bore for locking, that is, for forming the latching connection with the groove 3a, in the clamped state. In the tensioned state, the needle 3 is thus preferably located within the bore 12 in such a way that the groove 3a is arranged on a flute of the two dowel pins 9.1, 9.2.

In the clamped state, the needle 3 continues to pass through a textile fabric 13 clamped between the first partial mold 1 and the second partial mold 2. By forming the locking connection by means of the groove 3a and the dowel pins

9.1, 9.2 reliable and simple bracing of the two partial forms 1, 2 is guaranteed. In addition, the edges 14 of the two partial molds 1, 2 are thereby freely accessible, for example for trimming the textile fabric 13.

The invention is not limited to the embodiment described above. Rather, other variants of the invention can be derived from the specialist man without leaving the subject matter of the invention sen. In particular, all in connection with the implementation game described individual features can be combined with one another in other ways without departing from the subject matter of the invention.

List of reference symbols

1 first part form la first housing

2 second part shape

2a second housing

3 needle

3a groove

4 spring package

5 washer

6.1 mother

6.2 Counter nut

7 screw plug

7a through hole

8 gap

9.1 Roll pin

9.2 Roll pin

10.1 Bracing screw

10.2 Bracing screw

11.1 spring element

11.2 spring element

12 bore

13 textile fabric

14 margins

15 Fixing device

16 locking device

17 clamping device

V tension direction

Claims

1. Tool (20) for producing a workpiece from a textile

Semi-finished product (13), comprising:

- A first partial mold (1) with a first housing (la),

- At least one second part mold (2) with a second housing (2a), a cavity being formed between the two part molds (1, 2) and

- The first housing (la) and the second housing (2a) can be penetrated by a needle (3) and

- The first part shape (1) can be braced with the at least second part shape (2) by means of the needle (3).

2. Tool (20) for producing a workpiece from a textile

Semi-finished product (13), comprising:

- A first partial mold (1) with a first housing (la),

- At least one second part shape (2) with a second housing (2a), the semi-finished textile product (13) being positionable between the first part shape (1) and the at least second part shape (2) and the first part shape (1 ) can be braced with the at least second part shape (2) in a bracing direction (V) from the untensioned state into a braced state, and

- A tensioning device (17) with a needle (3) movable in and against the tensioning direction (V), the needle (3) being arranged in the first housing (la) and having a groove (3a), wherein

- The at least second housing (2a) has a locking device (16) with which the needle (3) is locked in the second housing (2a) in the clamped state and

- The needle (3) in the clamped state for clamping the first part shape (1) with the at least second part shape (2) is acted upon by a clamping force in the clamping direction (V).

3. Tool (20) according to claim 1, wherein the first part shape (1) and the at least second part shape (2) are each designed as half-shells.

4. Tool (20) according to claim 2 or 3, dad u rch geken nzeich net, since ss the locking device (16) has two oppositely arranged dowel pins (9.1, 9.2) which are aligned transversely to the clamping direction (V), with between the Dowel pins (9.1, 9.2) a gap (8) is formed for receiving the needle (3) and in the tensioned state the needle (3) is arranged in the gap (8), the dowel pins (9.1, 9.2) with the groove ( 3a) of the needle (3) form a latching connection for locking the needle (3) in the second housing (2a).

5. Tool (20) according to claim 4, dad u rch geken nzeich net, since ss the dowel pins (9.1, 9.2) each with a spring element (11.1, 11.2) and each with a tensioning screw (10.1, 10.2) in the locking device (16 ) are tense.

6. Tool (20) according to one of claims 2 to 5, dad u rch geken nzeich net, since ss the groove (3a) is arranged in an upper region of the needle (3).

7. Tool (20) according to one of claims 2 to 6, dad u rch geken nzeich net, as ss in the first housing (la) a with the needle (3) connected to the spring assembly (4) is arranged, through which the needle ( 3) is acted upon by spring force in the tensioning direction (V) to provide the tensioning force.

8. Tool (20) according to one of claims 2 to 7, dad u rch geken nzeich net, as ss in the first housing (la) a fixing device (15) is arranged for fixing the spring assembly (4).

9. Tool (20) according to the preceding claim, dad u rch geken nzeich net, since the fixing device (15) has two mutually countered nuts (6.1, 6.2) which form a screw connection with a thread of the needle (3).

10. Tool (20) according to one of claims 2 to 9, dad u rch geken nzeich net, that ss the first housing (la) has a screw plug (7) with a through hole (7a) for the needle (3).

11. Tool (20) according to one of claims 2 to 10, dad u rch geken nzeich net, that ss the second housing (2a) has a bore (12) for receiving and guiding the needle (3) in the clamped state.

12. Tool (20) according to one of claims 2 to 11, dad u rch geken nzeich net, that ss the needle (3) in the clamped state by the textile clamped between the first part shape (1) and the at least second part shape (2) Semi-finished product (13) passes through.

13. Tool (20) according to one of claims 2 to 12, dad u rch geken nzeich net, that ss in the clamped state, the first part shape (1) and the at least second part shape (2) are positively clamped to one another.

14. A method for producing a workpiece from a textile semi-finished product (13), comprising the following steps:

- Positioning of the semi-finished textile product (13) between a first part mold (1) of a tool (20), which has a first housing (la), and at least one second part mold (2) of the tool (20), which has a second housing (2a ), wherein a needle (3) is arranged in the first housing (la),

- Moving the needle (3) from the first housing (la) through the semi-finished textile product (13) into the second housing (2a),

- Locking the needle (3) in the second housing (2a) and applying a tensioning force to the needle (3) in a tensioning direction (V) for tensioning the first half-shell (1) with the second half-shell (2).