DE102005026505A1 - Method for connecting two components by means of friction welding and welded connection - Google Patents

Abstract

The invention relates to a drive element of a camshaft drive, in which a first component (11) and a second component (12) are connected to one another via a friction welding process. DOLLAR A According to the invention a "wedge-shaped", rotationally symmetrical intermediate element (22) is rotationally pressed into a gap (29) between the first component (11) and the second component (12), so that between a curved welding surface (27) of the connecting element (22). and the counter surface (18) of the first component (11) results in a friction weld. The manufactured friction-welded joint is operational and time-proof, eliminates micro-sanding between the components (11, 12) and has a lower weight and a small required installation space.

Description

Territory of invention

The The invention relates to a method for connecting a first component with a second component over an additional Connecting element using a friction welding. Farther the invention relates to a welded joint in which a first Component and a second component via an additional connecting element by means of a friction welding connected to each other.

background the invention

From the publication DE 695 10 770 T2 It is known to connect two tubes in the region of their conically widened ends by a connecting element with each other. The connecting element has two conical outer surfaces with opposite cone angles. These conical surfaces are welded to the inner surfaces of the cone-shaped ends of the tubes by means of a friction welding process. Reinforcement of the connection of the tubes is made by rings of wedge-shaped cross-section, which are respectively supported on the outer surface of the cone-shaped ends of the tubes and are externally surrounded by an outer reinforcing ring.

From the publication DE 94 05 814 U1 is the use of a friction welding method for connecting cams to a camshaft known. From the publication DE 44 37 396 A1 is a built camshaft of individual sub-segments known in which the sub-segments are joined together in radial joining planes by means of a friction welding process. The publication DE 40 29 026 A1 also relates to a friction welding method for different sub-segments of a camshaft or crankshaft. Fundamental considerations for carrying out a friction welding process of any workpieces are, for example, the document DE 33 07 445 C2 refer to.

Task of invention

• – der Herstellung der Reibschweißverbindung,
• – der Herstellung der Bauelemente und/oder
• – der Eigenschaften der hergestellten Verbindung

verbessert ist. Weiterhin liegt der Erfindung die Aufgabe zugrunde, eine Schweißverbindung vorzuschlagen, die die zuvor erwähnten Anforderungen erfüllt. Insbesondere beschäftigt sich die Erfindung mit einer Welle-Nabe-Verbindung, beispielsweise für ein Antriebselement eines Nockenwellentriebes.The invention has for its object to provide a novel method for connecting components via a friction welding, which in terms

• The manufacture of the friction-welded connection,
• - The production of components and / or
• - the properties of the compound produced

is improved. Furthermore, the invention has for its object to propose a welded joint, which meets the aforementioned requirements. In particular, the invention is concerned with a shaft-hub connection, for example for a drive element of a camshaft drive.

Summary the invention

According to the invention Task by a method according to the features of the independent claim 1 solved. Furthermore, the object is achieved by a welded joint according to Characteristics of the independent claim 5 solved. Further embodiments The invention will become apparent according to the features of the dependent claims 2 to 4 and 6 to 18.

For the inventive method the components are arranged such that between them Interspace is formed, for example, a radial gap or radial gap. The connecting element has a welding surface, which in the course of the friction welding process for abutment with a space bounding the gap of the first component comes and here via a friction welding welded to the first component becomes. A connection with the second component can also in the same operation by means of a friction welding process getting produced. Alternatively, it is possible for a connection made with the second component in a preceding or subsequent operation is, wherein this compound is also a Reibschweißverbindung can act or any other, known per se solid Connect.

The Invention is based on the knowledge that not an immediate Connection made between the first and second component must be, but this an additional connection element is used. By using the three elements (first Component, second component, connecting element) can this In the field of the compound to be produced, initially a variety of different Have geometries that are diverse options for the manufactured friction welded joint Offer. Furthermore, according to the invention, the use of the same or different materials for the elements possible. Furthermore, for the connecting element is a material corresponding to the first component and / or the second component are chosen or a completely different Material. Besides the possibility the choice of the same or different steels or alloys is so for example, a combination of a metal with a plastic, a ceramic or glass possible.

on the other hand allows the arrangement of an additional Verbindungselementes a duplication of possibilities for the thermal and mechanical properties of the elements used. This means, for example, that when choosing a material, which in the course of friction welding size Deformations may suffer the tolerances for the contact contours the elements used are chosen to be relatively large can.

Of the Use of a friction welding process has across from usual Welding process Advantage that a rotationally symmetrical heating and welding of the takes place with each other to be connected components. As a result, undesirable distortions and deformations, especially in thin-walled Components, and undesirable high, unequal distributed internal stresses are avoided, which over the Friction welding connected components by a high degree of functionality, quality and dimensional stability as well as dynamic time stability can distinguish. Furthermore, on the Use of screws, rivets, etc. for making connections be omitted, which space can be saved. hereby is a connection also allows for components, the very thin formed are and not by classical technology methods such as shrinking, Welding, Gluing, pressing, riveting, screwing, with positive or positive locking can be connected. A weld preparation according to other welding methods not necessary. Unlike alternative joining techniques do not pollute the environment or humans such as radiation, splashes, smoke, adhesive fumes, etc. on. There are not any Additives or a protective gas required. Furthermore results u. U. a cheaper microstructure the compound and the elements, in particular no melting or Cast structure. Insert can be done in seconds. There is a potentially higher level of automation before than in the production of a shrink connection. The friction-welded connection according to the invention can be produced with a low energy requirement. Farther can be a welded joint with high quality be produced, with only a small heat input into the weld metal, so that no melt arises. There is a symmetrical heating and Cooling, which leads to a particularly low-distortion connection with possibly symmetrical Residual stresses. The friction welding connection guaranteed so u. U. also a high accuracy of the connected components.

According to one Another proposal of the invention rests the first and second components during the friction welding, while the connecting element is set in rotation. An active compound of Connecting element with the first component is thereby brought about that the connecting element in a joining direction is moved, in the joining direction is acted upon by a contact force and at the same time a drive torque is applied to the connecting element, so that the necessary Friction for the friction welding between caused the connecting element and the first component. Especially for relatively large components and / or unbalanced components with an imbalance can it from Be beneficial if the components are not rotated have to. Here is the movement of a small connector with a low Moment of inertia advantageous. Furthermore possible This embodiment of the invention that the components as a dormant Parts are arranged in a fixed position to each other, so that after production of the friction-welded joint, the components a have exactly predefined orientation to each other and location.

One preferred connection method can be designed in such a way that the first component and the second component first with a cover in joining direction arranged to each other, wherein between the first component and the second component transverse to the joining direction a (circulating) Interspace is formed. Following this, the first and second components across from the environment, for example by suitable brackets, and / or fixed against each other. In the next step the connecting element is rotating and under application of a Drive torque and a contact force in the aforementioned gap introduced. this leads to to a frictional contact between the welding surface of the connecting element and a suitable mating surface of the first component, so that a Reibschweißverbindung is produced. With sufficient warming and connection of the connecting element and the first component is the rotation of the connecting element is terminated and there is a Cooling of the elements.

In the case, that as a result of the previous production of the elements and / or as a result the preparation of the compound still disturbing areas of the elements can exist this by a machining rework, for example, a turning eliminated become. In the course of the machining, the elements can alternatively or additionally brought to a precise level become.

In the event that the components are formed on the one hand as a shaft and on the other hand as a hub, it is advantageous if the intermediate space is formed as a (circumferential) radial gap between the shaft and the hub. This gap can be in axial Direction be formed continuously. Alternatively, it is also possible that the gap and gap exists only over a portion of the axial length of the hub, while in the area of another portion of a game or a transition fit between the shaft and hub is given, so that already a pre-positioning between the shaft and hub possible is.

Preferably is the connecting element with both the first component as also with the second component over a friction welding process is connected, in particular in a single friction welding connection step. in this connection is the connecting element radially inward with the second component connected while a connection with the first component in the area of the welding surface lying outside from the connecting element.

Corresponding a development of the invention is at least a subarea the contour of the welding surface of the Connecting element opposite the joining direction by an angle α with 0 <α <90 ° inclined. If the connecting element in such a sub-area to Attachment to the first component, the contact pressure in accordance with the Angle α divided in a component which is oriented in the direction of the contour and a component across the contour. Similar to a wedge effect can over the Design of the welding surface with a contour at an angle α with small contact forces one size Contact force generated in the welding surface, the for the production of the welded joint responsible for. At the same time the contact force component leads in certain circumstances for the fastener to stress transversely to the contour of the weld surface and is deformed, resulting in deformation of the connecting element to lead can that be dependent from the contact force. Such deformation can be used become an increase the contact pressure of the connecting element on one of the contour of the Weld surface opposite Side to the second component.

Furthermore, the contour of the welding surface can not only have an angle α but at least two partial regions with different angles α ₁ and α ₂ . By specifying the angles α ₁ and α ₂ , a different heating and / or a different plastic and / or elastic deformation can be structurally predetermined in different subregions of the welding surface. The abovementioned angles α, α ₁ and α ₂ can be given only in discrete sections over the contour of the welding surface or over an area of the contour. Here, the design of this contour with the angles α, α ₁ and α _{2 may be given} only over a partial circumference or over the entire circumference. This may then result, for example, a contour of the welding surface, which is formed in a plurality of conical, in particular double conical, wherein the cone angle gradually increases or decreases in the direction of the longitudinal extent of the connecting element. The choice of a cone-shaped welding surface has u. U. the additional advantage that with an entry of the connecting element in the component in consequence of the conical surface can be done self-centering.

Corresponding an alternative embodiment, the contour of the welding surface is curved, so that the slope of the contour does not vary step-by-step is, but continuously, possibly with individual jumps.

When it has turned out to be particularly advantageous if the Contour of the welding surface one Part of a spiral corresponds.

For example This may be a so-called "golden spiral" or "logarithmic spiral". The design Such a golden spiral is here the expert or Mathematician known. For example, such results Contour design from relevant Pages of the Internet on the term "golden spiral", for example www.mathe.tu-freiburg.de as well as using simple drawing means and fibbonacci numbers or based on the so - called "Golden Triangle Method", s. a. the designs on Fibonacci squares and spirals at www.netlinx.de/fibonacci.

According to one first embodiment of a development corresponds to the contour an associated counter surface a component of the contour of the welding surface (at least in partial areas). The corresponding contours thus occur during friction welding same time to each other to the plant, so for this Contour areas simultaneously a welded joint is made.

For an alternative Design are the contours of the counter surface of a component and the Welding surface deviating formed to each other. This can be specified by the deviations targeted be that contours during the friction welding process not at the same time to each other to the plant, but temporally added. This can be a "layer by layer Structure of the friction-welded connection produced for earlier produced earlier Contact areas a greater deformation while the friction welding process is manufactured as for later in time contacting contour areas.

Preferably, a drive element is formed in a camshaft drive with the first and second component. For example, it is in the drive element to a sprocket spur gear for a camshaft adjuster, an inner or outer rotor of a camshaft adjuster, a connection of a camshaft with a gear, an adjusting element or the like. Known such compounds are formed in particular by means of a shrink connection. For thin-walled constructions, such a shrink-fit connection may result in micro-walking during dynamic load operation, which is undesirable and may result in degradation or failure of the function of a camshaft drive. Furthermore, such a shrink connection is dependent on a surface procurement of the contact surfaces of the shrink fit and the manufacturing processes such as a turning process, grinding, honing or blasting. An elimination of a micro-sanding by increasing the coverage in a transverse compression bandage can be limited, since the components involved may have insufficient mechanical strength for this purpose. Welding of any kind causes impermissible distortions in the toothing area, which may be material-dependent. Also gluing is u. U. not possible because the compound produced for use in motor vehicles must be designed for at least 15 years without problems and fail-safe. For the arrangement of screws, rivets or a positive or frictional connection is not enough space available in the said drive elements. The aforementioned problems are avoided by the use of the friction welding method according to the invention for a drive element of a camshaft drive.

• – sehr niedrige Wärmeeinflusszonen in den Bauteilen, da eine rasche Abkühlung der hauchdünnen Thermoplastizitätsschichten schon während des Reibschweißprozesses entsteht,
• – keine Änderung der kristallinen und/oder chemischen Struktur der Werkstoffe der Elemente,
• – keine oder verminderte Neubildung von neuen Kristallstrukturen, die nachteilig sein könnte, beispielsweise Chrom- oder Kohlenstoffkristallzonen, bzw. Faserstrukturen,
• – kein Austritt von Schmelzflüssigkeit aus einer Schweißfuge,
• – gezielte Bildung der Schweißnahtstruktur im plastischen Zustand, beispielsweise "rührmäßig",
• – Herstellung einer geometrisch stabilen Verbindung, da beim Abkühlen kein Schrumpfen erfolgt.

According to a particular proposal of the invention, the first component, the second component and / or the connecting element are merely plasticized during the friction welding, but not melted, so that the temperatures reached are below the melting temperature of the selected materials. A plasticizing compound is a stable fusion process that does not melt the material. The material is merely put in a thermo-plastic state and produced layer by layer in the intermediate space. Dough-like mixing of the plastic layers creates a bond characterized by deep diffusion and alloying of the materials. This creates a highly stable welded joint of the components. Due to a lack of melting during friction welding, the following advantages can be achieved:

• Very low heat-affected zones in the components, since a rapid cooling of the wafer-thin thermoplasticity layers already occurs during the friction welding process,
• - no change in the crystalline and / or chemical structure of the materials of the elements,
• No or reduced formation of new crystal structures, which could be disadvantageous, for example chromium or carbon-crystal zones, or fiber structures,
• No leakage of molten liquid from a welding joint,
• Targeted formation of the weld seam structure in the plastic state, for example, "stirring",
• - Preparation of a geometrically stable compound, since no shrinkage occurs during cooling.

at classic friction welding process are the very high mechanical material and component loads due to the compression force and the friction torque disadvantageous. This is avoided by minimizing the crush force over a suitable contour of the weld area, because the contact pressure in the majority only axially loaded the first component to pressure. In the radial direction is the "golden spiral profile" with a small one Slope of the contour equipped, resulting in many smaller radial deformations caused the first component. The contours of the invention the components and the connecting element, in particular the welding surface, are easily produced by sintering, stamping or turning.

advantageous Further developments will become apparent from the dependent claims, the description and the Drawings. Other features are the drawing, especially the illustrated geometries of the components, the relative dimensions several illustrated dimensions same or different components, the relative arrangement the components to each other and their operative connections with each other, refer to. The combination of features different in various figures illustrated embodiments or features different claims is also possible and is hereby stimulated.

Short description the drawings

Two embodiments The invention are shown schematically in the drawing. Show it:

1 a first embodiment of a welded joint according to the invention in half longitudinal section;

2 a contour of a welding surface of a connecting element, which is suitable for use in a welded joint according to 1 suitable is; and

3 an alternative embodiment of a Welded joint according to the present invention.

Full Description of the invention

In 1 is a welded joint 10 with a connection of a first component 11 with a second component 12 represented by a friction welding. For the illustrated embodiment, it is in the first component 11 around a hub 13 while the second component 12 a (hollow) shaft 14 is. The wave 14 is hollow cylindrical with an outer surface 15 and has a radial oil hole 16 ,

The hub 13 has radially inward over a partial area with a cylindrical inner surface 17 and a partial area with a counter surface 18 , whose contour 19 in the semi-longitudinal section according to 1 is apparent and rotationally symmetric to a longitudinal axis 20 the welded joint 10 is trained. The hub 13 has a radial oil hole 21 , which correspond to the oil well 16 is trained.

A connecting element 22 is in the 1 Halflängsschnitt shown simplified as wedge-shaped and rotationally symmetrical to the longitudinal axis 20 educated. The connecting element 22 has a cylindrical inner surface 23 and a radially outer outer surface 24 in the in 1 from the hub 13 cantilevered area is approximately cylindrical and in which in the hub 13 arranged portion of a contour 25 forms. In the contour 25 opposite end portion has the connecting element 22 a functional area 26 , which is suitable for cooperation with a tool, a holding and / or pressing and driving device is formed.

2 shows different embodiments of the contour 25 of the connecting element 22 , A first contour 25a is formed according to a circular arc, an ellipse, an inclined half-load of a parabola, a curve or a spiral. The alternative contours 25b - 25e are with a straight line section with an angle α or more straight line sections of different angles α ₁ , α ₂ with respect to the longitudinal axis 20 educated. For the contour 25b is the angle α over the entire length of the contour 25b constant, so that the radial extent of the connecting element 22 starting from a tip, which may also be formed blunt or rounded, continuously up to the cylindrical portion of the outer surface 24 increases. The contour 25c first has a larger pitch α ₁ and then goes over a bend or rounded kink over in another sub-area with a slope α ₂ . The contour 25d consists of three subregions with gradients α ₁ > α ₂ > α ₃ . The contour 25e owns according to the contour 25c two sections with gradients α ₁ and α ₂ , where for the contour 25e the slope α _{1 is} smaller than for the contour 25c and the slope α ₂ for the contour 25e is smaller than the slope α ₂ for the contour 25c ,

The contour 25 forms one around the longitudinal axis 20 circumferential welding surface 27 , in the area of which the connecting element 22 via a friction welding process with the counter surface 18 the hub 13 is connected.

To connect the hub 13 with the wave 14 be first hub 13 and wave 14 arranged relative to each other according to the intended end position, wherein hub 13 and wave 14 by holding devices 28 can be supported against the environment. In addition, hub can 13 and wave 14 be fixed in a manner not shown directly against each other, for example by a locking pin, which passes through a bore corresponding to the oil holes 16 . 21 passes. In this position form the inner surface 17 the hub 13 and the lateral surface 15 the wave 14 a transitional fit. Between the welding surface 27 and the lateral surface 15 is one around the longitudinal axis 20 circumferential gap 29 educated ( 1 with the connector removed 22 ). Following this is the connecting element 22 in joining direction 30 that are coaxial with the longitudinal axis 20 is, in the gap 29 introduced. This is the connecting element 22 set in constant, variable or intermittent rotation, especially at high speed. The connecting element 22 comes in the area of a joining direction 30 front face in frictional contact with the mating surface 18 the hub 13 , preferably in the area of the contour 25 with the angle α ₁ . This leads to a plasticization in the front region of the connecting element 22 and / or the associated area of the mating surface 18 , thus providing a further feed in the joining direction 30 of the connecting element 22 is possible. Gradually, further areas of the contour come 25 for abutment with assigned areas of the mating surface 18 , so that several thermally plasticized layers in the connecting area between hub 13 and connecting element 22 result. These plastically deformed layers provide mechanical mixing, diffusion and alloying with the interface layers of interconnecting element 22 and hub 13 which may possibly solidify rapidly during cooling. Depending on the drive and feed conditions, plasticization may be present in the area of the entire subsequent welding surface, or solidification of front portions may occur, while rear portions are still plasticized or are.

This is followed by the drive and the feed of the connecting element 22 disabled and the components can continue to cool. In a subsequent machining process can disturbing material areas, such as a formed bead 31 and / or supernumerary unnecessary parts 32 up to a borderline 33 be machined or turned off.

Out 3 it can be seen that in addition to the functions of the hub 13a For example, as a sprocket with teeth 34 , and the function of the shaft 14a , for example as a spur gear 35 , also the connecting element 22a not only can serve the connection, but also other functions, such as an additional spur gear 36 or sprocket, can meet.

A weld between the connecting element 22 and the wave 14 By friction welding can be achieved only by the fact that for the diameter design of the lateral surface 15 and the inner surface 23 a transition or interference fit is chosen. Alternatively or additionally, the pressing in of the connecting element 22 in the opposite surface 18 the hub 13 to that the connecting element 22 is deformed radially inwardly, so that a contact force between the connecting element 22 and wave 14 is produced or enlarged, which leads to a friction welding process.

Unlike the illustrated embodiments, it is also possible that in a reversal of the welding surface 27 with the contour 25 not on the outer surface of the connecting element 22 is provided, but radially inwardly with appropriate design of the outer surface of the shaft 14 , It is also possible that in addition to a contour 25 also the other radially limiting surface of the connecting element 22 not cylindrical, but with any contour or bevelled is formed with a suitable mating surface of the hub 13 or wave 14 ,

10

welded joint

11

first module

12

second module

13

hub

14

wave

15

lateral surface

16

oil well

17

palm

18

counter surface

19

contour

20

longitudinal axis

21

oil well

22

connecting element

23

palm

24

outer surface

25

contour

26

functional area

27

welding surface

28

holder

29

gap

30

joining direction

31

bead

32

unnecessary subarea

33

boundary line

34

tooth

35

spur gear

36

spur gear

Claims (18)

Method for connecting a first component ( 11 ) with a second component ( 12 ) via an additional connecting element ( 22 ) using a friction welding, characterized in that the additional connecting element ( 22 ) into a space ( 29 ) between the first component ( 11 ) and the second component ( 12 ) and in the region of at least one welding surface ( 27 ) of the connecting element ( 22 ) via a friction welding with the first component ( 11 ) is welded. Method according to claim 1, characterized in that the components ( 11 . 12 ) during friction welding and the connecting element ( 22 ) rotating, under motion and under load in a joining direction ( 30 ) and applying a drive torque to the first component ( 11 ) is brought into operative connection. Method according to claim 1 or 2, characterized in that - the first component ( 11 ) and the second component ( 12 ) with an overlap in the joining direction ( 30 ) and with a gap ( 29 ) transverse to the joining direction ( 30 ) are arranged to one another, - the first component ( 11 ) and second component ( 12 ) are fixed relative to the environment and / or against each other, - the connecting element ( 22 ) in the joining direction ( 30 ) rotating, applying a drive torque about the joining direction ( 30 ) and applying a contact force into the gap ( 29 ), whereby a frictional contact between the welding surface ( 27 ) of the connecting element ( 22 ) and a counterface ( 18 ) of the first component ( 11 ), - the rotation of the connecting element ( 22 ) is terminated and - a cooling is allowed. A method according to claim 3, characterized in that after cooling, a machining post-processing of the first component ( 11 ), of second component ( 12 ) and / or the connecting element ( 22 ) he follows. Welded connection with a first component ( 11 ) and a second component ( 12 ), which has an additional connecting element ( 22 ) and friction welding are interconnected, characterized in that the connecting element ( 22 ) in a space ( 29 ) between the first component ( 11 ) and the second component ( 12 ) is arranged and that the connecting element ( 22 ) in the region of at least one welding surface ( 27 ) of the connecting element ( 22 ) with the first component ( 11 ) is welded. Method according to one of claims 1 to 4 or welded connection according to claim 5, characterized in that the components ( 11 . 12 ) as a wave ( 14 ) and hub ( 13 ) are formed and the space ( 27 ) as a radial gap between shaft ( 14 ) and hub ( 13 ) is trained. Method or welded joint according to one of claims 1 to 6, characterized in that the connecting element ( 22 ) radially inwardly via a friction welding with the second component ( 12 ) is connected and radially outboard with the first component ( 11 ) in the area of the welding surface ( 27 ) is connected via friction welding. Method or welded joint according to one of claims 1 to 7, characterized in that at least a portion of the contour ( 25 ) of the welding surface ( 27 ) of the connecting element ( 22 ) opposite the joining direction ( 30 ) is inclined by an angle α with 0 <α <90 °. Method or welded connection according to claim 8, characterized in that the welding surface ( 27 ) rotationally symmetrical to the joining direction ( 30 ) and has a wedge-like contour. Method or welded joint according to claim 8 or 9, characterized in that the contour ( 25a ; 25c ; 25d ; 25e ) of the welding surface ( 27 ) has at least two partial regions of different angles α ₁ and α ₂ . Method or welded joint according to claim 10, characterized in that the contour ( 25a ; 25c ; 25d ; 25e ) of the welding surface ( 27 ) is formed multi-cone-shaped. Method or welded joint according to claim 11, characterized in that the contour ( 25a ) of the welding surface ( 27 ) is curved. Method or welded joint according to claim 12, characterized in that the contour ( 25a ) of the welding surface ( 27 ) is at least approximated to a portion of a spiral. Method or welded joint according to one of claims 1 to 13, characterized in that the contour ( 19 ) of the counter surface ( 18 ) of the first or second component ( 11 . 12 ) prior to the production of the friction weld joint of the contour ( 25 ) of the welding surface ( 27 ) corresponds at least in some areas. Method or welded joint according to one of claims 1 to 13, characterized in that prior to the production of the friction-welded joint, the contour ( 19 ) of the counter surface ( 18 ) of the first or second component ( 11 . 12 ) from the contour ( 25 ) of the welding surface ( 27 ) deviates at least in some areas. Method or welded joint according to one of claims 1 to 15, characterized in that the first and second components ( 11 . 12 ) with interposition of the connecting element ( 22 ) form a shaft-hub connection. Method or welded connection according to one of claims 1 to 16, characterized in that with the first and second component ( 11 . 12 ) A drive element is formed in a camshaft drive. Method or welded joint according to one of claims 1 to 17, characterized in that during the friction welding only a plasticization - of the first component ( 11 ), - of the second component ( 12 ) and / or - of the connecting element ( 22 ) without melting.