Method for producing a common connecting opening in two components, at least one of which is made from a plastically deformable material

Abstract

A method is provided for producing a common connecting opening in two components, at least one of which is made from a plastically deformable material. In the method, at least the edge region of a first prefabricated opening of the first component is softened in order subsequently to introduce a mandrel which displaces the material softened by the heating so that a common connecting opening having a predetermined diameter is obtained.

Claims

1. A method for producing a common connecting opening in two components, at least one of which is made from a plastically deformable material, comprising the steps: providing a first component made of a plastically deformable material, the first component having a first opening, a first sidewall around the first opening, and a thickness at the first opening defined in an axial direction at the first sidewall, providing a second component having a second opening, a second sidewall around the second opening, and a thickness at the second opening defined in the axial direction at the second sidewall, assembling the first component and the second component so that the first opening and the second opening lie on one another, enclosing the first component and the second component between a first restricting body and a second restricting body in an edge region around the respective opening, softening the material at least of the edge region of the first component, heating a mandrel, introducing the mandrel into the first and second openings so that softened material moves between the two edge regions and surrounds the mandrel in order to provide a common connecting opening, and setting the material, the mandrel having an outer diameter which corresponds to a target diameter of the common connecting opening, wherein the first opening has a first opening radius, wherein the second opening has a second opening radius, wherein the mandrel has a mandrel outer radius, and wherein the first opening radius, the second opening radius and the mandrel outer radius are dimensioned in such a way that, when the mandrel is introduced and extends through the first opening and the second opening, the first component, the second component and the mandrel are in flush surface contact with one another, and a sum of the thickness at the first opening of the first component and the thickness at the second opening of the second component is unchanged.

2. The method according to claim 1, wherein the softening of the material comprises softening of the material of the edge regions of the first component and the second component.

3. The method according to claim 1, wherein the first opening has a smaller diameter than the second opening.

4. The method according to claim 1, wherein a mandrel outer diameter is greater than a diameter of the first opening and less than a diameter of the second opening.

5. The method according to claim 1, wherein the mandrel is driven from a cavity arranged in the first restricting body into a second cavity of the second restricting body.

6. The method according to claim 1, furthermore comprising the use of a connecting element as the mandrel, which remains in the common connecting opening after the setting of the material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features, advantages and application possibilities of the present invention may be found from the following description of the exemplary embodiments and figures. In this case, all features described and/or depicted per se and in any combination form the subject-matter of the invention, independently of their formulation in the individual claims or the back-referencing of the latter. In the figures, references which are the same furthermore denote objects which are the same or similar

(2) FIG. 1 shows two components, a second restricting body and a mandrel in a three-dimensional view.

(3) FIG. 2 shows the view of FIG. 1 with additional markings to illustrate position discrepancies.

(4) FIG. 3 shows the two components in a position lying on one another with a mandrel brought close to the first opening.

(5) FIG. 4 shows the two components in a lateral section.

(6) FIG. 5 shows the two components, two restricting bodies and the mandrel in first positions in a lateral section.

(7) FIG. 6 shows, in a lateral section, the two components, two restricting bodies and the mandrel of FIG. 5 in a second position.

(8) FIG. 7 shows, in a lateral section, the two components, two restricting bodies and the mandrel of FIG. 5 in a third position.

(9) FIG. 8 shows, in a lateral section, the two components, two restricting bodies and the mandrel of FIG. 5 in a fourth position.

(10) FIG. 9 shows the connecting opening with a connecting element inserted therein.

(11) FIG. 10 shows a connecting element with one indentation in a lateral section.

(12) FIG. 11 shows a connecting element with two indentations in a lateral section.

(13) 12a shows the two openings and the connecting opening in a lateral section.

(14) FIG. 12b also shows the two openings and the connecting opening in a lateral section.

(15) FIG. 12c additionally shows the two openings and the connecting opening in a lateral section.

(16) FIG. 13a shows the connecting opening with an indentation in a lateral section.

(17) FIG. 13b also shows the connecting opening with an indentation in a lateral section.

(18) FIG. 14a shows a first connecting opening with a connecting element arranged therein.

(19) FIG. 14b shows a second connecting opening with a connecting element arranged therein.

(20) FIG. 14c shows a second connecting opening with a connecting element arranged therein.

(21) FIG. 14d shows a second connecting opening with a connecting element arranged therein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(22) FIG. 1 shows a first component 2 and a second component 4, which in this case, by way example, are made from a fiber-reinforced plastic. The components 2 and 4 may consequently comprise reinforcing fibers in the form of short or long fibers, for instance carbon fibers, which are embedded in a matrix made of a thermoplastic. This may for instance comprise polyamide, polyetherimide, PEKK, PEEK, PAEK, PPS or other suitable materials.

(23) FIG. 1 furthermore shows a mandrel 6, which is guided in a first restricting body (not represented here) in a first cavity formed therein, so that it can be moved in the axial direction. The mandrel 6 is configured by way of example as a cylindrical body having a conically pointed end. A second restricting body 8 is arranged on an opposite side of the second component 4.

(24) The first component 2 has a first opening 10, while a second opening 12 is provided in the second component 4. The openings 10 and 12 are shown as circular openings, which might be suitable for the production of a connecting opening, but is not absolutely necessary, as will be explained below. The second restricting body 8 comprises a second cavity 14, which is surrounded by a second restricting surface 16. For example, the two components 2 and 4 are respectively represented as being flat. Each component 2, 4 may of course also have a much more complexly shaped structure.

(25) For example, the first opening 10 is smaller than the second opening 12. Furthermore, the two openings 10 and 12 do not lie concentrically above one another, but form a lateral offset. This may be attributable to production-related dimensional tolerances. Provision is made to integrate the openings 10, 12, during the production of the components 2, 4, directly into one another. Especially in the case of relatively large dimensions of the components 2 and 4, it is conceivable that an offset may be fully avoided. The offset is denoted in more detail in FIG. 2 with the aid of marking lines. Both the first opening 10 and the second opening 12 are arranged off-center with respect to the mandrel 6.

(26) As represented in FIG. 3, as a preparatory step the two components 2 and 4 are placed on one another so that the openings 10 and 12 lie on one another. The second restricting body 8 is furthermore placed directly below the second opening 12 so that the second opening 12 is located over the second cavity 14. The mandrel 6 is in a starting position directly above the first opening 10.

(27) FIG. 4 shows a sectional representation in which the two openings 10 and 12 lie above one another. The difference in the diameters of the two openings 10, 12 is in this case clear. By way of example, however, the material thicknesses of the two components 2 and 4 are selected to be substantially equal. The aim is to provide, with the two openings 10 and 12, a uniformly shaped and stepless common connecting opening through which a connecting means can be passed and fastened.

(28) FIG. 5 shows an extended sectional representation with the second restricting body 8, which is arranged flush next to the second component 4 at the second opening 12. This leads to surface contact between the second restricting surface 16 and the second component 4. Arranged on the opposite side, there is furthermore a first restricting body 18, which in a similar way to the second restricting body 8 comprises a first cavity 20 in which the mandrel 6 is guided. The second restricting body 8 and the first restricting body 18 are preferably oriented with one another in such a way that the cavities 14 and 20 are aligned with one another. As is represented with the aid of movement arrows, the first restricting body 18 is driven onto the first component 2 in the region of the first opening 10.

(29) The resulting arrangement is represented in FIG. 6. In this case, the mandrel 6 is still fully in the first cavity 20 and the openings 10 and 12 are enclosed between the cavities 14 and 20. The two restricting bodies 8 and 18 may likewise exert a mechanical pressure on the components 2 and 4, so that there is flush surface contact between the latter. Heating is carried out of at least the second restricting surface 16 and a first restricting surface 22 on the first restricting body 18, so that the thermoplastic matrix material of the two components 2 and 4 is softened at least in edge regions 26 and 28 of the components 2, 4. The application of a heating power for the softening could be carried out by action of ultrasound, and electrical heating resistor, friction by rotation of a tool and/or of the mandrel 6 or using other, even externally arranged, devices. The aim is to soften the edge regions 26 and 28 in such a way that the mandrel 6 can be driven unimpeded through the openings 10 and 12 and can thereby displace softened material 24. The shape of the openings and 12 is thereby influenced and a desired common connecting opening is finally produced.

(30) After the heating, the mandrel 6 is therefore initially moved into and through the first opening 10, in order subsequently to be driven into the second opening 12 so that the second cavity 14 is subsequently reached. Because of the softening of the material, displacement of the material takes place out of the edge region 26 of the first component 2 in the direction of the second component 4. This is only indicated here, and the representation is not true to scale. Because of the restricting bodies 8 and 18 adjacent to the components 2 and 4, material can be displaced arbitrarily by the mandrel 6, but is restricted to spreading and the available cavity between the restricting surfaces 16 and 22, by displacement of the softened material 24 present at another position, into the edge regions 26 and 28. The introduction of the mandrel 6 consequently leads to a modified distribution of the material.

(31) After the mandrel 6 has been driven fully, a common connecting opening 30 is obtained in which the softened material of the second component 2 is pressed, for example in the shape of a ring or socket, into the second opening 12. With a sufficient temperature and compatibility of the materials of the components 2 and 4, the softened material of the two components 2 and 4 may join together with a material fit so that the two components 2 and 4 are welded to one another in the edge regions 26 and 28.

(32) As represented in FIG. 9, after the connecting opening 30 has been prepared, a connecting means in the form of a bolt 32 having a nut 34 and a washer 36 may be applied on the connecting opening 30. Rivet connections may have of course also be envisaged, for instance with screw or blind rivets. As mentioned above, a connecting element may also be used as a mandrel. Furthermore, a rotation of the connecting element by friction may also lead to heating of the edge regions 26 and 28 and therefore softening of the material. If it is used as a mandrel in the context of the method, the connecting element may also remain in the common connecting opening 30 after the production thereof.

(33) For optional shaping of at least one axial end of the connecting opening 30, a mandrel 38, which is represented by way of example in FIG. 10, may be used. Instead of a continuously cylindrical shape, this has a widening lateral surface 40 which leads to an indentation 42 by pressing into or onto the first component 2. A die is therefore provided, which additionally defines the shape of an axial end surface of the common connecting opening. The merely schematically indicated second restricting body 8 may be configured as in the preceding figures.

(34) As is furthermore represented in FIG. 11, it is also possible to use a second restricting body (not shown here) which has a similar contour for forming a further indentation 44 at an opposite axial end of the connecting opening.

(35) In principle, in the procedure according to the invention, the selection of the sizes of the first opening 10, of the second opening 12 and of the mandrel is not entirely independent and freely selectable, but rather a constant volume of the material must also be taken into account during the insertion of the mandrel 6. As represented in FIGS. 12a and 12b, the first opening 10 has a first radius R1, and the second opening has a second radius R2. The mandrel 6 has a mandrel outer radius Rf. The radii R1, R2 and Rf are to be adapted to one another in such a way that, with a constant material thickness t1, t2, a flush surface contact is induced between the fully inserted mandrel 6 and inner edges of the openings 10 and 12. The volumes V1 and V2 defined by the openings 10 and 12 then correspond to a volume Vf occupied by the mandrel inside the two components 2 and 4 according to FIG. 12c.

(36) As is noted in FIGS. 13a and 13b, additional volume Vc is of course also to be taken into account for optional indentations, if for example the mandrel 38 is used.

(37) The connecting opening 30 formed in this way may, as shown in FIGS. 14a to 14d, be used to receive a very wide variety of connecting elements 46, 48, 50 and 52.

(38) In addition, it is to be pointed out that the terms “comprise” and “comprising” do not exclude any other elements or steps, and “a” or “one” does not exclude a multiplicity. Furthermore, it is to be pointed at the features which have been described with reference to one of the exemplary embodiments above may also be used in combination with other features of other exemplary embodiments described above.

(39) While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). The terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

LIST OF REFERENCES

(40) 2 first component

(41) 4 second component

(42) 6 mandrel

(43) 8 second restricting body

(44) 10 first opening

(45) 12 second opening

(46) 14 second cavity

(47) 16 second restricting surface

(48) 18 first restricting body

(49) 20 first cavity

(50) 22 first restricting surface

(51) 24 softened material

(52) 26 first edge region

(53) 28 second edge region

(54) 30 common connecting opening

(55) 32 bolt, connecting element

(56) 34 nut

(57) 36 washer

(58) 38 mandrel

(59) 40 lateral surface

(60) 42 indentation

(61) 44 indentation

(62) 46 connecting element

(63) 48 connecting element

(64) 50 connecting element

(65) 52 connecting element

(66) R.sub.1 radius of the first opening

(67) R.sub.2 radius of the second opening

(68) R.sub.f radius of mandrel

(69) V.sub.1 volume of first opening

(70) V.sub.2 volume of second opening

(71) V.sub.f volume of connecting opening

(72) V.sub.c additional volume