BONDING OBJECTS TOGETHER

Abstract

Methods of bonding a first object to a second object, including the steps of: providing the second object having a protrusion; providing the first object having a thermoplastic material; positioning the first object relative to the second object such that an assembly of the first and the second object is formed; applying a relative force between the second and first objects and applying mechanical vibration to the assembly of the first and the second object until at least a flow portion of the thermoplastic material becomes flowable and flows around the protrusion; and causing the thermoplastic material to re-solidify. The first object may be a connecting element including a feedthrough, wherein the second object has a corresponding opening. The protrusion may be deformed such that the protrusion has an undercut relative to an axis along which the first and second objects are pressed against each other.

Claims

1. A method of bonding a first object to a second object, wherein the first object is a connecting element, the method comprising the steps of: providing the second object, the second object comprising a protrusion and an opening; providing the first object, the first object comprising a thermoplastic material and a feedthrough; positioning the first object relative to the second object such that an assembly of the first and the second object is formed; applying a relative force between the second and first objects and applying mechanical vibration to the assembly of the first and the second object until at least a flow portion of the thermoplastic material becomes flowable and flows around the protrusion; causing the thermoplastic material to re-solidify.

2. The method according to claim 1, wherein the feedthrough comprises at least one of a conduit of a fluid, and an electrical feedthrough.

3. The method according to claim 2, wherein the first object is at least one of a plug, and of a socket.

4. A method of bonding a first object to a second object, comprising the steps of: providing the second object, the second object comprising a protrusion, wherein the protrusion does not form an undercut; providing the first object, the first object comprising a thermoplastic material; deforming the protrusion; positioning the first object relative to the second object such that an assembly of the first and the second object is formed; applying a relative force between the second and first objects and applying mechanical vibration to the assembly of the first and the second object until at least a flow portion of the thermoplastic material becomes flowable and flows around the protrusion; causing the thermoplastic material to re-solidify.

5. The method according to claim 4, wherein deforming the protrusion comprises deforming the protrusion to have an undercut with respect to axial directions.

6. The method according to claim 4, wherein the second object comprises an opening, and wherein positioning the first object relative to the second object comprises positioning the first object in a manner that after the step of causing the thermoplastic material to re-solidify the first object extends at least partially through the opening.

7. The method according to claim 1, wherein the protrusion runs around the opening.

8. The method according to claim 7, wherein after the step of causing the thermoplastic to re-solidify the re-solidified thermoplastic material together with the protrusion forms a seal around the opening.

9. The method according to claim 1, comprising the step of deforming the protrusion and further comprising the steps of providing a deformation element and of positioning the deformation element relative to the protrusion, and wherein the step of deforming the protrusion comprises deforming the protrusion by applying a force to the protrusion via the deformation element.

10. The method according to claim 9, wherein the first object comprises the deformation element.

11. The method according to claim 1, wherein the step of positioning the first object relative to the second object comprises bringing the thermoplastic material of the first object in contact with the protrusion.

12. The method according to claim 1, wherein the first object comprises a first portion comprising the thermoplastic material and a second portion comprising an elastomer.

13. The method according to claim 12, wherein the second portion is arranged and the relative force and mechanical vibration are applied for a time sufficient such that the second portion is pressed against the second object.

14. The method according to claim 4, wherein in the step of providing the second object the second object has an opening, and wherein the method further comprises the step of positioning a sealing ring around the opening.

15. The method according to claim 1, wherein the thermoplastic material becomes soft but not liquid during the step of applying the relative force and mechanical vibration.

16. The method according to claim 1, wherein the second object is a die cast object.

17. The method according to claim 16, wherein the protrusion is made by die casting, optionally with a post-processing step.

18. The method according to claim 4, wherein the second object comprises a fastening portion having a positive fit shape with an undercut, wherein the step of positioning the first object relative to the second object comprises positioning an extension of thermoplastic material relative to the fastening portion and wherein the step of applying the relative force and mechanical vibration causes the extension of the thermoplastic material to flow such that the fastening portion and the extension constitute a positive fit between the first and second object after re-solidification of the thermoplastic material.

19. The method according to claim 18, wherein the step of providing a second object comprises providing a second object comprising an opening and wherein the fastening portion runs around the opening.

20. The method according to claim 1, wherein the first object comprises a recess in which thermoplastic material is arranged and wherein the step of positioning the first object relative to the second object comprises bringing the protrusion in contact with the thermoplastic material arranged within the recess.

21. A connecting element for use in a method according to claim 1, wherein the connecting element comprises a thermoplastic material, an elastomeric material, and a feedthrough, wherein the thermoplastic material and the elastomeric material have characteristics that differ such that one of the thermoplastic material and the elastomeric material softens at a lower applied force and at lower applied mechanical energy compared to the other one.

22. The connecting element according to claim 21, wherein the elastomeric material is arranged in a recess formed by the thermoplastic material and wherein it is the elastomeric material that softens at a lower applied force and at lower applied mechanical energy.

23. The connecting element according to claim 21, wherein the elastomeric material is arranged at the connection element to form a seal and wherein it is the thermoplastic material that softens at a lower applied force and at lower applied mechanical energy.

24. A connecting element for use in a method according to claim 1, the connecting element comprising a central portion with an electrical feedthrough or a feedthrough for a fluid, and the connecting element further comprising a peripheral portion, the peripheral portion running around the central portion, the peripheral portion comprising a proximally facing coupling surface and a distally facing connecting element surface portion, the connecting element surface portion comprising a thermoplastic material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0127] Hereinafter, principles and embodiments of the invention are illustrated in drawings. All drawings are schematic and not to scale. The drawings are used to explain the invention and embodiments thereof and are not meant to restrict the scope of the invention. In the drawings, same reference numbers refer to same or analogous elements. Terms designating the orientation like proximal, distal, etc. are used in the same way for all aspects and drawings. The drawings show:

[0128] FIGS. 1 and 2 Embodiments of a method according to the first aspect of the invention;

[0129] FIGS. 3 and 4 Exemplary arrangements and shapes of protrusions;

[0130] FIGS. 5-7 Embodiments of the step of deforming the protrusion;

[0131] FIGS. 8 and 9 Embodiments of a first object including a deformation element;

[0132] FIG. 10 An embodiment of the method including a second object with a fastening portion;

[0133] FIG. 11 An embodiment with a first object including an elastomer;

[0134] FIG. 12 An embodiment including a sealing ring;

[0135] FIG. 13 Yet a further embodiment of a method according to the first or second aspect of the invention;

[0136] FIG. 14 An embodiment according to the first aspect of the invention including a protrusion that is arranged in an opening of the second object; and

[0137] FIGS. 15-19 Further exemplary arrangements and shapes of protrusions.

DETAILED DESCRIPTION OF THE INVENTION

[0138] FIG. 1 shows an embodiment of a method according the first aspect of the invention schematically.

[0139] In the shown embodiment, a first object 1 including a feedthrough 21 in the shape of a pipe is provide. The first object 1 is made of a thermoplastic material, for example by injection molding, except a possible finishing (for example, coating) of the portions of the first object 1 forming the feedthrough 21.

[0140] Further, a second object 2 including a protrusion 3 and an opening 20 is provided.

[0141] The protrusion 3 includes an undercut in an axial direction such that the first and second object are secured after bonding against forces normal to the first and second object surface portion.

[0142] The protrusions 3 are arranged at a surface of the second object 2 (called the second object surface portion 31 in the following), the surface is intended to be in contact with a corresponding surface of the first object 1 (called the first object surface portion 30 in the following).

[0143] The first object 1 is positioned relative to the second object 2 such that the first object surface portion 30 is parallel to the second object surface portion 30 and such that the protrusion 3 is aligned with an intended joining location at the first object 2.

[0144] The intended joining location can be given by a shape of the first object 1 that is complementary to a shape of the second object 2, for example a portion of the first object 1 can be dimensioned to engage with the opening 20, and/or with an indentation 6 in the first object surface portion 30, wherein a portion of the protrusion 3 facing the first object surface portion 30 is equipped to engage with the indentation 6.

[0145] A relative force between the first object 1 and the second object 2 and mechanical vibration are applied by the use of a sonotrode 9. The sonotrode 9 includes a coupling face 33 that is adapted to a coupling surface 32 of the object (in the embodiment shown the first object 1) to which it is put in contact for applying the relative force and the mechanical vibration. In the embodiment shown, the sonotrode 9 is a ring sonotrode including an opening in extension of the feedthrough 21.

[0146] On the right of FIG. 1, the first and second objects after bonding are shown. The protrusion 3 is embedded in thermoplastic material of the first object 1. Further, the feedthrough 21 forms a connection between the side of the second object 2 from which the first object 1 was bonded to the second object 2 and a side opposite to the side from which the first object 1 was bonded to the second object 2.

[0147] The protrusion 3 can run around the opening 21 continuously, as shown in FIG. 4 for example, and/or other means can be present for a connection between the first object 1 and second object 2 that forms a seal, as shown in FIGS. 10-12, for example.

[0148] The steps shown in FIG. 1 are representative for embodiments according to the second aspect of the invention too as embodiments of the second aspect include the steps shown. However, embodiments of the second aspect differ from embodiments of the first aspect in the first and second object provided and in the further step of deforming the protrusion 3, in particular.

[0149] FIG. 2 shows a variation of the embodiment shown in FIG. 1, in which a connector for power, (electrical) signals etc. is provided.

[0150] The feedthrough 21 of the connector form a plug by extending from a proximal side of the first object 1 towards a distal side of it. However, the feedthrough 21 is not a thoroughgoing feedthrough 21. Rather the feedthrough 21 includes a dead end formed by a contact element 23.

[0151] The contact element 23 is in conductive contact to a wire 22. The wire 22 runs from the contact element 23 to the distal end of the first object 1, i.e. to the side of the first object 1 that is opposite to the side from which the first object 1 is bond to the second object 2

[0152] On the right of FIG. 2, the first object 1 (connector) and second object 2 after bonding are shown. The protrusion 3 is embedded in thermoplastic material of the first object, wherein the protrusion 3 and the thermoplastic material form a positive fit connection.

[0153] FIGS. 3 and 4 depict exemplary arrangements and shapes of the protrusion 3. A top view of a first object 1 bonded on top of the second object 2 is shown, i.e. the coupling surface 32 of the first object 1 including an inlet to the feedthrough 21 and the part of the second object surface portion 31 that is not in contact with the first object surface portion 30 is visible, whereas the indicated position(s) and shape(s) of the protrusion(s) 3, and the opening 20 are covered by the first object 1.

[0154] Four distinct protrusion 3 are shown in FIG. 3. One can envisage to user less, for example 1, 2 or 3 distinct protrusion, or more, for example 5, 6, 8 or 10, distinct protrusion.

[0155] In particular, distinct protrusion are very suitable for methods according to the second aspect of the invention, i.e., in application aiming for the bonding of a first object 1 that does not need to be a connecting element and hence does not need to have a feedthrough 21 to a second object 2 that does not need to have an opening 20.

[0156] The distinct protrusions can be arranged according to the needs of the bonding to be established, e.g., according to a load distribution expected during use of the bonded first and second objects, and/or they can be arranged such that a step of deforming the protrusions 3 can be performed without one protrusion 3 hindering the deformation of another protrusion 3.

[0157] The protrusion shown in FIG. 4 includes a shape such that the protrusion runs uninterruptedly, i.e., continuously, around the opening 20. Such a protrusion 3 is very suitable for the generation of a sealed connection between the first and second objects.

[0158] FIGS. 5-7 show embodiments of the step of deforming the protrusion 3. The situation at the beginning of the step is shown on the left in each figure. The situation at the end of the step is shown on the right in each figure.

[0159] The steps results in a protrusion 3 that includes an undercut such that a separation of the first object 1 and the second objects 2 in a direction normal to the second object surface 31 is prevented. This step can be present in all embodiments according to the first or second aspect of the invention.

[0160] Deformation elements 10 that include a higher resistivity against deformation than the protrusion 3 in the case of a force being applied along an axis that runs parallel to the second object surface portion 31 are shown. In other words: If the deformation element 10 is pushed against the protrusion 3 by a movement that is parallel to the second object surface portion 31, it is the protrusion 3 that deforms.

[0161] FIG. 5 shows a deformation element 10 that has the shape of a rod. The cross-section of the rod along a plane parallel to the second object surface portion 31 can be rectangular or round, for example.

[0162] The rod can include a recess such that a surface of the rod is in contact with a surface of the protrusion 3 during the step of deforming the protrusion 3.

[0163] The rod can extend in a direction normal to the drawing plane. In particular, the rod can be adapted to the shape and/or extension of the protrusion 3.

[0164] In the embodiment of FIG. 6, the deformation element 10 has the shape of a wedge wherein the protrusion 3 includes a first protrusion portion 3.1 and a second protrusion portion 3.2. At least the tips of the protrusion portions are spaced apart such that a distal end portion of the wedge can be pushed between the first and second protrusions.

[0165] Further, the first protrusion portion 3.1 can be separate from the second protrusion portion 3.2 for most of their extensions along an axis perpendicular to the second object surface portion 31, at least. Hence, the wedge pushes the first and second protrusion portions away from each other but does not divide a one piece protrusion body into two portions.

[0166] The protrusion 3 is deformed by pushing the wedge towards the second object 2 along an axis normal to the second object surface portion 31.

[0167] FIG. 7 shows a deformation element 10 that includes a deformation recess 11. The deformation recess 11 is arranged to engage with the protrusion 3 and to deform the protrusion 3 by a movement of the deformation element 10 parallel to the second object surface portion 31.

[0168] FIGS. 8 and 9 depict embodiments in which the first object 1 includes the deformation element 10.

[0169] In the embodiment of FIG. 8, the first object 1 includes a first part including the deformation element 10, for example a deformation element 10 according to FIG. 7, and a second part next to the first part including the thermoplastic material.

[0170] The first and second parts of the first object 1 are attached rigidly to each other.

[0171] A method including a first object 1 as shown in FIG. 8 includes the further steps of: [0172] Engaging the deformation recess 11 and the protrusion 3, for example by pushing the protrusion 3 into the deformation recess 11; [0173] Deforming the protrusion 3 by a movement of the first object 1, the movement being a movement relative to the second object 2 and being along an axis parallel to the second object surface portion 31; [0174] Disengaging the protrusion 3 and the deformation recess 11;

[0175] FIG. 9 shows an embodiment, in which the deformation recess 11 defines the location of embedding the protrusion 3 in the thermoplastic material, too.

[0176] This is done by a deformation recess 11 that includes a wall that is partly formed by the deformation element 10 and partly by the thermoplastic material.

[0177] The part of the deformation element 10 that forms the wall of the deformation recess 11 can be part of a load frame 15. The load frame 15 can be rigidly connected to a tool used for guiding the first object 1. In particular, it can be rigidly connected to the sonotrode 9.

[0178] A method including a first object 1 as shown in FIG. 9 includes the further steps of: [0179] Engaging the deformation recess 11 and the protrusion 3, for example by pushing the protrusion 3 into the deformation recess 11; [0180] Deforming the protrusion 3 by a movement of the first object 1, the movement being a movement relative to the second object 2 and being along an axis parallel to the second object surface portion 31; and

[0181] A further positioning of the first object 1 relative to the second object 2 may not be needed, anymore.

[0182] An alternative method including a first object 1 as shown in FIG. 9 includes the step of engaging the deformation recess 11 and the protrusion 3, for example by pushing the protrusion 3 into the deformation recess 11, and further includes modifying the step of applying a relative force and mechanical vibration such that the step includes the following two sub-steps: [0183] Applying a relative force between the second and first objects without applying mechanical vibration, such that the protrusion 3 deforms whereas the thermoplastic material remains in its solid state. In other words, the protrusion deforms but the first object 1 does not deform. [0184] Applying a relative force between the second and first objects and applying mechanical vibration to the assembly of the first and the second object until at least a flow portion of the thermoplastic material becomes flowable and flows around the deformed protrusion (3).

[0185] The relative force applied in the step without mechanical vibration can differ from the relative force applied in the step including the impingement of mechanical vibration.

[0186] A partial or complete release of the relative force applied can be done between the step without mechanical vibration and the step including the impingement of mechanical vibration.

[0187] FIGS. 10-12 show embodiments that are in particularbut not onlysuitable for connections between the first object 1 and the second object 2 that form a seal.

[0188] In the embodiment according to FIG. 10, the second object 2 includes a fastening portion 4 in the shape of cavity that forms an undercut with respect to axial directions. The cavity can be accessed by an opening in the second object surface portion 31.

[0189] The first object 1 includes a thermoplastic extension 5 that protrudes from the first object surface portion 30.

[0190] The dimensions of the thermoplastic extension 5 can be adapted to the dimensions of the fasting portion 4. This can include an extension in a direction normal to the drawing plane.

[0191] A method including a first object 1 and a second object 2 as shown in FIG. 10 includes the further steps of: [0192] Positioning the first object 1 relative to the second object 2 such that the thermoplastic extension 5 is in contact to and/or engages with the protrusion 3; and [0193] Pushing the thermoplastic extension 5 into the fastening portion 4;

[0194] Further, the step of applying the relative force between the first object 1 and the second object 2 and applying mechanical vibration further includes liquefying the thermoplastic extension 5 such that the thermoplastic material and the fastening portion 4 form a positive fit connection after re-solidification of the thermoplastic material. In particular, the thermoplastic extension 5 is liquefied such that is fills the cavity of the fastening portion 4 at least partly.

[0195] In the embodiment according to FIG. 11, the first object 1 includes a first portion 12 including or consisting of the thermoplastic material 36 and a second portion 13 consisting of an elastomer 35.

[0196] The second portion 13 protrudes from the first object surface portion 30 and is arranged to deform elastically, in particular if a force normal the first object surface portion 30 is applied.

[0197] An embodiment of the method providing said first object 1 including the first portion 12 and the second portion 13 does not differ from any other embodiment according to the first or second aspect of the invention. However, the relative force and mechanical vibration are applied until the second portion 13 is compressed between the first object surface portion 30 and the second object surface portion 31.

[0198] The embodiment shown in FIG. 12 is an alternative to the embodiment shown in FIG. 11, wherein the second portion 13 is replaced by a sealing ring 14.

[0199] In the embodiment shown, the sealing ring is positioned within a recess in the second object surface portion 30. The recess runs around the opening 20 of the second object is more distant from the opening 20 than the protrusion 3.

[0200] More in general, a sealing ring of the described kind can be shaped and placed to run around the protrusion or to run around the opening, with the protrusion running around the sealing ring.

[0201] FIG. 13 depicts a further embodiment of the first or second aspect of the invention, wherein the first object 1 includes an elastomeric material 36 in a recess 34 of the first object 1, wherein the thermoplastic material 36 forms the recess.

[0202] In the embodiment shown, the elastomeric material 36 has thermoplastic properties, too. In other words, it is a thermoplastic elastomer.

[0203] The thermoplastic material 36 has characteristics such that it does not deform during a method according to any embodiment according to the first or second aspect of the invention.

[0204] In a method including a first object 1 as shown in FIG. 13, the step of positioning the first object 1 relative to the second object 2 includes bringing the recess 34 in contact with the protrusion 3. Further, it is the elastomeric material 36 that becomes flowable in the step of applying the relative force and the mechanical vibration. Hence, the protrusion 3 is embedded in the elastomeric material 36.

[0205] Consequently, the first object 1 and the second object 2 are bonded such that a limited movement of the first object 1 relative to the second object 2 is still possible after bonding. In particular, the recess 34 is dimensioned such that a movement parallel to the first and second object surface portions is possible, for example by a depth of the recess that is only slightly larger than a height of the protrusion 3, wherein the depth of the recess is its extension perpendicular to the first object surface portion 30 and the height of the protrusion 3 is its extension perpendicular to the second object surface portion 31.

[0206] FIG. 14 shows an embodiment according to the first aspect of the invention including the protrusion 3 arranged in the opening 20 of the second object 2.

[0207] In the embodiment shown, the protrusion 3 is formed by protruding from a lateral wall of the opening 20.

[0208] The embodiment of FIG. 14 shows the optional feature of the opening 20 having a first portion 20.1 with a first diameter 28 and a second portion 20.2 with a second diameter 29, wherein the second diameter 29 is smaller than the first diameter 28. In the embodiment shown, the decrease from the first diameter 28 to the second diameter 29 is step-wise such that a surface 25 is formed, the surface 25 being oriented perpendicular to a longitudinal axis 26 of the opening 20.

[0209] The protrusion 3 protrudes from the lateral wall of the first portion 20.1 such that the effective size of the opening 20 in the first portion 20.1 depends on the position along the longitudinal axis 26. In particular, the protrusion 3 protrudes from the lateral wall of the first portion 20.1 such that the first diameter 28 is diminished locally.

[0210] The surface 25 formed by the decrease in diameter is arranged to cause the thermoplastic material of the first object 1 that is in contact with the surface 25 (this means the flow portion of the first object 1) after the step of positioning the first object 1 relative to the second object 2 to become flowable during the step of applying the relative force and the mechanical vibration. Further, it serves to direct flowable thermoplastic material in a manner that it flows partly around the protrusion 3, at least.

[0211] The surface 25 formed by the decrease in diameter is arranged distally of the protrusion 3. Hence, a positive-fit connection between the first and second object is formed after the flowable thermoplastic material has been directed in radial direction and after re-solidification of the thermoplastic material.

[0212] One can envisage other orientations of the surface 25 formed by the decrease in diameter as well as other shapes and positions of the protrusion 3 protruding from the lateral wall than shown in FIG. 14 as long the surface 25 and the protrusion 3 are arranged relative to each other in a manner that a positive-fit connection between the first and second object is formed.

[0213] FIGS. 15-18 show further exemplary arrangements and shapes of protrusions 3. The arrangements and shapes shown can be used in the method according to the first aspect of the invention, in particular in an embodiment thereof as disclosed in FIG. 14. However, the arrangements and shapes shown can also be used in the method according to the second aspect of the invention, wherein the lateral wall is a sidewall of the second object 2 and the surface 25 is formed by a step in said sidewall, for example.

[0214] In FIG. 15 the protrusion 3 is tapered and the first object 1 is positioned in the step of positioning the first object 1 relative to the second object 2 in a manner that it is pressed against a proximal surface of the tapered protrusion 3 during the step of applying the relative force and the mechanical vibration.

[0215] The surface 25 is arranged relative the tapered protrusion 3 in a manner that it directs flowable thermoplastic material radially behind a distal surface of the tapered protrusion 3.

[0216] In FIG. 16 the protrusion 3 is tapered and the first object 1 is positioned in the step of positioning the first object 1 relative to the second object 2 in a manner that it is pressed against the surface 25 during the step of applying the relative force and the mechanical vibration.

[0217] The surface 25 is arranged distally of the tapered protrusion 3 such that it directs flowable thermoplastic material radially behind a distal surface of the tapered protrusion 3.

[0218] In FIG. 17, the second object 2 includes a plurality of protrusions 3 that are arranged on the lateral wall (the sidewall, as the case may be). The length of the protrusions 3 depends on their position on the lateral wall and increases from proximally to distally. This has the effect that the first object 1 does not need to be positioned with high accuracy during the step of positioning the first object 1 relative to the second object 2 and/or that the objects, in particular the first object 1, does not need to be produced with tight production tolerances. This is because a second object 2 as shown in FIG. 17 offers different possible locations where thermoplastic material of the first object 1 can be made flowable and different possible locations where a positive-fit connection can be established.

[0219] The plurality of protrusions 3 shown in FIG. 18 do not vary in length. This can cause a more reliable, rigid and/or stable bond between the first and second object as a plurality of positive-fit connections can be formed.

[0220] FIG. 19 shows a protrusion 3 that is arranged on the surface 25 formed by the decrease in diameter or on the step in the sidewall of the second object 2.

[0221] The protrusion 3 can form an undercut or it can be deformable to form an undercut as disclosed above.

[0222] The protrusion 3 arranged on the surface 25 (the step in the sidewall as the case may be) can be combined with the protrusion 3 protruding from the lateral wall (the sidewall). The combination of a protrusion arranged on the surface 25 and a further protrusion arranged on the lateral wall can cause a bonding of the first and second object based on positive-fit connections along perpendicular axes.