Hollow profile member such as a tube made of thermosetting composite materials and corresponding method

Abstract

A method for overmolding a thermoplastic tip onto a hollow profile member made of thermosetting composite and to an assembly including a thermosetting profile member and a thermoplastic tip, wherein it includes machining the shape of the profile member made of thermosetting composite on the injection region; positioning a cap in the profile member; thermally conditioning the profile assembly and the cap; and injecting the tip with thermoplastic composite in order to create the junction of the profile member, the cap and the tip.

Claims

1. A method for overmolding a thermoplastic end-fitting on a hollow profile member made of thermosetting composite to produce a connecting rod, the method including: machining a shape of the profile member made of thermosetting composite on an injection zone, and the profile member having an internal profile; positioning a plug in the profile member at an end, of the profile member, in order to prevent the profile member from being filled with the thermoplastic, the end of the profile member constituting an overmolded end, the plug including an external profile, and at least a part of the external profile complementing the internal profile of the profile member and of substantially identical size to the internal profile of the profile member, so as to plug the profile member, the profile member and the plug constituting an assembly; thermally conditioning the assembly; and injecting thermoplastic composite so as to form the end-fitting, and to create a junction of the profile member, the plug, and the end-fitting, to produce the connecting rod.

2. The method as claimed in claim 1, including a step of chemical treatment of the profile member in the injection zone.

3. The method as claimed in claim 2, wherein the positioning of the plug is done by positioning the plug in an injection tool, then by installing the profile member in the injection tool.

4. The method as claimed in claim 1, further including a step of laser treatment of the profile member in the injection zone.

5. The method as claimed in claim 4, wherein the positioning of the plug is done directly on the profile member.

6. The method as claimed in claim 4, wherein the positioning of the plug is done by positioning the plug in an injection tool, then by installing the profile member in the injection tool.

7. The method as claimed in claim 1, wherein the positioning of the plug is done directly on the profile member.

8. The method as claimed in claim 1, wherein the positioning of the plug is done by positioning the plug in an injection tool, and then by installing the profile member in the injection tool.

9. The method as claimed in claim 2, further including a step of laser treatment of the profile member in the injection zone.

10. The method as claimed in claim 2, wherein the positioning of the plug is done directly on the profile member.

11. A connecting rod comprising: a hollow profile member made of thermosetting composite of internal diameter D.sub.1 and of external diameter D.sub.2, and the profile member including an internal profile that includes the internal diameter D.sub.1, and the profile member includes a machined part at an end of the profile member; a thermoplastic end-fitting; and a plug arranged inside the profile member, the plug including an external profile, and wherein the plug is arranged on the end of the profile member in order to prevent the profile member from being filled with the thermoplastic, and the end of the profile member constituting an overmolded end, the plug having at least a part of the external profile, of the plug, (a) complementing the internal profile, of the profile member, and (b) of substantially identical size as the internal profile, of the profile member, so that the plug plugs the profile member, the machined part including machined shapes, and wherein the machined part provides mechanical linking of the profile member to the end-fitting, with the machined shapes on the profile member provided to hold the end-fitting on the profile member by the mechanical linking.

12. The connecting rod as claimed in claim 11, wherein the machined part of the profile member is pierced.

13. The connecting rod as claimed in claim 12, wherein the plug has an external diameter D.sub.1 smaller than the internal diameter D.sub.1 of the profile member, and the external diameter D.sub.1 extending over a portion of a length of the plug.

14. The connecting rod as claimed in claim 13, wherein the plug has a peripheral edge of diameter d.sub.2 greater than the external diameter d.sub.2 of the profile member.

15. The connecting rod as claimed in claim 12, wherein the plug has a peripheral edge of diameter d2 greater than the external diameter d.sub.2 of the profile member.

16. The connecting rod as claimed in claim 11, wherein the machined part of the profile member has received a laser treatment.

17. The connecting rod as claimed in claim 16, wherein the plug has a peripheral edge of diameter d.sub.2 greater than the external diameter d.sub.2 of the profile member.

18. The connecting rod as claimed in claim 11, wherein the plug has a peripheral edge of diameter d2 greater than the external diameter d.sub.2 of the profile member.

19. The connecting rod as claimed in claim 11, the machined shapes include a plurality of holes in the profile member, and the end-fitting entered into the holes.

20. The connecting rod as claimed in claim 19, wherein: the at least a part, of the external profile of the plug, is an end of the plug having an external diameter d.sub.o; and a further part of the external profile, of the plug, extending from the end of the plug toward the end of the profile member, and the further part having an external diameter d.sub.1 that is less than the external diameter d.sub.o, such that a space is provided (a) along the further part, and (b) between the profile member and the plug, the end-fitting entered into the holes so as to fill the space and provide the mechanical linking; and the end-fitting entered into an open end, at the end of the profile member, such that the end-fitting further fills the space.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features will also emerge to the person of ordinary skill in the art on reading the examples hereinbelow, illustrated by the attached figures, given by way of example:

(2) FIG. 1 is a first example of a profile member according to some embodiments,

(3) FIG. 2 represents a second example of a profile member according to some embodiments,

(4) FIG. 3 is a third example of a profile member according to some embodiments,

(5) FIG. 4 is a cross section of an embodiment of the assembly before injection according to some embodiments,

(6) FIG. 5 is a cross section of another embodiment of the assembly before injection according to some embodiments,

(7) FIG. 6 is a partial cross-sectional view of the assembly of FIG. 4 after injection,

(8) FIG. 7 is a cross-sectional view of an assembly after injection.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

(9) The profile member 1 illustrated in FIG. 1 is a hollow tube made of thermosetting composite material, for example thermosetting carbon, produced or not by pultrusion, with an end machined with holes 10. These holes 10 will allow the passage of the thermoplastic material into the profile member 1.

(10) In FIG. 2, the profile member 1 has an end with furrows 11. The length 1 of the part with furrows will possibly have substantially the same length as the thermoplastic material injection zone 13.

(11) In FIG. 3, the profile member 1 has an end with asperities 12, and they will be able to be produced by machining or by laser. The area of the asperities will possibly be substantially of the same length 1 as the thermoplastic material injection zone 13. Other forms of surfaces are also possible.

(12) FIG. 4 shows a cross section of a profile member made of thermosetting composite material with a first type of plug 2 made of thermoplastic material or metal material or a combination of the two materials, inserted into the profile member 1 under the injection zone 13 corresponding to the part of the profile member 1 including the machined end or with furrows or asperities. The plug 2 includes an end 20 whose diameter d.sub.0 is substantially equal to the internal diameter D1 of the profile member 1 in order to ensure the seal-tightness of the profile member 1 to the thermoplastic material which will be injected by plugging the opening. Here, the plug 2 will be held by the injection tool in the profile member 1, for example by an internal threading (not represented). There remains a space 15 between the profile member 1 and the plug 2.

(13) In FIG. 5, this is a cross section of a tube made of thermosetting composite material with a second type of plug 3 made of thermoplastic material or of metal material or a combination of the two materials, with an end 30 of diameter d.sub.0 substantially equal to the internal diameter D.sub.1 of the profile member 1 and a peripheral edge 31 of diameter d.sub.2 greater than the external diameter D.sub.2 of the profile member 1 and bearing on its end 14. It is the peripheral edge 31 which holds the plug 3 at the end of the profile member 1. There remains a space 15 between the profile member 1 and the plug 3.

(14) FIG. 6 shows the partial cross section of the profile member 1 of FIG. 1 with a plug 2 of the first type after injection of the thermoplastic material forming the end-fitting 4. The thermoplastic material is entered into the holes 10 to fill the space 15 which allows a better adhesion of the end-fitting 4 on the profile member 1.

(15) FIG. 7 is a cross section of a profile member of FIG. 1 with a plug 3 of the second type after the injection of the end-fitting 5. The thermoplastic material forming the end-fitting 5 has been molded around the profile member 1 in the machined part.

(16) The implementation of the method according to some embodiments takes place as follows: starting from a profile member 1, machining is performed such as that of FIGS. 1 to 3, then a plug 2 is inserted into the injection tool, for example by screwing onto an element of the tool, then the profile member is inserted into the injection tool as in FIG. 4, or, the plug 3 is placed in the profile member 1 as in FIG. 5 to then place it in the injection tool, the assembly of the profile member 1 and of the plug 2 or 3 is then thermally conditioned in the injection tool, then the thermoplastic material is injected into a mold in the shape of the end-fitting 4 or 5. Depending on the form of the machining of the profile member, the thermoplastic material will enter into the holes 10, or the furrows 11, or between the asperities 12.

(17) Obviously, an end-fitting will be produced at each end of the profile member 1 to produce a connecting rod.