Anchoring a second object to a first object

Abstract

The invention provides a method of anchoring a connector in a first object, wherein the first object is a lightweight structural element having a first outer structural layer and an inner lining layer, wherein the first outer structural layer is thinner and denser than the inner lining layer, wherein the connector comprises a solid thermoplastic material, the method comprising the steps of: - bringing a distally facing coupling face of the connector into contact with an attachment site of the first outer structural layer; - displacing a portion of the first outer structural layer at the attachment site relative to the inner lining layer by applying a first pressing force to the first outer structural layer and causing the first outer structural layer to be pierced at or near the attachment site; - applying a second pressing force to the connector and transferring energy into the connector, thereby moving the connector in a distal direction relative to the first object until a flow portion of the thermoplastic material is liquefied and caused to flow into an interpenetrating structure of the inner lining layer; - stopping the energy transfer and allowing the flow portion to re-solidify.

Description

[0001] This application is a divisional application of PCT application PCT / EP2017 / 056734, which has application number 2017800273960, application date March 21, 2017, invention title "Method and machine for anchoring a connector in a first object", priority date March 21, 2016, and January 10, 2017, and has entered the Chinese national phase. Technical Field

[0002] This invention relates to the fields of mechanical engineering and manufacturing, particularly mechanical manufacturing, such as automotive engineering, aircraft manufacturing, shipbuilding, machinery manufacturing, and toy manufacturing. Specifically, it relates to a method for mechanically anchoring a connector into a first object. Background Technology

[0003] In the automotive, aerospace, and other industries, there is a growing trend to abandon steel-only structures in favor of lightweight materials.

[0004] An example of a new structural material element is a lightweight structural element comprising two outer, relatively thin structural layers and an intermediate layer (lining) disposed between the structural layers. The structural layers are made, for example, of fiber composite materials (such as glass fiber composites or carbon fiber composites), metal sheets, or, depending on the industry, fiberboard. The intermediate layer (lining) is, for example, a honeycomb structure of cardboard or other materials, or a structure of lightweight metal foam, polymer foam, or ceramic foam, or separate spacers. Such lightweight structural elements can be called "sandwich panels" and are sometimes referred to as "hollow core panels (HCBs)." They are mechanically stable, aesthetically pleasing, and relatively lightweight.

[0005] New materials present new challenges when combining components made of these materials, especially when joining slightly flatter objects to other objects. One example of this is in the automotive, aerospace, shipbuilding, and other industries, where reinforcements (“longitudinal beams”, etc.) are incorporated into slightly flat sandwich panel structures, or anchor points for hinges, screws, bolts, etc., within sandwich panels.

[0006] Furthermore, according to existing technology, reinforcements in the sandwich panel structure must be provided during their manufacture, and connecting elements must also be added during manufacturing. If these are added subsequently, the sandwich core must then be foam-filled to secure the connectors, which is costly and time-consuming.

[0007] To cope with these challenges and to eliminate possible defects, adhesive bonding has been used extensively in the automotive, aerospace and other industries. Adhesive bonding can be light and strong, but suffers from the disadvantage that it is not possible to control the reliability over time, since it is almost impossible to detect a weakened adhesive bond, for example due to embrittlement of the adhesive, without completely destroying the bond. Furthermore, adhesive bonding can lead to an increase in manufacturing costs due to material costs and delays in the manufacturing process due to the slow hardening process, especially if the surfaces to be connected to each other have a certain roughness and thus result in the inability to use thin-layer adhesives that harden quickly. In addition, adhesive bonding cannot be stronger than the material strength of the surfaces, since it is only effective at the surfaces. In sandwich panels, this is the material strength of one of the structural layers or the outermost sub-layers thereof. SUMMARY

[0008] It is therefore an object of the present invention to provide a method of mechanically fastening a connector to a first object that overcomes the disadvantages of the prior art methods. In particular, it is an object of the present invention to provide a method of mechanically fastening a connector to a lightweight structural element that has the potential advantages of being low cost, efficient and fast.

[0009] According to one aspect of the present invention, there is provided a method of anchoring a connector in a first object, wherein the first object is a lightweight structural element having a first outer structural layer (also referred to herein as a first structural layer) and an inner liner layer, wherein the first outer structural layer is thinner and denser than the inner liner layer (and is typically much harder than the average hardness of the inner liner layer defined), and wherein the connector comprises a thermoplastic material in a solid state, the method comprising:

[0010] - contacting a distally facing coupling surface portion of the connector with an attachment site of the first outer structural layer;

[0011] - displacing a portion of the first outer structural layer at the attachment site relative to the inner liner layer by applying a first pressing force to the first outer structural layer and causing the first outer structural layer to be pierced at or near the attachment site, in particular due to the application of the first pressing force;

[0012] - applying a second pressing force to the connector and delivering energy to the connector, thereby moving the connector relative to the first object in a distal direction until the flowing portion of the thermoplastic material is liquefied and flows interpenetrating the structure of the inner liner layer;

[0013] - stopping the delivery of energy and allowing the flowing portion to re-solidify.

[0014] In particular, if the first structural layer defines a plane around the attachment site, the method can comprise moving the first structural layer in a distal direction relative to the plane at the attachment site.

[0015] In the step of displacing, the displaced part of the first outer structural layer can be separated from the first outer structural layer, i.e. in contrast to merely deforming, the first outer structural layer is broken in the process. In embodiments, however, the displaced part can remain continuous, i.e. separated from the first structural layer and displaced as a whole. This does not exclude the possibility that the displaced part is deformed in addition to being separated from the first outer structural layer and displaced.

[0016] The step of displacing can in particular comprise punching out or breaking off the displaced part from the first outer structural layer.

[0017] To this end, the connector can comprise a distally facing punch surface portion (sometimes referred to herein as a 'punch edge', which can be sharp depending on the first structural layer material, but not necessarily so, also a flat end of a punch surface portion which is configured to have a punch effect). This punch surface portion can form an uninterrupted or interrupted profile along which the punching takes place. In many embodiments, the geometry of the connector is such that a hollow space is formed within the profile when the connector abuts the first structural layer, i.e. the connector has a distal portion which is approximately tubular. Here, the tube portion can have a circular cross-section or other cross-section and can have a constant or non-constant wall thickness (e.g. a tapering wall thickness).

[0018] The step of displacing a part of the first outer structural layer according to the first alternative can be carried out after bringing the coupling surface portion of the connector into contact with the first structural layer, i.e. by applying a first pressing force to the connector against the first outer structural layer. In embodiments of this first alternative, the connector can be subjected to mechanical vibration energy during the step of applying the first pressing force and / or the punch force to displace the part of the first outer structural layer. In embodiments, the amplitude of the mechanical vibration and / or power is higher during the step of displacing than during the subsequent step of applying the second pressing force, or it can be the same or even lower.

[0019] According to another aspect, the application therefore relates to a method of anchoring a connector in a first object, wherein the first object is a lightweight structural element having a first outer structural layer and an inner lining layer, the first outer structural layer being thinner and denser than the inner lining layer, wherein the connector comprises a solid thermoplastic material, the method comprising the steps of:

[0020] - bringing a distally facing coupling surface portion of the connector into contact with an attachment site of the first outer structural layer;

[0021] - simultaneously coupling a first pressing force and mechanical vibration energy into the connector until the first outer structural layer is pierced at or near the attachment site by the connector;

[0022] - applying a second pressing force to the connector and transferring energy to the connector, thereby moving the connector relative to the first object in a distal direction until the flowing portion of thermoplastic material is liquefied and flows interpenetrating the structure of the inner liner;

[0023] - stopping the energy transfer and allowing the flowing portion to re-solidify.

[0024] According to a second alternative, the step of displacing the portion of the first outer structural layer can be performed before contacting the connector with the first structural layer, i.e. by a separate pressing tool. Such a pressing tool can displace the portion of the first indentation by preforming a shallow indentation (destroying the first structural layer around the attachment site) or by stamping a portion of the first structural layer at the attachment site. Such a pressing tool can also be used to displace a portion of the first indentation by preforming an indentation without destroying the first structural layer. Then, according to the first alternative, a first pressing force is applied via the connector until piercing the first structural layer.

[0025] A combination of the first and second alternatives is easily implemented, i.e. in a first sub-step, the portion can be removed by a pressing tool, then the connector can be brought into contact with the first structural layer, and then the second sub-step of further displacing the portion can be implemented by pressing the connector against the first structural layer.

[0026] In embodiments, the connector can be provided with a distal piercing and / or stamping structure. In particular, the connector can comprise a distal stamping profile with or without interruptions, e.g. a circular profile. For example, the connector can have a substantially tubular distal portion.

[0027] In embodiments, the connector geometry can be such that it is a hollow sleeve towards the distal end, the sleeve portion extending distally from a body. Such a body in embodiments can form a head.

[0028] In general, the connector will typically have a stamping edge of the aforementioned type, which can be circumferential or interrupted and can extend along the outermost circumference of the connector or can optionally be offset radially outwards (arranging the edge along the outermost circumference has the potential advantage of conforming the hollow space created in the first structural layer to the geometry of the connector), while a slight outward taper or small outer step has the advantage of facilitating a tight fit of the connector in the first structural layer, thereby increasing the stability of the proximal and facial surface of the final assembly.

[0029] The connector does not necessarily have a circular cross-section. Rather, it can have a different shape, e.g. oblong, polygonal, T-shaped, H-shaped, U-shaped, etc.

[0030] In a special set of embodiments, the connector is provided with a collapse zone which allows a distal part of the collapse zone to deform relative to the rest of the connector (a first type of collapse zone, which is used for distal collapse). In particular, this part can be bent outwards from the collapse zone, so that the connector gets a larger footprint. Such a collapse zone can be formed by reducing the cross-sectional area, for example in a corresponding embodiment by a sleeve region of reduced thickness extending around the sleeve-like part.

[0031] In many embodiments, the connector needs to be positioned relatively precisely with respect to the first object when it is anchored to the first object.

[0032] According to a first set of embodiments, for this purpose the first object and the connector have a structure which is suitable for this purpose when the connector is in contact with the first object. In particular, the first object can be provided with a guide hole (positioning hole), which extends for example at least through the first structure layer, and the connector can comprise a correspondingly shaped guide portion which protrudes further distally than the structure (for example a punch structure) which displaces this part of the first structure layer during the process. In particular, the guide portion can comprise a pin-like structure which is rotationally symmetrical or not rotationally symmetrical with respect to the axis of rotation around the insertion axis.

[0033] Such a guide structure can be formed in a part which is collapsible in the above-described case, i.e. this part of the connector with the guide structure collapses during the process, so that the guide structure recedes and / or disappears during the process. Thus, the distal end of the guide structure can initially be the most distal part of the connector, but when the distal end of the connector approaches the inner surface of the second structure layer (if any), other parts of the connector (in particular with a larger footprint than the generally relatively thin guide portion) form the distal end or parts thereof, where the majority of the energy is absorbed.

[0034] In this first set of embodiments, the positioning of the ultrasonic generator with respect to the connector is not critical, even though the connector must have a precisely defined position. For example, an ultrasonic generator or other pressing tool can be used which has a substantially flat distal end face.

[0035] According to a second set of embodiments, a tool (ultrasonic generator or other pressing tool) can be used to press the connector in the distal direction to define the position of the connector during the anchoring process. The tool can then have a precisely defined position with respect to the first object, for example by belonging to the apparatus which holds the first object. The tool can also have a guide structure which cooperates with the guide structure of the connector to guide the connector. In one example, the ultrasonic generator comprises a guide protrusion which engages the guide indentation of the connector.

[0036] In many embodiments of the construction with a connector, a tool and an object in which the connector is anchored, it should be ensured that there is no restricted guidance of the connection (no over-determined guidance), i.e. for example if the tool (ultrasound generator) and the object both have a determined position, only one of the tool and the object can define the lateral position of the connector or neither of them can. Otherwise, uncontrolled melting can occur. This is particularly easy to achieve if the energy is mechanical vibration energy, since with vibrations, there is no any forced guidance, the lateral friction is very small, so that it is easy to achieve separation. Therefore, in embodiments, the guidance of the connector should be carried out by one of the tool, the object or an external guidance.

[0037] The connector comprises a thermoplastic material. In embodiments, the connector consists of a thermoplastic material.

[0038] In other embodiments, the connector comprises a body of non-liquefiable material in addition to the thermoplastic material.

[0039] In embodiments with a body of non-liquefiable material, the body of non-liquefiable material is not just a filler of a large number of particles, but has a macroscopic body with a determined position and orientation and has an actual size of at least 10% of the volume of the connector and / or has a characteristic dimension of at least 0.1 mm in any dimension. In particular, the body can be ceramic or metal. In particular, the body can have a determined shape, thereby increasing the stiffness of the connector. By the body, the connector is defined into at least two spatially separated regions, namely the body region and the thermoplastic region.

[0040] Such a body of non-liquefiable material can be provided with structures for further functions, such as threads, other mechanical connections, contacts or guide holes, etc.

[0041] In embodiments, the body has a surface with at least one locking portion on the lateral surface, which cooperates with the thermoplastic material and the body to stabilize the relative position of the body embedded inside the thermoplastic material.

[0042] In embodiments in which the connector comprises a non-liquefiable material in addition to the thermoplastic material, the thermoplastic material can be arranged at least at the surface portion in contact with the inner lining. Alternatively, the thermoplastic material can be arranged or able to be arranged in the interior, the body can comprise a window through which the thermoplastic material can be pressed out to come into contact with the inner lining.

[0043] According to two alternatives, the step of displacing can comprise displacing the portion in a distal direction, thereby compressing the inner lining material distal to the portion. It has been found that this compression of the inner lining can lead to additional anchoring stability.

[0044] In particular, in two alternative embodiments, the first structural layer can be punched due to the first pressing force. Then, the portion that is displaced in the displacement step can be punched out and moved relative to the rest of the first structural layer in a distal direction.

[0045] According to the first alternative discussed previously, the step of displacing the portion of the first outer structural layer is carried out after bringing the connector into contact with the first object, in particular by means of the connector. In these embodiments, there can be a challenge that the first structural layer is destroyed by the connector and that a second structural layer, which can be similar or even identical to the first structural layer, needs to remain intact if the first object is a lightweight structural element having an inner liner layer sandwiched between the first and second structural layers.

[0046] According to a first possibility of doing so, the process is carried out with distance control, i.e. the (second) pressure is stopped as soon as the connector has reached a predetermined position, so that it can be excluded that the connector also pierces the second structural layer. The first possibility is in particular an alternative for first objects, wherein the inner liner layer provides sufficient resistance against the pressure, so that enough energy is absorbed by the connector when it penetrates the inner liner material and / or if other than mechanical energy is coupled into the connector.

[0047] Additionally or alternatively, according to a second possibility, the connector can be equipped for protecting the second structural layer during the final phase, even if the distal end of the connector is pressed against the second structural layer.

[0048] For example, in embodiments, the piercing and / or punching structure can be a non- liquefiable component. Then, the connector can be equipped with a non-liquefiable component to retract relative to the thermoplastic material portion while the connector advances through the inner liner material, so that upon reaching the second structural layer, the piercing and / or punching structure no longer constitutes the distal end and / or the pressure is no longer coupled into the non-liquefiable component. For example, the non-liquefiable component can comprise a proximally facing energy conducting structure embedded in the thermoplastic material, whereby the thermoplastic material around the energy conducting structure is plastically deformed and the non-liquefiable material is allowed to displace proximally relative to the thermoplastic material after sufficient energy has been absorbed.

[0049] According to another example, the distal end comprising the piercing and / or punching structure is collapsible. In particular, the distal end comprising the piercing and / or punching structure can comprise a plurality of legs, which are initially stable, but which can be deformed, e.g. outwards, during the process. A collateral consequence of this approach is that the footprint of the anchoring is automatically enhanced by the legs extending outwards.

[0050] As an additional or alternative to collapsible distal end, the connector can comprise a collapse zone configured to collapse in a more proximal region, in particular in a region immediately after the step of applying the second pressing force distally of the first outer structural layer, whereby material displaced in the collapse zone can be displaced outwardly under (distally of) the first outer structural layer (second type of collapse zone; proximal collapse zone).

[0051] Generally, the method can comprise rendering the thermoplastic material of the connector flowable by the action of the energy and the second pressing force and / or, where applicable, the third pressing force and causing it to flow radially outwardly into the distal region of the first structural layer, in particular the region of the first structural layer immediately distally thereof (e.g. in physical contact). Thus, after re-solidification, the thermoplastic material can cause a rivet effect, the connector being fixed by the thermoplastic material and the first structural layer against being pulled proximally out.

[0052] As an additional or yet alternative to the second type of collapse zone, the connector can comprise a temporary stabilizing structure preventing the distal portion comprising the distal facing surface portion of the connector from collapsing in the initial phase. In one example, the stabilizing structure comprises at least one rib, e.g. substantially parallel to the axial extension. Such stabilizing structure has the effect of stabilizing the distal portion, e.g. the tube portion, of the connector during the initial phase of displacing the first outer structural layer and initially by advancing the connector into the first object by the second pressing force, even if the distal portion is relatively weak, e.g. constituted by a relatively weak wall. The stabilizing structure can prevent buckling or similar effects.

[0053] In embodiments, the stabilizing structure can be arranged to cause an outward pressure as a result of the connector advancing distally into the first object, the outward pressure being a result of the stabilizing structure, the compacted inner liner material being subject to an elastic resistance. Such outward pressure has the effect of displacing the liquefied and / or unliquefied thermoplastic material outwardly, e.g. under (distally of) the first outer structural layer. Such outward displacement enhances the anchoring strength after re-solidification of the thermoplastic material.

[0054] In embodiments (with or without stabilizing structure), the connector can be shaped such that the ejected displaced portion promotes or causes an outward pressure displacing the connector material outwardly. In particular, the connector can be shaped to cause a relative pressure outwardly when the displaced portion encounters a resistance preventing displacement towards more distal. As mentioned above, such resistance will be caused by the compacted inner liner. The relatively hard surface of the displaced portion can be used to promote anchoring constitution due to the density / mechanical strength of the first outer structural layer.

[0055] According to another example, the distal end comprising the piercing and / or stamping structure is sufficiently liquefied upon reaching the second structural layer to render the distal end free of any piercing and / or stamping functionality. This can for example be the case for piercing and / or stamping structures formed by a relatively thin tube section or the like.

[0056] According to yet another example, the piercing and / or stamping structure is shaped so as to be obstructed by the first object material before reaching the second structural layer. For example, the piercing and / or stamping structure can consist of an annular tubular distally facing protrusion having an extension smaller than or equal to the thickness of the first structural layer. Thereby, the extruded portion of the first structural layer fills the space enclosed by the tubular protrusion, thereby obstructing its distal end.

[0057] In another example, features of these examples can be combined.

[0058] In a set of embodiments, the connector is shaped so that after the stamping / piercing step a step of the first structural layer involves rendering flowable the thermoplastic material of the connector, in particular the portion located in the proximal region and flowing it into the region immediately distal of the first structural layer.

[0059] To this end, the connector can have a distal portion having an outer surface which is substantially cylindrical or slightly conical (cylindrical here means having translational symmetry along the axis, which includes but is not limited to a rotational cylinder). The axial extension of this distal portion corresponds at least to the thickness of the material to be stamped (the first structural layer, possibly under other hard material portions). In addition, the connector has a more proximal portion proximal to this distal portion, this more proximal portion having an outwardly protruding feature in which the connector becomes wider according to the position along the axis. Thereby, when the connector is pressed further into the first object, this outwardly protruding feature comes into contact with the edge of the first structural layer along the stamping line.

[0060] In particular, the method can thus comprise, after a portion of the first structural layer has been extruded, pressing a radially outward portion of the connector against the edge of the remaining first structural layer, while energy is coupled into the connector until the thermoplastic material of the connector becomes flowable at the interface between the edge and the connector and flows it relative to the connector and the edge.

[0061] In these embodiments, the outer surface of the connector does not have to be uniform. Rather, it can for example comprise axially extending conical ridges, for example protruding from the cylindrical surface. The intensified heating of the thermoplastic material of these ridges (if the energy is mechanical energy, the ridges can act as energy directors) can lead to the transfer of heat to the interior, for example the cylindrical portion, thereby causing a collapse of the connector during the last phase of the anchoring process.

[0062] Whether the outer surface of this radially outer portion is uniform or comprises discrete protrusions, such as ridges, the tapering angle or step size of this radially outer portion can be dimensioned to result in sufficient heat input depending on the thickness of the first structural layer (the harder the first structural layer, the smaller the tapering angle).

[0063] A quantity which can be important is the bending stiffness of the first structural layer. This quantity can depend on the material properties and thickness of the first structural layer itself as well as the compressive resistance of the inner liner.

[0064] The displaced portion can initially be slightly flat and oriented perpendicular to the proximal-distal direction. It can optionally remain substantially slightly flat and oriented perpendicular to the proximal-distal direction.

[0065] The energy transferred to the connector can be mechanical vibration energy. To this end, the connector can have a proximally facing proximal coupling input face which cooperates with a vibrating object, i.e. an ultrasonic generator, during the step of applying energy.

[0066] Here, the liquefaction of the flow portion can be caused by friction between the vibrating connector and the surface of the first object, which heats the connector and possibly also the first object superficially.

[0067] In a set of embodiments, the connector and / or a portion of the first object pressing against the connector comprises structures acting as energy directors at the mutual interface, such as edges or ridges, such as the energy directors from ultrasonic welding or for "Woodwelding" processes described in e.g. WO 98 / 42988 or WO 00 / 79137 or WO 2008 / 080238.

[0068] For coupling mechanical energy into the connector, the connector can comprise a coupling input mechanism. Such a coupling input mechanism can be a coupling input face, in particular constituted by the proximal end face with or without a guiding structure for the ultrasonic generator, such as a guiding hole for a corresponding protrusion of the tool. The area where the coupling output face of the ultrasonic generator is in physical contact with the coupling input face of the connector is referred to herein as the "contact face".

[0069] In a set of embodiments, the ultrasonic generator and the connector are shaped to fit to each other such that the contact face is confined to an area whose in-plane position corresponds to the position of the distally facing surface portion and their surroundings. In other words, at the position where the connector extends to the distal end, pressure is only coupled into the connector such that pressure is directly delivered to the distal end, mainly an axial force is coupled into the connector. In particular, if the connector has a tube portion extending distally, the contact face can be confined to an annulus, in particular having an average radius substantially corresponding to the average radius of this annulus.

[0070] By this measure, the stability of the connector during the process with respect to deformation of the central, e.g. functional portion can be enhanced.

[0071] In embodiments, especially if the inner lining layer is relatively strong and will cause a significant mechanical resistance against displacement towards the distal side, the central portion of the connector can be decoupled from the outer peripheral portion comprising the tube portion. This decoupling can be achieved, for example, by a joint structure between the outer peripheral portion and the central portion. Only the outer peripheral portion will be subjected to the (second) pressing force and energy input. By this further measure the energy input into the central portion will be reduced and, for example, deformation of the central portion by softening of the thermoplastic material of the central portion will be prevented. However, the connection structure will transmit the necessary forward pushing force on the central portion.

[0072] In order to confine the contact surface to a certain area, the ultrasonic generator can comprise a protrusion forming a coupling output face at its distal end. For example, the ultrasonic generator can comprise a circumferential protrusion extending around the outer circumference of the ultrasonic generator. Additionally or alternatively, the connector can comprise a corresponding protrusion.

[0073] In a particular subgroup of embodiments, the ultrasonic generator has a protrusion defining the contact surface, the connector has a proximal protrusion having a proximal end face proximal to the contact surface. The ultrasonic generator and the connector are adapted to each other such that the proximal end face does not form part of the contact surface, i.e. no energy input (and, for example, also no first and / or second pressing force) is applied to the proximal end face. Thus, a possible bulge formed adjacent to the contact surface during the process due to energy absorption at the interface does not have any influence on the definition of the proximal end of the connector. This can be advantageous in embodiments, in which the proximal end face of the connector needs to be defined and serves as an abutment face for some other object fixed to the first object.

[0074] It is not excluded that other forms of energy are coupled into the first object through the connector and absorbed at the interface, for example radiation energy.

[0075] In many embodiments, the first pressing force is greater than the second pressing force. This is due to the fact that the mechanical resistance of the inner lining layer tends to be significantly smaller than the mechanical resistance of the first structural layer. In embodiments comprising the application of the first pressing force through (via) the connector, the machine implementing the method is programmed to switch from the application of the greater first pressing force to the application of the smaller second pressing force as soon as the first structural layer is pierced by the connector. This is not an automatic behavior when the pressure is applied by a pneumatic device or other standard device. On the contrary, the machine is provided with a device dedicated to this purpose, for example

[0076] - a sensing mechanism for sensing the forward movement - pressure response. As soon as this mechanism senses a drop in the mechanical resistance against forward movement, the machine switches from the application of the first pressing force to the application of the smaller second pressing force. Additionally or alternatively, the acoustic properties of the system "connector - first object" can be used to sense the mechanical resistance (resonance properties, energy absorption), this information being available from the feedback loop controlling the application of the mechanical vibration energy.

[0077] - a mechanism for applying pressure based on position. The pressure is applied by the tool to the connector, and once the tool reaches a position corresponding to the position where the connector has pierced the first structural layer, the machine switches from applying a first pressing force to applying a second, smaller pressing force.

[0078] - a direct sensor, which for example optionally detects when the first structural layer has been pierced by the connector; this includes the possibility of using a camera and image processing. Also in this case, generally, once it is detected that the connector has pierced the first structural layer, the machine switches from applying a first pressing force to applying a second, smaller pressing force.

[0079] In many groups of embodiments comprising the application of a first pressing force via the connector, during the step of applying the first pressing force, energy is also coupled into the connector. This energy can be mechanical vibration energy. In embodiments, the amplitude and / or frequency of the mechanical vibrations can optionally be different from the amplitude / frequency applied during the step of applying the second pressing force. In particular, the amplitude and / or frequency can optionally be higher during the step of applying the first pressing force than during the step of applying the second pressing force.

[0080] More generally, the amplitude of the mechanical vibrations can undergo a specific amplitude modulation profile during the process. In embodiments, during the step of applying the second pressing force, the mechanical vibration energy is applied in a pulsed manner.

[0081] The first structural layer can be relatively hard and substantially non-porous, so that it does not comprise any structure or only a very small structure that can be penetrated by the thermoplastic material for anchoring the connector in the first structural layer after the thermoplastic material has re-solidified. However, it has been found that during the application of the first pressing force, which can be beneficial to improve the anchoring of the connector distally ("below") the first structural layer, mechanical vibrations have been applied. This can be attributed to the fact that in thermoplastic materials, for higher temperatures, the internal friction is greater, in particular if at temperatures above the glass transition temperature, compared to the transition below the glass transition temperature. If vibrations have been applied during the penetration of the first structural layer, this will result in heating the thermoplastic material, whereby the material becomes softer and will have a greater internal friction when subjected to mechanical vibrations. Then, when the material in the subsequent step comes into contact with the lining material (which, due to its properties, presents a significantly smaller resistance and will therefore result in a smaller internal friction), the entire energy absorption will be sufficient to continue the liquefaction process of the connector thermoplastic material in the lining layer due to the initial heating. Although the lining is quite soft, it has been observed that if the flow portion is sufficiently large, this will result in a solid anchoring within the lining material.

[0082] As an alternative to having the first structural layer be a rigid non-porous material, the first object can have a more flexible first structural layer. For example, the first structural layer can be fluffy, such as wood / polypropylene (PP) or even only partially consolidated glass fiber-PP composite.

[0083] In embodiments, anchoring the connector in the first object can comprise welding between the material of the connector and the material of the first and / or (if applicable) second outer structural layer, in addition to anchoring by the thermoplastic material interpenetrating the open spaces between the fibers.

[0084] More generally, in embodiments, the first structural layer can have thermoplastic properties. This can be used for at least one of the following:

[0085] - When energy is also coupled into the connector during the initial phase of applying the first pressing force, the first structural layer can locally heat up and thereby soften, whereby the first pressing force can be chosen to be relatively small. Additionally or alternatively, the amplitude of the vibrations (if the vibrations are mechanical vibrations) or generally the input power can be chosen to be relatively small until the first structural layer has been penetrated, especially without causing the distal end of the connector itself to soften. After the piercing (penetration), the pressure and / or amplitude / power can be increased so that the liquefaction process of the material of the connector can be started.

[0086] - In the final phase of the anchoring process, the thermoplastic material of the connector can be welded to the first outer structural layer.

[0087] In embodiments, the connector can have a proximal widening, such as a head or the like, which forms a fusion structure that is located or shaped to press against the first outer structural layer towards the end of the anchoring process, so as to become liquefied and interpenetrate the structure of the first outer structural layer and / or fuse the material of the first outer structural layer and / or the inner liner layer so as to form a weld.

[0088] Such a fusion structure can comprise an edge, such as a circumferential edge.

[0089] As a supplement or yet another alternative, the materials of the connector and the inner liner layer can be chosen such that the anchoring comprises welding between the material of the connector and the thermoplastic material of the inner liner layer, as further set out below.

[0090] In one set of embodiments, after the second press-down force is applied and before and / or after the energy transfer is stopped, but before the flow portion has fully re-solidified, the method features the additional step of applying a third press-down force, which is greater than the second press-down force and can be less than the first press-down force. Such a third press-down force can be applied once the distal end of the connector contacts the attachment layer at the interface between the second structural layer or the second structural layer and the inner liner material distal to the inner liner. In practice, such an attachment layer extends into the space of the inner liner material and is considered herein to belong to the inner liner layer. Optionally, during the application of the third press-down force, the amplitude of the mechanical vibrations can be set to a third value different from the amplitude applied during the second press-down force phase.

[0091] But the second press-down force and (where applicable) the third press-down force will typically be chosen such that the second outer structural layer is not penetrated by the connector. The second outer structural layer can remain intact without significant deformation.

[0092] In one set of embodiments, the connector comprises a head or other laterally protruding proximal feature. Such a laterally protruding feature can serve as a stop feature, i.e. once the head (or other laterally protruding proximal feature) physically contacts a distally facing shoulder of the first structural layer or a proximal surface of a second object that is joined to the first object by the connector, the energy input (in particular the mechanical vibrations) can be stopped.

[0093] The second object to be joined to the first object can optionally comprise a generally planar sheet portion having an opening. Such a sheet portion can be placed directly on the proximal surface of the first structural layer and in physical contact therewith. Alternatively, other portions such as a foil or film can be placed between the first object and the sheet portion. The opening through which the connector extends can be a through-hole or can be a laterally open recess (such as a slit or the like) after this process.

[0094] In embodiments, joining the second object to the first object can comprise at least one of the following measures:

[0095] - the second object around the opening has a section protruding away from the proximal facing plane of the first structural layer and a part of the connector (e.g. a peripherally laterally protruding feature (flange / head or the like) that comes into contact with the rim at the end of the approaching anchoring process, whereby the energy (e.g. vibrational energy) coupled into the connector causes a part of the thermoplastic material to become flowable due to the frictional heat generated between the rim and the thermoplastic material, the flowable material flows around the rim to at least partially embed the rim into the thermoplastic material. Depending on the geometry of the rim and the connector, an additional connection and sealing is thus achieved, essentially as described in PCT / EP2016 / 073422.

[0096] - the second object has a thermoplastic material in contact with the first structural layer, at least a portion of which is caused to flow relative to the first structural layer, whereby the structure of the surface of the first structural layer interpenetrates with the material of the first structural layer and / or forms a weld, such that an additional connection and possibly a seal is achieved.

[0097] - an adhesive is placed between the transversely protruding feature of the connector and the proximal surface of the second object and / or between the second object and the first structural layer. This adhesive can be a curable adhesive. Due to the mechanical vibrations coupled into the connector, the viscosity starts to decrease so that the adhesive can flow into the structure of the first object, the second object and / or the connector. Additionally or alternatively, the mechanical vibrations can accelerate the curing process. As a supplement or alternative to the curable adhesive, a thermoplastic adhesive can also be used.

[0098] - the flowable and re-solidifiable material of the connector causes it to form a form-fit connection with the second object, for example due to an opening in the second object which is not rotationally symmetrical, whereby a form-fit with respect to a rotational movement is created.

[0099] As an alternative to the head with the described type, the connector can be shaped so as to be inserted until the proximal surface of the connector is flush with the proximal surface of the first structural layer, or until at least a portion of the proximal surface of the connector is flush with the proximal surface of the first structural layer. The method can then comprise applying a second pressing force (if applicable and / or a third pressing force) until at least a portion of the proximal surface of the connector is substantially flush with the proximal surface of the first structural layer.

[0100] In an embodiment, the connector can have a proximally directed flange-like protrusion protruding radially outwards and be shaped so as to press against the edge of the remaining first structural layer in order to seal the connector with respect to the first structural layer.

[0101] In particular, the functional part of the connector, such as a fastener receptacle portion (which may, for example, comprise a thread hole open to the proximal side), is arranged so that it is distal to the proximal surface of the first structural layer, i.e. "inside" the first object, after the anchoring process.

[0102] In all embodiments, the method can comprise an additional step of maintaining the pressing force for a period of time after the step of stopping the energy transfer. This can be done at least until the flowable portion has lost its flowability, which typically occurs within a few seconds, depending on the dimensions of the connector and the thermal conductivity of the first object.

[0103] Generally, the connector can be a conventional connector for connecting a second object to a first object. To this end, as mentioned, the connector can for example comprise a head defining a distally facing shoulder, such that the second object with an opening is clamped between the first object and the head, through which the connector extends. Alternatively, the connector can comprise a connection structure, such as an internal or external thread, a bayonet connection structure, a structure allowing snap-in connection or any other suitable connection structure. In these cases, the connection structure can optionally be formed as a component of the connector that is not part of the thermoplastic liquefied material.

[0104] In addition or as an alternative to such conventional connectors, the connector can be an integral part of the second object itself having a dedicated function, for example the connector can be a connection pin protruding from a surface of the second object. The connector can also connect a rather small other object to the first object, for example a sensor or actuator or light source and / or other element, which other object can be integrated in the body of the connector.

[0105] In particular in a set of embodiments, the connector can comprise a functional structure in addition to the anchoring structure. Such a functional structure can be a connection structure defining a connection site, in particular relative to all dimensions (x, y, z). In particular, the functional structure, if the functional structure is a connection structure, the connection site can be off-center relative to the insertion axis such that the orientation of the connector around its insertion axis, typically the proximal-distal axis can be centered relative to the anchoring structure, determines the position and orientation of the connection site. Here, the functional structure is for example different from a fastening hole (with or without thread) coaxial with the axis, a proximally protruding coaxial pin or threaded rod, a head, etc. or any other common fastening structure of known fasteners.

[0106] The method can comprise anchoring the connector relative to the first object in a defined x, y and z position and orientation in the examples mentioned.

[0107] To this end, one or more of the following measures can be implemented:

[0108] - the tool applying the second pressing force comprises a position control that stops the process when the connector has reached the defined z position.

[0109] - the connector has a distally facing abutment face, the process stops if the abutment face is in abutment with a proximally facing corresponding structure of the first object. This can for example be the case if a mechanical resistance to further forward movement has reached a certain value (force control).

[0110] - the connector has a non-rotationally symmetric (about the insertion axis) guiding structure cooperating with a corresponding structure of the tool to define the orientation.

[0111] - the connector has a distal guiding structure which is non-rotationally symmetric with respect to the insertion axis and which cooperates with a corresponding non-rotationally symmetric positioning hole of the first object.

[0112] Additionally or alternatively, the connector can comprise a plate-like body portion from which the anchoring portion protrudes distally and which proximally of the anchoring portion is arranged the connection structure, wherein the body portion comprises a proximally facing coupling input face into which pressure is coupled during anchoring. In embodiments, the coupling input face can be arranged immediately proximally of the anchoring portion, i.e. the pressing-down force and the vibrational energy are coupled directly through the body portion without the need for a turn-around.

[0113] More generally, the functional portion comprising the functional structure can comprise a distally facing abutment structure, wherein the step of applying the second pressing-down force is carried out until the abutment structure abuts a proximal surface portion of the first object. The abutment structure can be a distal surface of the plate-like body portion or can be constituted by other features of the functional portion. The abutment portion defines a separation plane between the distal anchoring portion and the proximal functional portion.

[0114] Embodiments of the aspect of implementing the connection structure are not limited to embodiments of the first and / or second aspect, i.e. embodiments comprising no punching out of a portion of the first outer structural layer or breaking away from it and embodiments in which the first object is not necessarily a lightweight structural element having an inner lining layer.

[0115] In particular, embodiments of the aspect include embodiments in which the method comprises the step of opening a hole in the first outer structural layer before bringing the connector into contact with the first object, wherein the hole in the first outer structural layer can have a diameter which substantially corresponds to the diameter of the anchoring portion. In other words, while making a pilot hole is an option for all kinds of embodiments comprising the first and second aspect of the invention, further embodiments of the third aspect include embodiments in which the resistance against the connector piercing the first outer structural layer is not overcome by displacement but by locally removing the first outer structural layer.

[0116] The first object, the connector and, where applicable, the second object are broadly construed components (constituent elements), i.e. elements used in any field of mechanical engineering and manufacturing, such as automotive engineering, aircraft manufacturing, shipbuilding, building construction, machine manufacturing, toy manufacturing, etc. Typically, the objects and the connector will all be man-made objects. The use of natural materials such as wood-based materials is thus not excluded.

[0117] The flow portion of the thermoplastic material is a portion of the thermoplastic material which, during the process and as a result of the action of the mechanical vibrations, is caused to liquefy and flow. The flow portion need not be monolithic but can comprise portions separated from each other, for example at the distal end of the connector and at a more proximal location.

[0118] For exerting the counterforce of the pressure, the first object can be placed against a support, for example a non-vibrating support. According to a first option, such support can comprise a support surface in point-to-face contact with the connector, i.e. distal of the point. The first option can be advantageous because the combination can be implemented even if the first object itself does not have sufficient stability to withstand the pressure without significant deformation or even defect. According to a second option, however, the distal side of the first object can be exposed, for example by holding the first object along the side or the like.

[0119] In embodiments, the first object is placed against a support, without an elastic or yielding element between the support and the first object, so that the support rigidly supports the first object.

[0120] The inner lining layer can for example comprise a macroscopic dedicated structure with a large portion of hollow space, so that the density of the inner lining layer is rather small. For example, the inner lining layer can comprise walls extending vertically between the first and second outer structural layers (the walls extending parallel to the axis). In embodiments, such walls form a honeycomb structure.

[0121] More generally, in embodiments, the inner lining comprises a portion of material that is penetrable by the thermoplastic material. Therein, the step of flowing the flow portion comprises penetrating the material of the flow portion into the structure, thereby creating a form-fit connection between the connector and the first object after re-solidification. In case the inner lining layer comprises a thermoplastic material, for example as an impregnated material of a honeycomb structure, it is not excluded that a weld is additionally created by the thermoplastic material of the connector and the inner lining.

[0122] There are also lightweight structural elements that are suitable as first object for use in the present application and that have a thermoplastic wall structure, such as a thermoplastic plastic, for example a polypropylene honeycomb structure.

[0123] In addition thereto, the inner liner material suitable for the process is at least in the case of the method according to the application solid. It further comprises (real or potential) spaces through which the liquefied material can flow or be pressed down for anchoring. Alternatively, the penetrable material is able to create such spaces under the hydrostatic pressure of the liquefied thermoplastic material, which means that it can be non-penetrable or only to a small extent penetrable at room temperature conditions. This property (having a potential space for penetration) implies an inhomogeneity, for example, in terms of mechanical resistance. An example of a material having this property is a porous material, its pores being filled with a composite of a material that can be squeezed out of the pores, a soft material and a hard material or a homogeneous material, wherein the interface between the components is less adhesive than the force exerted by the penetrating liquefied material. Thus, in general, the penetrable inner liner material comprises an inhomogeneity in terms of structure ("empty" spaces such as pores, cavities, etc.) or in terms of material components (replaceable or separable materials). As mentioned above, a weld can be created between the material of the connector and the material of the inner liner layer. In these embodiments, the parts of the material of the inner liner layer that contribute to the weld do not remain solid but become flowable to an extent sufficient to form a weld.

[0124] This can optionally be supported by reducing the speed of the forward movement of the connector, for example, the forward movement is made possible mainly by the melting of the inner liner material (making it flowable), requiring almost no force, whereby it is possible to avoid the breaking of the inner liner structure.

[0125] The penetrable material can comprise a foam adhesive, such as a PU adhesive, between the structural layer and the inner liner and / or the inner liner itself can comprise spaces / pores.

[0126] In this context, the expression "thermoplastic material that can become flowable, for example, by mechanical vibration" or simply "liquefiable thermoplastic material" or "liquefiable material" or "thermoplastic" is used to describe a material comprising at least one thermoplastic component that, when heated, in particular when heated by friction, i.e. when arranged on one of a pair of surfaces that are in contact with each other and move vibrationally relative to each other, becomes a liquid (flowable), wherein the frequency of the vibration has the properties as described above. In some cases, for example, if the connector has to carry a large load, it can be advantageous if the material has an elastic modulus greater than 0.5 GPa. In other embodiments, the elastic modulus can be lower than this value.

[0127] Thermoplastic materials are well known in the automotive and aerospace industries. For the purposes of the method according to the application, known thermoplastic materials that are particularly suitable for these industries can be used.

[0128] The thermoplastic material suitable for the method according to the application is solid at room temperature (or at the temperature at which the method is carried out). It preferably comprises a polymeric phase (in particular based on C, P, S or Si chains) which above a critical temperature range (for example by melting) is transformed from a solid state into a liquid state or flowable, and when cooled again below the critical temperature range (for example by crystallization) is re-transformed into a solid material, whereby the viscosity of the solid phase is several orders of magnitude (at least three orders of magnitude) higher than the viscosity of the liquid phase. The thermoplastic material will typically comprise a polymeric component which is not covalently cross-linked or cross-linked, the cross-linking bonds being reversibly opened upon heating to or above the melting temperature range. The polymeric material can also comprise fillers, for example fibrous or particulate materials, which do not have thermoplasticity or have a thermoplasticity comprising a melting temperature range which is significantly higher than the melting temperature range of the base polymer.

[0129] In this context, a material which is "not liquefiable" is a material which cannot be liquefied at the temperatures reached during the process, thus especially at the temperatures at which the thermoplastic material of the connector is liquefied. This does not exclude the possibility that the not liquefiable material can be liquefied at temperatures which are not reached during the process, typically significantly higher than the liquefaction temperature of the thermoplastic material or at which the thermoplastic material is liquefied during the process (for example at least 80°C). The liquefaction temperature is the melting temperature of a crystalline polymer. For amorphous thermoplastics, the liquefaction temperature (also referred to herein as "melting temperature") is a temperature above the glass transition temperature at which it becomes sufficiently flowable, sometimes referred to as "flow temperature" (sometimes defined as the lowest temperature at which extrusion is possible), for example the viscosity of the thermoplastic material drops below 10 4 Pa*s (in embodiments, especially a polymer which is essentially free of fibrous reinforcement, below 10 3 Pa*s).

[0130] For example, the not liquefiable material can be a metal, such as aluminum or steel or wood or a hard plastic, for example a reinforced or unreinforced thermoset polymer or a reinforced or unreinforced thermoplastic, the melting temperature (and / or glass transition temperature) of which is significantly higher than the melting temperature / glass transition temperature of the liquefiable portion, for example at least 50°C or 80°C or 100°C higher.

[0131] Specific examples of thermoplastic materials are: polyetherketone (PEEK), polyesters such as polybutylene terephthalate (PBT) or polyethylene terephthalate (PET), polyetherimide, polyamide, e.g. polyamide 12, polyamide 11, polyamide 6 or polyamide 66, polymethyl methacrylate (PMMA), polyoxymethylene or polycarbonate polyurethane, polycarbonate or polyester carbonate, or acrylonitrile butadiene styrene (ABS), acrylate-styrene-acrylonitrile (ASA), styrene-acrylonitrile, polyvinyl chloride, polyethylene, polypropylene and polystyrene, or copolymers or mixtures of these.

[0132] In addition to the thermoplastic polymer, the thermoplastic material can also comprise suitable fillers, for example reinforcing fibers, such as glass fibers and / or carbon fibers. The fibers can be short fibers. Long fibers or continuous fibers can be used in particular for the part of the first and / or second object which is not liquefied in the process.

[0133] The fiber material, if any, can be any known material used for fiber reinforcement, in particular carbon, glass, Kevlar, ceramic, for example mullite, silicon carbide or silicon nitride, high-strength polyethylene (Dyneema), etc.

[0134] Other fillers which do not have a fiber shape are also possible, for example powder particles.

[0135] The mechanical vibration or oscillation suitable for embodiments of the method according to the application preferably has a frequency of between 2 and 200 kHz (even more preferably between 10 and 100 kHz, or between 20 and 40 kHz) and a vibration energy of 0.2 to 20 W per square millimeter of active surface. The vibration tool (for example an ultrasonic welding head) is designed, for example, such that its coupling output oscillates mainly in the direction of the tool axis (longitudinal vibration) and the amplitude is between 1 and 100 micrometers, preferably approximately 30 to 60 micrometers. Such a preferred vibration is produced, for example, by an ultrasonic device known, for example, from ultrasonic welding.

[0136] In this text, the terms "proximal" and "distal" are used to denote directions and positions, i.e. "proximal" means the side of the joint on which the mechanical vibration is applied by the operator or machine, while "distal" is the opposite side. The widening of the connector on the proximal side is referred to as "head" in this text, while the widening on the distal side is the "foot".

[0137] In this text, the term "under" generally means the distal space directed towards the layer, if the proximal side is defined as the side from which the layer is entered during the process. The term "under" is thus not intended to relate to the orientation of the earth's gravitational field during the manufacturing process.

[0138] The invention relates to a machine configured to carry out the method. The machine comprises an ultrasonic generator having a coupling output face, a mechanical vibration source configured to vibrate the ultrasonic generator, and a pressure mechanism configured to apply pressure by pushing the ultrasonic generator forward. The machine is configured and programmed to carry out the method claimed and described herein, including controlling the pressure in the manner claimed and described herein. BRIEF DESCRIPTION OF DRAWINGS

[0139] The following describes ways of implementing the invention with reference to the drawings. The drawings are schematic. In the drawings, like reference numerals indicate identical or similar elements. The drawings show:

[0140] Figures 1a to 1c is the configuration of the first object and the connector during different stages;

[0141] Figure 2 is the connector equipped with the second object;

[0142] Figure 3 is the ultrasonic generator;

[0143] Figures 4 to 7 is the distal part of the connector;

[0144] Figure 8 and Figure 9 are force versus time and force versus position diagrams for an embodiment of the process;

[0145] Figure 10 is a processing step to increase the indentation by a separate tool;

[0146] Figure 11 is that the first structure layer is destroyed instead of the indentation;

[0147] Figure 12 is a configuration with a cylindrical connector;

[0148] Figure 13 is a flow chart;

[0149] Figure 14 is the shape of the inner liner layer and possibly the punched edge in horizontal cross section;

[0150] Figure 15 is a variant of the flow chart;

[0151] Figure 16a and Figure 16b again in vertical cross section show the arrangement with the connector and the first object during different stages of the process;

[0152] Figure 16c shows a variant of the embodiment distinguished by Figure 16b the following features;

[0153] Figure 17 is an arrangement of a connector with a non-liquefiable component, a second object and a first object;

[0154] Figure 18a and Figure 18b is a further embodiment in two different stages;

[0155] Figure 19 , Figure 20a , Figure 20b and Figure 21 is an embodiment of a collapsible connector;

[0156] Figure 22 and Figure 23 are two further embodiments of a connector;

[0157] Figure 24 , Figure 25a , Figure 25b and Figure 26 is a further connector;

[0158] Figure 27 is a connector with a splicing portion, provided with a second object and a first object;

[0159] Figure 28 , Figure 29 , Figure 30 is an embodiment of a connector with a guiding portion;

[0160] Figure 31 is an arrangement with a connector with a guiding portion;

[0161] Figure 32 is a further connector;

[0162] Figure 33a is a further connector together with an ultrasound generator, and Figure 33b is a view of the connector of Figure 33a ;

[0163] Figures 34 to 38 further embodiments of a connector;

[0164] Figures 39 to 43 is a further connector;

[0165] Figure 44 is a further process diagram;

[0166] Figure 45 is an alternative lightweight structural element;

[0167] Figure 46 is a construction of an arrangement with a connector, a first object and an ultrasound generator in the process;

[0168] Figure 47 and Figure 48 Detail of a connector is shown;

[0169] Figure 49a and Figure 49b is another connector during two different phases of the process;

[0170] Figure 50 and Figure 51 show details of yet another connector and a variant thereof, respectively;

[0171] Figure 52 is an arrangement of a connector and an ultrasonic wave generator;

[0172] Figure 53 and Figure 54 is a variant of an ultrasonic wave generator;

[0173] Figure 55 is another arrangement of a connector and an ultrasonic wave generator,

[0174] Figure 56 is a view of yet another connector;

[0175] Figure 57 Detail of an arrangement with a connector, a first object and an ultrasonic wave generator during the process is shown;

[0176] Figure 57a and Figure 57b show details of horizontal cross sections through different embodiments of the connector of Figure 57

[0177] Figure 58 and Figure 59 is yet another connector;

[0178] Figure 60 is a connector anchored in a first object;

[0179] Figure 61 is another connector during the process as well as an ultrasonic wave generator and a first object;

[0180] Figure 62 and Figure 63 show details of further connectors;

[0181] Figure 64 is a view of an embodiment of Figure 62

[0182] Figure 65 show details of yet another connector and a first structure layer;

[0183] Figure 66 is a bottom view (from the distal side) of yet another connector;​​

[0184] Figure 67 and Figure 68 show details of an arrangement comprising a second object during two different stages of the process;

[0185] Figure 69 and Figure 70 show details of an alternative arrangement comprising a second object during two different stages of the process;

[0186] Figure 71 show details of a connector; and

[0187] Figure 72 is a second object having a non-circular opening.

[0188] Figures 1a to 7 , Figures 10 to 12 , Figures 16a to 19 , Figure 20a , Figures 22 to 25a , Figure 26 , Figure 27 , Figures 30 to 32 , Figure 33a , Figure 35 and Figure 35 , Figure 40 , Figure 43 , Figures 46 to 55 , Figures 57 to 63 , Figure 65 , Figures 67 to 71 all show vertical cross-sectional or side views. Figure 14 , Figure 20b , Figure 21 , Figure 25b , Figure 39 , Figure 40a , Figure 40b , Figure 41 and Figure 42 show horizontal cross-sections, Figure 64 and 72 show plan views, Figure 28 , Figure 29 , Figure 33b , Figures 36 to 38 , Figure 56 and Figure 66 show other angle views. DETAILED DESCRIPTION

[0189] The construction in Figure 1A comprises a first object 1 which is a sandwich panel having a first structural layer 1.1, a second structural layer 1.2 and an inner liner 1.3 between these. The first and second structural layers can comprise a fibre composite material such as continuous glass or continuous carbon fibre reinforced resin. The inner liner can be any suitable lightweight material, for example a plastic or composite material or a honeycomb structure of paperboard.

[0190] A common inner lining structure is a honeycomb structure having walls forming a honeycomb structure extending substantially perpendicular to the plane of the structural layers between which the structure extends. For example, the inner lining layer of a lightweight structural element comprises a paper honeycomb, which is covered by a mixture of a polymeric material, such as polyurethane (PU), and reinforcing fibers.

[0191] The inner lining can comprise a barrier foil and / or a web and / or an adhesive layer at the interface of the structural layers. In particular, an additional adhesive can bind the structural layers 1.1, 1.2 to the inner lining. In one example, a slightly foamed adhesive is used on the polyurethane matrix. Possible holes in the adhesive can contribute to anchoring of the various embodiments of the invention. The orientation shown here is that the upper face denotes the proximally facing face. The connector 3 is bound from the proximal side to the first object 1.

[0192] The connector 3 comprises at least at its distal end a thermoplastic material. It can for example consist of a thermoplastic material. In Figure 1a The connector in the embodiment and the other embodiments described hereafter has a body or head 3.1 and a distally protruding tube portion 3.2 forming a distal stamped edge 3.4.

[0193] Figure 1a A step is shown in which the connector 3 is brought into contact with the first object before mechanical vibrations are started. The thermoplastic material is at a first temperature T1, which can for example correspond to room temperature.

[0194] Figure 1b A component is shown in which mechanical vibrations are coupled to the connector 3 after the step of applying the first pressing force. An ultrasonic generator 6 with a coupling output face 6.1 (see Figure 3 ) is used to couple mechanical vibrations and pressure into the connector 3 to anchor the connector into the first object. The counterforce of the pressing force is applied by a support (not shown, for example a non-vibrating support). The first pressing force, possibly assisted by the mechanical vibrations, acts to penetrate through the first structural layer 1.1. A punch-out 1.7 is created. For illustration purposes, Figure 1b A punch-out is shown which is initially offset in a proximally directed direction relative to the plane defined by the first structural layer 1.1, but in practice any initial displacement before the steps described hereafter can depend on the pressure or similar action within the first object 1.

[0195] As a result of the mechanical vibrations and the pressing force, the connector 3 is at a higher second temperature T2 at its distal end.

[0196] Thereafter, a second pressing force and mechanical vibrations are coupled into the ultrasonic generator. The combined action of the vibrations and the pressing force is that parts of the thermoplastic material become flowable and are pressed into the structure of the first object. The connector dimension is thus changed. After re-solidification, a form-fit connection is created.

[0197] Figure 1cThe assembly is shown near the end of the second pressing force phase. The punch-out 1.7 has been displaced towards the distal end, forming a compressed portion 1.4 of the inner liner material. The compressed portion 1.4 of the inner liner material, the other portions of the inner liner material 1.3 around the attachment site, and possibly a layer of foamed adhesive (if applicable, such as a PU adhesive) between the second structural layer 1.2 and the inner liner layer 1.3 are penetrated by a flow portion 3.8 of the thermoplastic material. The flow portion occurs due to the outer friction between the thermoplastic material, which absorbs mechanical vibration energy and heats the flow portion to a temperature at which it is flowable, and the inner friction within the thermoplastic material. After the energy input has stopped, the flow portion re-solidifies to create a form-fit connection between the material of the connector and the inner liner layer (if applicable, possibly including the adhesive layer) and, optionally, also between the material of the connector and the second structural layer 1.2.

[0198] The punch-out 1.7 can remain substantially intact and / or oriented approximately parallel to the plane defined by the structural layers 1.1, 1.2. Alternatively, it can break apart and / or can take an undefined orientation during the process. In either case, this can contribute to the mechanical stability of the connector anchoring.

[0199] Figure 2 An embodiment of the connector is shown, which, in addition to the connector described with reference to Figures 1a to 1c , has the following features:

[0200] - The body or head 3.1 is a head that defines an outwardly protruding flange 3.5 that defines a distally facing surface portion, whereby a second object 2 having a through hole can be clamped between the head and the first object to fasten the second object to the first object. Such a laterally protruding flange (or other laterally protruding shape) can additionally or alternatively be used for fastening the second object, also as a stop feature for the process.

[0201] - The proximally facing coupling input face has a guide indentation 3.6 that cooperates with a corresponding protrusion 6.6 of the ultrasound generator (see Figure 3 ) during the process step.

[0202] These two features are independent of each other, i.e. the connector can be implemented with both, with one of them, or without either of them.

[0203] Figure 4 An alternative distal end of the connector is shown. The punch edge 3.4 is formed by an outward taper of the tube section 3.2, instead of the inward taper shown in Figure 1a and 2 .

[0204] Figure 5A further distal end of the connector is shown. In contrast to the previous embodiments, the distal end of the tube section 3.2 does not form a closed contour but is interrupted, so that the distal section 3.7 of the tube section 3.2 comprises a distal crown feature.

[0205] Figure 6 An optional version of the distal section 3.7 is shown which is deformed during a second pressing force phase (and / or an optional third pressing force phase described hereinafter) to bend outwards (arrow).

[0206] To facilitate such deformation, the connector can be designed collapsible, as Figure 7 shown. To this end, the connector has a circumferential groove 3.9 which constitutes a systematic weakening at the location between the distal section 3.7 to be deformed and the rest of the connector.

[0207] Figure 8 The pressing force applied by the ultrasound waves as a function of time in a process of the type described herein is shown schematically. During the initial steps of bringing the connector into contact with the first object and the contact, the pressing force is zero or almost zero. Then:

[0208] - in a first pressing force phase A, a high pressing force is applied and optionally also mechanical vibrations until the first structural layer has been pierced.

[0209] - After this phase A, in a second pressing force phase B, the pressing force is greatly reduced in order to allow the distal part of the connector to slowly advance through the softer inner liner material, so that during this step sufficient vibration energy is absorbed for the liquefaction to start. During this phase B, the parameters of the mechanical vibrations can differ from those applied during phase A, for example, the amplitude can be smaller than in phase A, since the energy required during phase A is particularly large. However, it is also possible to maintain the same amplitude, and it is not excluded that the amplitude is increased during phase B to intensify the heating process during phase B (for example, if a position-dependent control of force and amplitude is chosen).

[0210] - Then, in an optional further phase C, for example if the distal end of the connector has not yet liquefied parts that reach the second structural layer and / or the adhesive layer between the second structural layer and the inner liner, the pressing force can be increased again. The transition between the second pressing force phase B and this third pressing force phase C can be continuous (as Figure 8 shown) or can be stepped. During the further phase C, the mechanical vibrations with an amplitude comparable to phase B or a different amplitude are still coupled into the connector.

[0211] - At a certain point in time shown in dashed lines in Figure 8 , the energy input by mechanical vibrations is stopped. However, the pressing force is maintained during a holding pressing force phase D. It is possible that during phase D, the pressing force is reduced compared to phase C (with Figure 8 andFigure 9 The pressing force is even increased to push the flow portion or parts thereof laterally (radially) out of the radial displacement.

[0212] - Between phase C and phase D, an optional further phase C` can comprise maintaining the mechanical vibration (with the same or a different amplitude as in phase C) and increasing the pressing force again once all parts of the distal end of the connector have become flowable, since there is no risk of pushing through the second structural layer anymore at this stage, and the additional pressing force can enhance the radially outward (lateral) movement of the flowable thermoplastic material into the inner liner layer, which is generally desirable to enhance anchoring after the material has re-solidified.

[0213] Figure 9 The pressing force is shown in relation to the position d of the ultrasound wave generator relative to the proximal-distal axis in the same process. The width of the peak represents phase A, which corresponds to the combined thickness and limit of the elastic-plastic material of the first structural layer before penetration. Figure 9 The features can be used to control the pressing force in a manner related to the ultrasound wave generator position.

[0214] Figure 10 An optional solution is shown in which the pressing force is applied at least partially by a separate tool 8 before the connector contacts the first object. If this step is carried out with a tool 8 having relatively shallow protrusions as shown in Figure 10 Depending on the toughness of the first structural layer 1.1, this can result in a deformation without breaking the first structural layer at all or only at defined locations, if the step is carried out with a tool 8 having relatively shallow protrusions as shown in

[0215] Alternatively, as shown in Figure 11 the tool can be a punch that punches through the corresponding part 1.7 of the first structural layer. Then, the tool applies the first pressing force. The arrow 1.5 shows a possible flow path of the thermoplastic material flow portion for the subsequent application of the second pressing force and the mechanical vibration step.

[0216] In either case and including all cases where an indentation with a side wall is added, the deformed part of the first structural layer 1.1 around the edge of the indentation caused by the tool 8 can bring additional stability against shear forces (in-plane forces).

[0217] Figure 12 The principle that the connector 3 does not need to have a tube-shaped section is shown very schematically. Rather, the ideal shape can be chosen depending on parameters like the strength of the first object and the first structural layer, the connector material, etc. Among the possible shapes, the connector 3 has a flat end as shown in Figure 12 Figure 12 ​A connector with a simple revolved cylindrical shape is shown. The punched edge 14 can consist of an edge defining a flat distal end.

[0218] Figure 13 A process diagram of a method of anchoring a connector in a lightweight structural element is shown. The diagram shows the application of force 11 and vibration power 12 in relation to time. During an initial phase A, a portion of the first outer structural layer is punched out. The destruction of the relatively hard first outer structural layer requires a high force and a high vibration power. In a subsequent phase B, the punched out portion of the first outer structural layer is displaced, and more energy is coupled into the connector to make the thermoplastic material flowable. In this phase B, the required force is smaller, and the vibration power can also be smaller than in phase A. When the distal end of the connector (the portion of the connector that has started to become flowable and is deformed by the previous pressing) approaches the second structural layer, the required force increases again (phase C). In addition, the vibration power can optionally be selected to be higher in phase C than in phase B. As a further alternative, as shown in Figure 13 , the vibration power can be adjusted during phase B and / or phase C to e.g. include a plurality of peaks 12.1 as schematically shown. During an optional final phase (phase D, after pressing), the vibration power can be turned off, but the pressing force is maintained or even increased until the flowable portion has at least partially re-solidified.

[0219] Modifications to the process can be made. For example, in some embodiments, after phase A, the vibration can be turned off completely for a period of time, e.g. during the advancement of the connector to the first object. In addition or alternatively, the adjustment during phase B can include turning the vibration source on and off.

[0220] In particular, if the connector includes a proximally located collapse zone as previously mentioned and described in detail with reference to the Figure 7 , Figure 19 , Figure 23 , Figures 40 to 43 , Fig. 49, Figure 50 and other detailed descriptions, then in some embodiments it can be advantageous if the energy input is stopped for a period of time before phase C, whereby the distal flowable portion can re-solidify, so that when the energy input is resumed, the vibration is concentrated in a more proximal area, e.g. the area between the openings (see e.g. Figs. 49 and 50), thereby causing the desired collapse. Figure 49a , Figure 50

[0221] As Figure 14 ​As illustrated, in some embodiments, the inner liner has a honeycomb structure or other structure consisting of vertical walls (walls perpendicular to the structural layers). In such embodiments, the shape and size of the stamped edge 3.4 can be selected to press against the wall at multiple points 22. Thus, the stamped edge cuts through the wall and / or causes the wall to collapse. The collapsed wall can create an undercut structure, which helps anchor the connector after the thermoplastic connector material has interpenetrated through it after being liquefied and re-cured.

[0222] In particular, the cross-sectional area of ​​the connector at its distal end (e.g., the area surrounded by the stamped edge) can be at least approximately the unit size of the structure, so that the placement of the connector is independent of the structure, and the stamped edge will contact the wall at multiple points.

[0223] Figure 15 Show Figure 13 A variation of the process diagram. In this variation, a variation is shown for... Figure 13 Three distinct differences in the embodiment:

[0224] - After the first structural layer has been pierced, the vibration is shut off during the advance phase (phase B or at least the start of phase B).

[0225] - Vibration power 12 increases at the end of approach phase B.

[0226] -Force11 has multiple time-dependent peaks, which are generated by the discrete structure of the liner layer encountered at the far end.

[0227] Figure 16a An embodiment of the connector is shown, which is configured to pass through the first structural layer 1.1 but is configured to protect the second structural layer 1.2 even if the vertical position (z position) of the distal end cannot be precisely controlled.

[0228] For this purpose, connector 3, in addition to the thermoplastic body 31, also has a non-liquefiable component 32. The non-liquefiable component 32 may be, for example, metallic. The non-liquefiable component has a tube 32.1 that protrudes from the distal side of the body 31 and forms a distal stamped edge 3.4. Furthermore, it has an anchoring portion 32.2 extending into the interior of the body 31. The anchoring portion 32.2 is shaped such that, when pressed proximally, it tends to advance proximally relative to the body once the body material becomes deformable. However, the anchoring portion will cause an energy concentration effect and therefore an initial energy density at the distal stamped edge 3.4 that is higher than at the proximal end of the anchoring portion 32.2, especially if the first structural layer is relatively robust and requires high energy to penetrate and / or if the material of the body 31 is relatively soft.

[0229] Here, the shape of the anchoring portion 32.2 and thus the energy concentration properties thereof can be customized and designed according to its purpose. For example, if the thermoplastic material of the body 31 is a relatively soft, low-melting material such as polypropylene (PP), it can be advantageous for certain embodiments, for example if the material to be welded to the first object (which can also be PP) is desired at the end of the approach process. In such embodiments and / or if the first structural layer is relatively robust, the anchoring portion can have a relatively blunt proximal structure (with limited energy concentration effect), whereas for a more robust body material and a more weak first object material, the energy concentration properties of the anchoring portion can be selected to be more pronounced.

[0230] In the initial phase, the material of the body 31 will be robust, and when the pressing force and the vibrations are coupled into the connector, the pressing force and the vibration energy can be applied to the interface between the punch edge 3.4 and the first structural layer 1.1, whereby the first structural layer is punched. The process will also cause energy to be absorbed by the non-liquefiable component 32 and at the interface between the body 31 and the component. Thus, when the connector is pressed further into the sandwich panel 1, an inner flow portion 3.10 is formed around the non-liquefiable component 32 in addition to the flow portion 3.8, whereby the non-liquefiable component is pushed proximally relative to the body 31 when the connector is pressed further forward towards the distal end. This is shown in Figure 16b . The length of this portion ( Figure 16a of the tube in 16b) and the geometry of the anchoring portion can be situated in such a way that the non-liquefiable component is completely retracted into the body when the distal end of the connector reaches the second structural layer 1.2, so that in this case the connector can no longer be punched.

[0231] Figure 16c Variations of the embodiment of Figure 16b are shown by the following features:

[0232] - the liquefiable component instead of the block of liquefiable material has a tube portion and a circumferential groove 3.9, whereby the embodiment of Figure 7 can collapse.

[0233] - the anchoring portion is shaped to have a dilatation effect, i.e. it is shaped to exert an outwardly directed pressing force on the liquefied or not yet liquefied thermoplastic material when pushed proximally relative to the liquefiable component. This is shown by the arrows in Figure 16c .

[0234] These features, which can be implemented independently of one another, all contribute to the creation of a proximal liquefaction zone, i.e. the flow portion of the thermoplastic material will include a portion located proximally (e.g. immediately proximal to the distal end of the first outer structural layer) and will displace the respective portion of the flow portion radially outwards, whereby the anchoring (immediately proximal to the distal end) of the first structural layer is more robust, for example by means of a rivet effect.

[0235] Figure 17 A variant of this concept is shown, wherein the non-liquefiable component is a tube head of the tube portion 3.2.

[0236] Figure 17 Also shown is the principle of a connector with a flange 3.5, which is shaped to be suitable for fixing a second object 2 (e.g. a metal sheet or the like) to the first object 1. More details about the possibilities of this concept are described hereinafter with reference to Figure 27 and Figures 67-72 .

[0237] Figure 18a and Figure 18b Further alternatives of measures to protect the second structural layer from being pierced are shown. Only the tube portion 3.2 of the connector is very short, so that the depth d of the volume enclosed by the tube portion 3.2 is equal to or smaller than the thickness of the first structural layer. Thus, the punch-out portion 1.7 fills the volume, thereby protecting the punch edge 3.4, i.e. the part against which the connector can be pressed, from the punch edge. Figure 18b .

[0238] A further possibility is to collapse the distal end of the thermoplastic connector 3, which carries the punch edge 3.4. Figure 19 A connector with a tube portion with a circumferential groove 3.9 is shown, wherein the thermoplastic material in the vicinity of the groove 3.9 collapses once it is sufficiently deformed after the first heat input.

[0239] Figure 20a A possible concept of a connector with a leg portion 3.22 which deforms outwardly is shown schematically, which becomes able to deform (in particular outwardly) after the initial softening of the first structural layer. Figure 20b A possible alternative cross-section through the distal portion of a connector with a leg portion along Figure 20a the mid-plane B, C - B, C is shown. Figure 21 A possible alternative cross-section through the distal portion of a connector with a deformable leg 3.22 is shown. Figure 22 A concept involving the principle with two leg portions 3.22 is shown, wherein the arrows show the direction of deformation after the initial softening.

[0240] Figure 23 An example involving the combination of the principle that the non-liquefiable component 32 is pressed down towards the proximal side relative to the liquefiable component 31 during the process and the principle of separating the legs 3.22, wherein the legs belonging to the connector body 31 are separated via a retraction movement of the non-liquefiable component 32 is shown. To this end, the non-liquefiable component of the end portion is conical towards the proximal side (as shown in Figure 23 ) or has other ramp-like features which are able to exert an outwardly directed force on the liquefied or not yet liquefied thermoplastic material.

[0241] In Figure 23In embodiments of the application, the non-liquefiable component 32 does not pierce, i.e. it has a distally facing structure that does not cut into the first structural layer.

[0242] As a supplement or alternative to the leg opening, such non-liquefiable portions that displace the liquefiable material radially outward can have other effects and purposes. Namely, optionally in combination with a collapse structure Figure 23 illustrated by the circumferential groove 3.9) the non-liquefiable component 32 helps to liquefy the thermoplastic material of the liquefiable component 31 not only at the distal end but also more proximally, e.g. immediately distal to the first outer structural layer 1.1. As a supplement or alternative to the auxiliary liquefaction, the non-liquefiable component can generate an outward displacement force on the liquefied thermoplastic material of the liquefiable component 31 so that the respective portion of the flow portion will be displaced radially outward, thereby making the anchoring, in particular with respect to the first outer structural layer, more robust.

[0243] Figure 24 illustrated by the circumferential groove 3.9) the non-liquefiable component 32 helps to liquefy the thermoplastic material of the liquefiable component 31 not only at the distal end but also more proximally, e.g. immediately distal to the first outer structural layer 1.1. As a supplement or alternative to the auxiliary liquefaction, the non-liquefiable component can generate an outward displacement force on the liquefied thermoplastic material of the liquefiable component 31 so that the respective portion of the flow portion will be displaced radially outward, thereby making the anchoring, in particular with respect to the first outer structural layer, more robust. Figures 20a to 22 Variation of the embodiment of the application, wherein the connector has a cross section that is tapered.

[0244] Figure 25a and Figure 25b Illustrated is an example of an embodiment of a leg and stabilizer 41 (such as a ring of non-liquefiable material) that is relatively flexible from the outset. The ring (or other stabilizer) will initially be located near the distal end of the connector and will be displaced backwards (arrow) by introducing the connector into the first object, in particular by abutting the proximally facing surface of the first structural layer.

[0245] Figure 26 Illustrated is the possibility that the connector can be anchored in the lightweight structural element from the side, i.e. from the transverse direction. In particular, as illustrated in Figure 26 The lightweight structural element can be formed along its edges such that one of the outer structural layers is bent vertically and towards the other outer structural layer and is connected to each other. Thus, the bent outer structural layer Figure 26 The first outer structural layer 1.1 in the example illustrated has an edge termination section 1.11, by contacting the termination section 1.11 and by a substantially horizontal pressing force (as illustrated in Figure 26 The connector 3 can be pressed into the lightweight structural element. This embodiment requires a sufficiently stable inner liner layer 1.3 to exert a counterforce to the second pressing force that is sufficient by the action of the energy input to make the thermoplastic material of the connector flowable. If the counterforce of the inner liner layer 1.3 is not sufficient to accomplish a secure anchoring by this method, possible additional measures can be taken, such as a connector shaped as described with reference to Figures 16 to 25 or a connector provided with a collapse structure (of the type described later).

[0246] With reference to Figure 27A further principle is described. The connector 3 has a plug-in portion 3.28 distally of the flange 3.5, which is dimensioned to have a cross section slightly larger than an opening in the second object 2 to be fixed to the first object 1. However, the cross section of the plug-in portion is substantially larger than the cross section of the shaft and / or tube portion, which penetrates the first object during the process. The plug-in portion is pressed into the opening at the end of the approach process, wherein the mechanical vibration energy and the pressing force cause a tight connection between the plug-in portion and the second object.

[0247] The plug-in portion 3.28 can be ring-shaped and continuously compact. Alternatively, it can be composed, for example, by comprising a plurality of radially extending ribs, which, in addition to serving as plug-in portion, can have energy-directing properties. This is particularly meaningful in the case of a structure layer which is not uniformly dense but, for example, consists of a consolidated fleece / polypropylene (PP) / glass fiber composite.

[0248] The tight connection between the plug-in portion and the second object and / or the corresponding tight connection between the plug-in portion and the first structure layer can comprise one or more of the following: a press fit, a polymer-polymer welding connection, an interpenetration of the second object / first structure layer material by melting and re-solidification of the material of the plug-in portion.

[0249] In Figure 27 , the connector 3 is shown to consist of a thermoplastic material.

[0250] In either case, the connection between the plug-in portion and the second object 2 can result in a seal between the proximal side of the second object and the distal side of the second object.

[0251] For many applications, the connector needs to be positioned relatively precisely with respect to the first object when anchored in the first object. Figures 28-31 A first possibility for doing so is shown.

[0252] In addition to the tube portion 3.2, the distal edge of the connector forms a punched edge 3.4, shown in Figure 28 , 29 The connector 3 shown in Figure 31 , for example, comprises a central guide portion 3.30. The guide portion 3.30 protrudes further distally than the plane defined by the punched edge 3.4. Thus, when the connector is positioned with respect to the first object so that the distally facing surface portion (punched edge) contacts the first structure layer and before the pressing force begins (and in most embodiments also before the mechanical vibration begins), the guide portion can be introduced into a guide hole 1.10 in the first structure layer 1.1, for example as shown in

[0253] Since the guide hole 1.10 and the guide portion 3.30 together define the position of the connector relative to the first object, the ultrasound generator 6 does not need to be positioned accurately and does not need to have a shape that fits the shape of the connector 3, for example as shown in Figure 31

[0254] The guide portion 3.30 can at least partly become flowable during the process and cause an interpenetrating structure of the inner liner and / or can cause a collapse and / or deformation. To this end, the guide portion 3.30 can be thermoplastic. Additionally or alternatively, the guide portion can be mounted in a way that it is only relatively weakly connected to the rest of the connector, so that it can be disconnected / loosened by energy input during the process. For example, in the embodiment of Figure 28 , the guide portion 3.30 is connected to the mounting portion 3.31 in a way that it is not directly supported by the body 3.1 of the connector against axial forces, so that sufficient axial forces can shear off the guide portion 3.30. In the embodiment of Figure 29 , the guide portion 3.30 is a slit so that it comprises two deformable legs that are separated. In the embodiment of Figure 30 , the slit configuration (not visible in Figure 30 ) and / or the fastening hole 3.13 that extends into the guide portion 3.30 cause a local weak point towards the proximal end of the guide portion.

[0255] In embodiments, the guide portion and the corresponding guide hole can be configured to have a non-rotationally symmetric cross section, so that not only the position but also a discrete number of possible orientations is defined. Figure 28 An example of a guide portion that is rotationally symmetric around a proximal-distal axis is shown.

[0256] Figures 28 to 30 A further optional feature of the connector according to the invention is shown. Namely, the connectors all have a fastening hole 3.13 that extends inward from the proximal end. Depending on the configuration, the fastening hole 3.13 can be a through hole Figure 28 and Figure 29 or a blind hole Figure 30 . The fastening hole 3.13 can be used for a screw or other fastener to be inserted therein (including a fastening portion of a further object to be connected to the first object), whereby the connector can serve as an anchor for connecting a further object to the first object. This can optionally engage the flange previously discussed that can be used to secure the second object to the first object. The fastening hole 3.13 can optionally include a thread or other fastening structure.

[0257] ​A second alternative for precisely positioning the connector relative to the first object comprises precisely positioning the sonotrode (or a separate guiding tool) relative to the first object and guiding the connector by the sonotrode (or correspondingly the separate guiding tool) during this process. The principle of guiding the connector by the sonotrode is shown in Figure 2 and Figure 3 . Figure 32 A further example of a connector with a guiding indentation 3.6 and a sonotrode 6 with a corresponding guiding protrusion 6.6 is shown. In the embodiment of Figure 32 the guiding indentation 3.6 also has a fastening hole 3.13 proximally thereof. It is also possible that the fastening hole is alternatively applicable as the guiding indentation.

[0258] Embodiments of Figure 32 have other special features independent of the principle of the accommodation indentation. The connector 3 has a head or body portion 3.1 with a guiding indentation 3.6 and a distally protruding tube portion 3.2 forming a distal punch edge 3.4. In contrast to the embodiment of Figure 2 for example, the connector also comprises a fastener accommodation portion 3.12 formed as a central distal protrusion extending distally from the head or body portion 3.1. In the fastener accommodation portion 3.12 there is a fastening hole 3.13. The fastening hole can be used for inserting a fastener, such as a screw or pin. Depending on the properties of the fastener used and the material properties of the connector, the fastening hole can comprise a corresponding structure, for example an internal thread.

[0259] Instead of or in addition to the fastening hole, the connector can have other fastening features like male fastening structures (like screws or the like) instead of female fastening structures. The corresponding sonotrode used has a corresponding indentation accommodating such fastening structures to avoid direct coupling of vibrations into the fastening structures.

[0260] The connector 3 as shown in Figure 33a and Figure 33b is a connector example comprising a connection structure defining the connection position (especially the connection position defined relative to all dimensions (x, y, z)) in addition to the anchoring structure (which comprises the flowable thermoplastic material during this process as well as the punch structure (if applicable)). The connection structure in the shown embodiment is constituted by a connection pin 3.16 integral with the anchoring structure.

[0261] The connection structure, in the illustrated embodiment a connection pin 3.16, is arranged in particular transversely. This means that the connection structure 3.16 is not arranged symmetrically with respect to the insertion axis 20, but is arranged eccentrically with respect to the axis 20. The insertion axis 20 is the axis along which the pressing force is applied during insertion and along which at least predominantly movements take place during insertion. The insertion axis 20 is usually centered with respect to the punch-out portion. The axis is thus defined in particular by the tube of the connector or other structure defining a punch-out or interrupted contour and / or a piercing point.

[0262] The position of the connection site thus depends on the angle of rotation about the axis 20. Thus, in contrast to most of the previously discussed embodiments, not only the position but also the orientation has to be defined when the corresponding connector is positioned and anchored in the first object.

[0263] Examples of corresponding connection structures are structures projecting away from the anchoring structure in a defined direction, such as a pivot of a hinge or the like, a structure for clamping other items thereon, an anchoring piece for a screw connection, etc.

[0264] Figure 33a and Figure 33b The connector 3 comprises a plate-like body portion 3.1 defining a distally facing abutment face 3.18. From the abutment face 3.18, a tube portion 3.2 with a distal punch edge 3.4 projects distally. Towards the proximal side, the connector comprises a base wall 3.15 from which a connection pin 3.16 projects transversely. The base wall is arranged eccentrically with respect to the axis 20. Furthermore, the connector comprises a plurality of reinforcement walls 3.14 extending perpendicularly to the base wall 3.15 and enhancing the mechanical stability with respect to forces acting on the connection pin.

[0265] The distally facing abutment face defines the z-position of the connection structure, after which the pressing force is applied until the abutment face 3.18 abuts against a proximally facing surface portion of the object.

[0266] In the embodiment of Figure 33a and Figure 33b The connector 3 in the embodiment of Figure 34 and Figure 35 may be, for example, a mounting seat of an automotive parcel shelf.

[0267] The ultrasonic generator 6 for anchoring the connector can be shaped to fit the shape of the connector. In particular as illustrated in Figure 33a The connector can be shaped to be struck from the proximal side by engaging between the reinforcement walls 3.14 and the base wall 3.15. Additionally or alternatively, the connector 3 can also be provided with a projecting flange 3.5, as illustrated in Figure 33aAs shown by the dashed line. The ultrasonic generator is directly coupled to the main body 3.1 between the walls. The arrangement of the ultrasonic generator with indentations (if necessary) for reinforcing the (multiple) walls has the advantageous characteristic of directly coupling the pressing force and vibration into the anchoring part.

[0268] In embodiments including a connection portion, the position and / or orientation of the connection portion depends on the orientation of the connector about its axis 20. It may be necessary to guide the orientation of the connector during anchoring because the connector may experience some uncontrolled torsional movement due to vibration input during insertion. Figure 33a and Figure 33b In some embodiments, the base wall 3.15 and / or the reinforcing wall 3.14 may be used in conjunction with the corresponding shape of the ultrasonic generator, whereby the orientation of the ultrasonic generator defines the orientation of the connector.

[0269] Additional or alternative land, such as Figure 34 As shown (where the right figure shows an enlarged top view of guide indentation 3.6), the connector and ultrasonic generator may include corresponding non-circular symmetrical guide structures, such as rectangular guide protrusions of the ultrasonic generator, which engage the corresponding guide indentation 3.6 of the connector. Other shapes of guide protrusions and guide indentations may include any known shape for screw heads, including hexagonal, star, etc.

[0270] Figure 34 An embodiment includes an annular base wall 3.15, from which a connecting pin 3.16 protrudes outward. The base wall conforms to, for example, a circular or rectangular profile, thereby defining a can-shaped structure with a can bottom defined by a connector body, during which an ultrasonic generator presses against the bottom.

[0271] like Figure 35 As illustrated, embodiments of the connection structure or other eccentric functional structures, other than the anchoring structure, are not limited to embodiments implementing the first and / or second aspects, the first aspect including displacing (maintaining contact) a portion of the first outer structural layer relative to the inner liner at the attachment site by applying a first pressing force. Figure 35 A connector with a proximal portion is shown, which is similar to Figure 34 The corresponding structure of the embodiment, but the base wall is not annular.

[0272] Independent of this, the anchoring structure includes, for example, an anchoring structure pin portion 3.17 that is pressed through the first structural layer and into the inner liner for anchoring.

[0273] exist Figure 35 In one embodiment, the pin portion 3.17 has a plurality of axially extending energy guides, namely radially protruding wings 3.19.

[0274] Figure 33 to Figure 35Embodiments of the application include the use of an ultrasonic generator adapted to the geometry of the connector. This is not always necessary. Figure 66 An embodiment is shown in which the body part 3.1 forms a substantially flat coupling surface for a universal ultrasonic generator.

[0275] Figure 66 Embodiments of the application have additional features which can be realized independently of or in combination with each other and / or with Figure 66 the other features shown in

[0276] The connector 3 has a plurality of cutting elements, namely two cutting elements. Each of these cutting elements consists of a tube part 3.2 with a distal punched edge.

[0277] The tube part(s) is not circular but has an approximately rectangular outer contour. In general, any cross section can be used which leaves a hollow space within the enclosing wall.

[0278] The distal punched edge is not sharp but blunt.

[0279] In addition to the cutting element(s), the connector has a process control abutment protrusion 3.71. In Figure 66 this abutment protrusion forms a tripod together with the cutting elements, so that the connector position is unambiguous and stable when the connector is in contact with the first structural layer.

[0280] Such an abutment protrusion 3.71 can collapse or melt during the subsequent process. It does not necessarily have to penetrate the first structural layer, i.e. it does not need to have any piercing properties.

[0281] In addition to stabilizing the connector at the initial stage of the process, it also dampens unwanted bending vibrations when the connector body 3.1 extends substantially transversely.

[0282] Figure 36 A connector is shown which is based on the principles described with reference to Figures 33a-35 the figures. In contrast to the embodiments of these figures, the connection structure is not a pin but a fastening hole in the base wall 3.15.

[0283] In the embodiment of Figure 37 instead of a plate-like body part and a wall (rib) shown in Figures 33a-36 the connector has a closed housing 3.31 which is either or both of itself eccentric with respect to the insertion axis or accommodates a functional structure which is eccentric with respect to this axis.

[0284] In Figure 37 the functional structure which is eccentric with respect to the axis (shown as a dotted line) is not the connection structure but another functional component. Figure 37Two components are shown very schematically in dashed lines within the housing. The functional structure can comprise sensors, antennas, light sources, cameras, acoustic transducers, etc.

[0285] Figure 37 The shown embodiment with a closed housing can be provided with means for coupling vibration energy from the proximally facing end face of the housing to the anchoring portion, e.g. the tube portion 3.2. Figure 56 An embodiment of a connector 3 is shown, which in the shown embodiment has a connecting pin 3.16, through which the tube portion 3.2 of the connector extends to the proximal end face of the connector. The housing therein can be open distally. If the housing is open distally, the abutment portion of the functional portion is constituted by the distal edge of the vertical wall of the housing.

[0286] Other solutions are possible for coupling vibration energy from the proximal end face into the anchoring portion, such as through a vertical reinforcing wall or other vertical structure of the housing.

[0287] Figure 38 Instead of having one tube portion with a punched edge, the connector can comprise a plurality of cutting elements. In Figure 38 , each of these cutting elements is constituted by a tube portion with a distal punched edge.

[0288] An embodiment of a connector is shown in Figure 6 , Figure 7 , Figure 19 , Figures 20a to 21 , Figure 23 and other figures, which comprises a distal section that is deformed, in particular collapsed outwards, in the process. Depending on the material composition and dimensions of the first object, in particular depending on the thickness of the distal section of the tube portion / connector and the thickness (proximal-distal extension) of the first object, control of this collapse can be an issue, measures can be taken to implement such control.

[0289] Additionally or alternatively, it can be desirable to ensure that the flow portion of the thermoplastic material not only penetrates the structure distally near the second outer structural layer, but also flows proximally to the first structural layer, first for increasing the interpenetration amount, then for creating a rivet effect. For example Figure 7 , Figure 16c , Figure 23 Embodiments are such embodiments that comprise measures for letting the thermoplastic material flow like this at a more proximal position.

[0290] Generally, the question of whether the flow portion flows proximally to the first structural layer or not depends on the specified dimensions, and in embodiments it can be desirable to influence this.

[0291] Figure 39 The shown embodiment of a connector is an example of a connector with a plurality of legs, but compared to Figure 20a ,Figure 20b and Figure 21 or also Figures 25a to 25b The leg 3.22 is initially connected by at least one bridge 3.23 which serves as a predetermined breaking point during the process.

[0292] In Figure 40 embodiments, the tube portion is stabilized by at least one stabilizer rib 3.21. Such a stabilizer structure can prevent the tube portion, which can optionally comprise a plurality of legs, for example as shown in Figure 39 or Figure 21 , from collapsing during the initial phase of displacing a portion of the first outer structural layer.

[0293] As also shown in Figure 40 , the stabilizer structure can also be shaped to exert an outwardly directed pressing force during the subsequent step of pressing the connector into the lightweight structural element. The arcuate concave profile in the example shown will cause such an outward pressing force when the connector is pressed into the inner liner material, as indicated by the arrow in Figure 40 .

[0294] Figure 40a A possible cross-sectional detail along the plane A-A of Figure 40 is shown, which shows that the tube portion 3.2 of the connector need not be circular in cross-section. Rather, in Figure 40a embodiments, the connector has an axially extending notch at the location where the stabilizer rib 3.21 is connected to the tube portion 3.2. Thereby, the thermoplastic material of the tube portion can be advantageously extruded outwardly by the directed pressing force.

[0295] Figure 40b A detail of a possible cross-section along the plane B-B of Figure 40 is shown. The circumferential groove 3.9 need not necessarily extend around the entire circumference, but can be interrupted, especially at the location where the stabilizer rib 3.21 is connected to the tube portion.

[0296] Figure 41 A possible horizontal cross-section through the connector is shown. The combination of a circular geometry and crosswise arranged stabilizer ribs 2.21 is especially stable.

[0297] Figure 42 A cross-section through an alternative anchoring portion is shown, which does not have circular symmetry, but rather an elliptical cross-section. In such embodiments, especially the stabilizer structure, like the stabilizer ribs 2.21 arranged as shown in Figure 42 , can be advantageous.

[0298] Figure 43The connector is shown with a stabilizer rib 3.21 pointing towards the distally facing tip 3.25 or edge, so that the inner liner material that is penetrated by the connector during the procedure is forced in the direction of the arrow, thereby exerting an outwardly pressing force on the tube portion 3.2 or leg, respectively.

[0299] Figure 57 The connector has a cross-sectional step 3.52 formed by an inwardly facing shoulder 3.51 that defines a collapse zone instead of the previously described slot. The collapse zone defined by the cross-sectional step instead of the slot can have the advantage of being easier to manufacture by the injection molding process.

[0300] Similar to Figure 40 the embodiment of Figure 57 the connector 3 has at least one reinforcing rib 3.21. Figure 57a and Figure 57b Two possible alternative cross-sections through Figure 57 the face A-A are shown. However Figure 57a the embodiment includes a notch at the location where the reinforcing rib connects to the tube portion 3.2, in Figure 57b the embodiment the connector has an outward protrusion at the respective location. Thus in Figure 57a the embodiment there is mainly a benefit for outward collapse at a location different from the location of the intersection of the reinforcing rib with the tube portion 3.2, whereas in Figure 57b the embodiment there is (also) a benefit for outward collapse at this location.

[0301] Figure 57 It is also shown that the principle of a relatively hard displacement portion 1.7 (punch-out portion) can help to exert an outward pressing force on the thermoplastic material at a more proximal location, especially at a location immediately distal of the first outer structural layer 1.1. That is, the displacement portion that is pressed into the inner liner material distally will exert a counter force on the connector. If the connector is suitably shaped, for example by a reinforcing rib 3.21 that is concave as shown in Figure 57 this can lead to a splitting effect as shown by the arrow in Figure 57 .

[0302] Figure 44 Additional or alternative solutions for the connector shape are shown, process parameters can also be used to help liquefying the thermoplastic material portion not only at the distal end but also more proximally. Figure 44The time-dependent vibration power 12 is schematically shown. During an initial phase A, the vibration power, and thus the amplitude, is high until the connector is forced through the first outer structural layer. Then, in a second phase B, the power is greatly reduced. Thus, the process is slowed down and the material at the distal end is allowed to liquefy and flow, so that it becomes less sharp and slows down or even stops its advancement distally, by which the energy absorption more proximally is enhanced. Alternatively, in an intermediate segment B` (dashed line), the energy input between the first and second phase is stopped, so that the material at the distal end can even re-solidify to some extent.

[0303] Figure 45 A first object is very schematically shown as an alternative, the first object as a lightweight structural element has a smaller thickness and an increased density of the inner liner 1.3 than the first object described before.

[0304] There is for example a lightweight structural element having an inner liner as a lightweight porous structure comprising a thermoplastic material. For example, the lightweight structural element.

[0305] There is for example a lightweight structural element having a fleece-like outer structural layer (e.g. wood / polypropylene (PP) or glass fiber-PP composite) and having a PP structure (e.g. a PP honeycomb structure) as an inner liner.

[0306] Figure 46 It is shown that in some lightweight structural elements having a reduced thickness of the outer structural layer, the first outer structural layer 1.1 can locally deform near the location where the connector breaks through it. To compensate for such deformations, the connector can optionally have a head 3.42 with a distally facing concave surface.

[0307] Fig. and 48 show a proximally distally facing fusion edge 3.44 provided for the connector, which is positioned and shaped to press against the first outer structural layer at the end of the approach to the anchoring process, thereby becoming a welded joint of the liquefied and interpenetrating structure of the first outer structural layer and / or fusion with the material of the first outer structural layer and / or the inner liner.

[0308] As an additional or alternative option, in embodiments comprising a thermoplastic inner liner, the anchoring can comprise a weld between the thermoplastic material of the connector and the thermoplastic material of the inner liner in addition to the interpenetration of the structures.

[0309] Figure 49a and Figure 49bAnother embodiment of the collapsible connector is shown, both in the initial stage and after energy input. The connector includes multiple openings 3.45 in the proximal region. The fact that the connector material is weaker between the openings will result in an energy concentration effect. If the internal friction within the thermoplastic connector material is high enough, liquefaction will begin in the region of the openings, except at the distal end. Therefore, the flow portion 3.8 has a portion at the distal end and also a portion at the height of the openings. If the openings 3.45 are arranged accordingly, this can be used to induce radial flow immediately adjacent to the distal side of the first structural layer 1.1. Figure 49b The location of the first structural layer 1.1 after this process is shown by a dashed line.

[0310] As described above, in the embodiments, the process can be implemented such that, after the initial stage, the distal flow portion is allowed to re-solidify by stopping the energy input after the connector has reached a certain position, and that in a further step, the energy input is restarted, thereby concentrating the energy input in the area between the openings 3.45, so that it begins or continues as Figure 49a and 49b The collapse shown.

[0311] Figure 50 A variant of connector 3 is shown, wherein an opening 3.45 is arranged in a collapsed region 3.46, and a force transmission region 3.47 is present in the collapsed region 3.46. The force transmission region includes a stamped edge 3.4 facing the distal side, which breaks through the first outer structural layer in the initial stage of the process.

[0312] Figure 51 The schematic diagram illustrates the principle that the shape of the opening 3.45 (which could be a through hole) can be used to generate forces in the radial or circumferential direction. Figure 51 The cross-section of the opening shown at 3.45 degrees is rhomboid, making the axial direction ( Figure 51 The compressive force in the vertical direction generates a shear force in the direction perpendicular to the axial direction.

[0313] Figure 52 Showing something similar Figure 32 The connector embodiment of the example. Depending on the material strength of the relevant materials, the connector 3 with fastening holes 3.13 and / or other structures that require precise definition may present the challenge of ensuring that such precisely defined structures do not collapse during energy input.

[0314] Figure 52The arrangement of Fig. 1 shows a first possible solution to the problem. The ultrasonic generator 6 has the outstanding feature of a circumferential protrusion 6.11, whereby the ultrasonic generator is pressed against only the outer peripheral portion of the connector 3, which has a lateral position corresponding to the position of the tube portion 3.2, so that the pressing force is coupled into the connector only there, where it can be directly transmitted to the punched distal end. The central portion is not affected by the pressing force, so that the area around the fastening hole 3.13 can remain relatively stable.

[0315] In Figure 58 a variant of Fig. 2, the connector 3 has a joint 3.45 that connects the central portion made up of the fastener receptacle 3.12 and the outer peripheral portion including the tube portion 3.2. The joint is made up by a local thinning, so that some elastic deformation occurs between the central portion and the outer peripheral portion. The ultrasonic generator 6 acts only to the outer peripheral portion, so that the joint 3.45 decouples the central portion from the outer peripheral portion with respect to mechanical vibrations, i.e. mechanical vibrations will not essentially be coupled to the central portion, when the central portion encounters mechanical resistance of a displaced portion of the first structural layer, which encounters resistance of the compact inner lining layer.

[0316] With reference to the concept shown in Figure 52 and Figure 58 may be optional solutions to other embodiments and principles described herein, including but not limited to the embodiments and principles described with reference to Figures 28-31 .

[0317] Figure 53 An ultrasonic generator for Figure 52 and Figure 58 is shown, which has a central guiding protrusion 6.6 in addition to the circumferential protrusion 6.11, which fits a dedicated guiding structure of the fastening hole or the connector. Such a guiding protrusion 6.6 has the effect of stabilizing the indentation it engages, e.g. the fastening hole, in addition to guiding the connector with respect to the ultrasonic generator.

[0318] Figure 54 A further variant of the ultrasonic generator 6 is shown. Figure 52 A variant of the ultrasonic generator of Fig. 3 has a central pushing portion 6.12, which is connected to the main body of the ultrasonic generator by a spring 6.13. It is thus equipped for applying a controllable pushing force on the central portion of the connector, which is defined by the spring constant. The pushing force is thus applied not only by the contact surface but also on the central portion. This can be particularly advantageous if, during the application of the second pushing force, it is to be expected that the central portion will be subjected to considerable resistance. The pushing force on the central portion can at least to some extent balance this resistance.

[0319] However, the central pushing portion 6.12 of the spring is essentially decoupled from the ultrasonic generator body, as it does not transfer mechanical vibration energy. Thus, the central portion of the connector, with the fastening hole or other precision positioning structure, is gently pushed into the first object together with the peripheral portion, while avoiding unnecessary energy input and liquefaction of the central portion.

[0320] Figure 55 Variants in Figure 52 and 53 have other features in addition to the features of the embodiments with the optional guiding protrusion 6.6. Namely, in some embodiments the connector needs to have a defined proximally facing surface, for example if a screw or other fastener is to be engaged with the fastening hole, where the distally facing fastener head surface abuts this proximally facing surface. Similarly, other elements that are to be fixed to the fastener and thereby to the first object can rest on the proximal fastener surface, which then needs to be precisely delimited. However, during the process of pressing down and coupling energy into the connector, some of the material of the connector melts in direct contact with the ultrasonic generator 6, which can lead to a bulge near the contact surface between the ultrasonic generator and the connector, which makes it impossible to precisely delimit the proximal end of the connector.

[0321] Thus, Figure 55 the connector 3 of the embodiments in has a proximal protrusion 3.41 around the fastening hole 3.13, which has a proximal end face. The contact surface between the ultrasonic generator and the connector, which is defined by the peripheral protrusion of the ultrasonic generator, is distal to the proximal end face of the proximal protrusion 3.41. Thus, a bulge formed close to this contact surface has no effect on delimiting the proximal end of the connector.

[0322] Figure 55 In , the dashed line shows the position of the first structure layer 1.1 after the process.

[0323] Figure 55 Generally, in some embodiments the process can be carried out until the upper (proximal) surface of the connector is flush with the proximal surface of the first structure layer, or as shown in

[0324] In embodiments, depending on the properties of the first structure layer 1.1, the first structure layer will fold inwards around the hole formed during the process. Such a protruding flange 3.5, shown for example in Figure 16c , Figure 23 , Figure 30 , Figure 40 or Figure 50 may be used instead as a reference in such embodiments. Figure 2The stop feature shown is also pushed into the first object 1 and simultaneously used to close the hole formed. In embodiments, this closure can be such that the flange 3.5 can act as a sealing portion.

[0325] Figure 59 Further embodiments of the connector 3 are shown and the possible position of the first structure layer 1.1 after the process is shown in dashed lines. As Figure 59 It is clear that the functional components of the connector after the process are located distally of the proximal surface plane of the first object, i.e. "inside" the first object. Figure 59 The functional components in the first object 1 include the fastener receiving portion 3.12, but the teaching can also be applied to any other functional component.

[0326] Figure 59 A further special feature of the embodiment of the connector 3 is the shape of the distal end of the tube portion 3.2, which is independent of the other features of this embodiment and is also an option for other types of connectors. That is, in contrast to the previously described embodiments, the distal end forming the punched edge is not a sharp edge but a blunt edge 3.4`. In Figure 59 In the embodiment shown, the distal end has a flat end face forming a blunt punched edge 3.4`. It has been found that for some materials of the first structure layer, the blunt punched edge is sufficient for the punching and it even advantageously avoids liquefaction of the distal end of the connector at an early stage of the process.

[0327] Figure 60 The principle is shown that the entire connector can be pressed substantially into the first structure layer, the proximal end face of the connector 3 being almost flush with the proximal surface plane 9 of the first object.

[0328] Figure 61 An embodiment of the connector is shown which, in addition to having a flange 3.5, also has a step portion forming a shoulder of the tube portion 3.2 on the radially outer side. Once the connector has advanced into the first object 1 to a sufficient extent, in particular the end moving towards the front (towards the distal side), the step portion will come into physical contact with the first structure layer 1.1. As a result, due to the friction between the vibrating connector and the first structure layer 1.1, energy will be absorbed and the thermoplastic material of the connector will become flowable in the vicinity of the first structure layer. The flowable portion will thus include the portion in the proximal region and in particular the portion immediately distal of the first structure layer. This can act as, for example, a reference Figures 16a to 16c , Figure 23 , Figures 39 to 43 , Figures 47 to 50 , Figures 57 to 57b As an additional or alternative measure to the measures described, which also help to create a flowable portion and a radial flow immediately distal of the first structure layer 1.1, the step portion 3.61 can be formed as an outward step.

[0329] As an additional or alternative measure to the measures described, which also help to create a flowable portion and a radial flow immediately distal of the first structure layer 1.1, the step portion 3.61 can be formed as an outward step. Figure 62As shown, the connector 3 can comprise an outward taper 3.62.

[0330] Optionally, in addition to such outward features (step 3.61, taper 3.62), the connector can comprise internal features such as an internal groove 3.69 that facilitates distal collapse of the first structural layer. Figure 63 An example is shown. Other structures comprising the measures described above can optionally be combined therewith.

[0331] Figure 64 A top view (as seen from the proximal side) of the connector 3 is schematically shown, which illustrates the principle that the aforementioned outward features (step, taper 3.62) can be formed as radial protrusions (e.g. distributed around the outer circumference). As an alternative, such outward features can also be circumferential, i.e. continuously extending around the outer circumference.

[0332] Referring to Figures 61 to 64 Such outward features as discussed can involve the first structural layer 1.1 during the process of making the thermoplastic material flowable and can cause the connector to collapse.

[0333] Referring to Figure 65 Alternative design principles of the connector 3 with such outward features are discussed.

[0334] A possible first principle is that the height hi of the part that does not comprise outward features (i.e. the part of the outer surface that is cylindrical (which does not necessarily imply a shape of a rotational cylinder)) is larger than the piercing height h2. The piercing height h2 is always larger than or equal to the thickness of the first structural layer 1.1 and may, for example, correspond to the cumulative thickness of the first structural layer and a reinforcing density adhesive layer proximal thereto that also needs to be pierced.

[0335] In Figure 65 , reference 3.65 denotes a proximal liquefaction zone, in which the thermoplastic material becomes flowable due to friction with the first structural layer 1.1. When the connector collapses, the thermoplastic material will flow outward (arrow 3.66) from the proximal liquefaction zone 3.65 to form a proximal part of the flow portion.

[0336] A second possible principle is that the thickness ti of the tube portion 3.2 is larger than the thickness t2 of the thermoplastic material that is kept radially inward of the proximal liquefaction zone 3.65. This can ensure that the collapse occurs proximal to the proximal liquefaction zone 3.65.

[0337] Figure 67 Reference can be made back to the Figure 2 , 17The principle of 27 (i.e., flange 35 in the illustrated embodiment) is used to secure the second object 2 to the first object 1. Compared to embodiments with other features, the second object 2 has a portion 2.1 protruding away from the plane defined by the first structural layer 1.1 and facing proximally around the opening where the connector 3 is inserted. At the end of the approaching anchoring process, the distal surface of flange 35 presses against the edge 2.1 formed around the opening, while mechanical vibration maintains coupling to the connector. Therefore, after recuring, in addition to achieving further anchoring as described above, the connector is also secured to and anchored relative to the first object by the edge embedding into the thermoplastic material of the connector. Furthermore, a sealing effect is achieved if the edge is continuously embedded around the opening.

[0338] Figure 68 The resulting arrangement is partially shown.

[0339] Figure 69 This illustration shows another variant example (whose features may be similar to...) Figure 67 / Figure 68 (The concept shown is combined). That is, an adhesive 51, for example, in a flowable state, is applied between the first and second objects.

[0340] Therefore, the concept of adhesive bonding and securing a second object via a connector according to the invention is combined. For example, this could be useful if the second object is bonded to the first object by adhesive during manufacturing, but the components of the first and second objects are processed immediately after assembly. The connector used according to the invention provides sufficient initial stability for subsequent production steps.

[0341] During the final stage of the aforementioned anchoring process, the energy input and pressure can cause adhesive flow applied between the first and second objects (and / or between the distal surface of flange 3.5 and the second object), in certain embodiments. This can be used in the following manner:

[0342] - Gaps or cracks / fissures between the first structural layer 1.1 and connector 3 can be filled with adhesive, thus "restoring" the structure. This is as follows: Figure 70 As shown.

[0343] -Additionally or alternatively, the roughness 1.21 of the first structural layer 1.1 is interpenetrated by the adhesive 51, thereby enhancing the stability of the adhesive bond (see also...). Figure 70 ).

[0344] - As a supplement or alternative, the macroscopic or microscopic surface structure of the connector can be enhanced by interpenetrating adhesives to improve connection stability. This surface structure can exist on the side surfaces of the basic cylindrical portion ( Figure 71on the proximal lateral protruding feature (here: flange 3.5; reference 3.82).

[0345] Figure 72 The principle of a through hole 2.3 in the second object 2 is also schematically shown, which is not circular and thus non-symmetrical with respect to rotation around the proximal-distal axis. This can be Figure 67 Any of the configurations of / 68 or shown in other figures showing the second object 2, the second object has a substantially planar portion surrounding the opening 2.3.

[0346] With a through hole that is not circular, the connector is fixed in a form-fit manner against rotational movement relative to the second object (and thus in many embodiments also relative to the first object, e.g. if the second object is fixed to the first object in multiple locations).

Claims

1. A connector (3) for securing a second object (2) to a first object in the form of a lightweight structural element, and anchoring it into the lightweight structural element including a first outer structural layer (1.1) by means of mechanical vibration and at least one pressing force, said connector comprising: • Proximal contact surface for coupling the at least one pressing force into the connector (3); • The main body (31, 3.1) includes the contact surface; • A distal tube portion (3.2) extending distally from the body portion (31, 3.1) and providing a piercing and / or stamping structure (3.4), wherein the body portion laterally protrudes from the tube portion (3.2), thereby defining a flange (3.5); and • A solid thermoplastic material that can be liquefied by applying the mechanical vibration and at least one of the compressive forces; • The connector has a mating portion (3.28) on the distal side of the flange (3.5), wherein the mating portion (3.28) is sized to have a cross-section slightly larger than the opening of the second object (2); • Wherein, the cross-section of the insertion portion (3.28) is larger than the cross-section of the distal tube portion (3.2), wherein the tube portion (3.2) penetrates the lightweight structural element during the anchoring process; • Wherein, the plug portion (3.28) is configured to be pressed into the opening of the second object (2) near the end of the anchoring process, wherein mechanical vibration and pressing force cause a tight connection between the plug portion (3.28) and the second object (2); • The plug portion (3.28) includes a plurality of radially extending ribs, which, in addition to serving as a plug portion, also have energy guiding characteristics, such that the ribs absorb energy coupled into the connector (3) and thereby generate a flow portion when in contact with the first object (1).

2. The connector (3) according to claim 1, wherein, The tube (3.2) is hollow and / or sleeve-shaped.

3. The connector (3) according to claim 1, wherein, The tube (3.2) has a circular cross-section.

4. The connector (3) according to claim 1, wherein, The tube is made of the thermoplastic material.

5. The connector (3) according to claim 1, wherein, The main body portion closes the proximal end of the tube.

6. The connector (3) according to claim 1, wherein, The main body is plate-shaped.

7. The connector (3) according to claim 1, wherein, The main body is configured as the first outer structural layer (1.1) of the first object (1) that is displaced in the distal direction from the tube.

8. The connector (3) according to claim 1, wherein, The piercing and / or stamping structure formed by the distal tube (3.2) is configured to partially displace the first object (1) by piercing and / or stamping through the first outer structural layer (1.1) of the first object (1) under the action of the pressing force and / or the mechanical vibration.

9. The connector (3) according to claim 1, wherein, The piercing and / or stamping structure (3.4) is configured to provide a stamping profile with or without interruption.

10. The connector (3) according to claim 1, wherein, The stamping structure (3.4) is blunt.

11. The connector (3) according to claim 1, wherein, The connector includes a fastening hole (3.13).

12. The connector (3) according to claim 11, wherein, The fastening hole includes threads or other fastening structures.

13. The connector (3) according to claim 1, wherein, The fastening hole (3.13) is open in the contact surface.

14. The connector (3) according to claim 1, wherein, The piercing and / or stamping structure (3.4) is sharp.

15. The connector (3) according to claim 1, wherein, The stamping edge is formed by the outward tapered portion of the tube (3.2).

16. The connector (3) according to claim 1, wherein, The stamping edge is formed by the inward tapered portion of the tube (3.2).

17. The connector (3) according to claim 15 or 16, wherein, The stamping structure (3.4) is configured to provide a stamping profile with discontinuities.

Images