Twist-beam axle for a motor vehicle

The invention relates to a torsion beam axle for motor vehicles.

In the automotive industry is to increase productivity a general desire for an economical as possible and the efficient production of automotive components. These requirements are also subject to torsion beam axles, which combines the advantages of a simple structure with low density and good kinematic properties unite. includes such a torsion beam axle essentially two trailing arms, which by a Cross members are connected, which acts as a torsion bar. To connect the trailing arm to the crossmember are different joining methods known in which a welding Determination is the most common.

usually be the twist beam axles of steel semi-finished products manufactured. In the course of a targeted lightweight construction but has also been as an aluminum over steel specifically lighter alternative proven.

From DE 44 16 725 A1, for example, is a torsion beam axle forth, one-piece which two by Cross brace connected steel trailing arms aluminum comprises or an aluminum alloy, wherein the longitudinal arm are produced by hot forming. The ends the cross strut are in a recess adapted to the inserted trailing arm and then welded. disadvantageous in this embodiment, the manufacturing costs and the associated additional costs. In addition, the weld naturally a geometrical and metallurgical notch represents the unfavorable effect on the may impact strength behavior.

DE 196 04 286 C1, it also counts on the state of Art, the trailing arms and the ends of the cross strut shrinking technically to connect. This technology is promising. However, from the thermal load in the manufacture joining adverse residual stresses result.

From DE 195 42 523 A1 it is known the ends of the Transverse strut of a twist beam rear axle with trailing arms to be joined by gluing. For this purpose, the transverse strut in each case at their ends with a pipe part made of Steel material welded, which in the respective Trailing arm is glued. For this, the tubular member is in the Bonding area provided a hollow cylindrical design. The diameter and the wall thickness of the pipe part in the Area of ​​the weld is by uniform deformation to the diameter and the wall thickness of the cross strut adjusted in this area. Also this production method is through the welding connection of the tubular parts at the ends of the cross strut manufacturing technically complex. Also in this case there is the problem that the Welded joint with regard to their strength behavior represents a potential vulnerability.

The invention is therefore, starting from the prior art the object of a torsion beam axle for motor vehicles manufacturing technology to further develop, in particular, Residual stresses in the region of the transitions from Cross member can be reduced to the trailing arms.

The solution of this problem consists in the in claim 1 listed features.

Advantageous refinements and developments of the invention Basic idea form the dependent Claims.

Core of the invention provides the measure that the longitudinal control arms adhesively directly to the crossbar to connect, including a between the ends and the recordings klebstoffbefüllbarer annular gap is formed. This enables an efficient production at a high quality combination of trailing arm and crossmember, which the required high safety standards fulfilled. The connection is dynamic highly resilient. The in operation taken by the trailing arms and torsion Bending forces are reliably in the crossmember transferred and compensated by this.

Thus in particular the use of adhesives, higher Viscosity of the adhesive for joining not the connection is displaced from the joint zone, it is provided that between the ends and the recordings a klebstoffbefüllbarer annular gap is formed. In the is annular gap before or after the joining of the components Adhesive introduced. Subsequent filling can have one or more apertures or bores in the components occur which enable an external terminal.

The annular gap can be achieved by suitable shaping of the Recordings or the ends carried. This can, for example, by a casting, a metal-cutting or a metal forming process carried out.

promises from a technological and economic point of view gluing the ends of the cross member in recordings Trailing arm many advantages. One of the most remarkable Advantages is the relatively favorable internal stress state the welded joints. While in the connection zone previous torsion beam axles with welded or compounds produced by pure press fit also without external loads High voltages, especially Include internal stresses occurred, according to the invention comprises glued connection of cross members and longitudinal links low joining residual stresses.

The recordings can be used as nozzle-like approaches, bulges or pins may be formed on the trailing arm, in or to which the ends of the crossbar are inserted. at tubular, shaped by hydraulic internal high pressure Trailing arms, the pictures are preferably hydroforming technically formed on the trailing arms. Of course, the shots on trailing arm be drafted and internally.

The geometry of the ends and the receiving determine the Power flow between the adherends. With regard to their Cross-section, the ends of the cross member and the Shoot a the force / form-fit between the components have increasing design. It is conceivable both a rotationally symmetrical design of the ends and the A RECORDING and a respectively against the same butt-jointed Cross-sectional configuration with elevations flattened or recesses. In this way, the highest Capacities are realized.

Besides exclusively bonded joint of crossmember and trailing arms has an advantageous embodiment, a twist beam axle according to the invention Claim 2 is a glued combined / compressed trailing arm crossmember connection on. Here, the ends the crossbeam also with a press fit into the receptacles the trailing arms together.

In one embodiment, the combined glued / pressed Compound is at room temperature of Outside diameter of the ends of the cross member slightly larger than the inner diameter of the shots. to join allow the recordings to be heated. After cooling then enters a compound or klebgeschrumpfte Querpressklebverbindung on. Alternatively, the excess may be between the adherends by pressing the ends in the Images can be overcome. It then creates a Längspressklebverbindung.

An alternative is by the features in claim 3 characterized. The connection of the ends in the receptacles is dimensioned as a clearance. The adhesive is applied to one or both joining faces and Components fitted together. Then the game the now filled with adhesive by a fit Shaping minimized. Ideally, the deformation process the occurrence of a compressive stress in the joint zone result. This can be achieved by that the shape of the components to be joined, or their material so are selected such that the elastic deformation of the recording is greater than the captured ends of a cross member. Upon initiation of the forming deform the recordings then plastically, while the ends of the Crossmember only elastically deformed. After completion the forming spring back ends. It is a compressive stress in the joint zone back which is an accelerating effect on the setting process of the adhesive affects and improves the strength of the connection.

Another significant advantage of the present invention Torsion beam axle is that from different Materials existing trailing arm and crossmember wärmearm or even can add heat free. In practice, especially a torsion beam axle is advantageous, according to To claim 4 is viewed, the crossmember is made of steel, whereas the trailing arm made of light metal, preferably made of aluminum or an aluminum alloy or magnesium or a magnesium alloy are manufactured.

This allows mixed construction of a torsion beam axle a high level of weight reduction while ensuring a very good elastokinetischen behavior of the torsion beam axle.

As the adhesive are preferred among others Epoxy used. The adhesive can be prepared by either a chemical reaction in two-component adhesives or by a physical process, such as evaporation the solvent, to set.

The bond to the joining surfaces between longitudinal control arms and the ends of the cross member is based primarily on the adhesion between the adhesive and metal, and the cohesive forces within the adhesive.

According to the features of claim 5 is an anaerobic curing adhesive is used. Reliable tying and thus bonding takes place in this adhesive even without the evaporation of a solvent. The adhesive guarantees a good wettability of the uniform Adherends, and low internal stress after setting. The tendency to shrink during setting is low.

One also is in practice highly suitable adhesive according to the features of claim 6 is a reaction adhesive. A Polyadditionsklebstoff cures example without release of fission products by an addition reaction out. The adhesive is no pressure hot and cold curable and has over the anaerobic adhesive systems a higher viscosity. The use of a therefore such an adhesive is particularly suitable for the production-related component tolerances of trailing arms and crossbeam on.

is also possible the use of physically curing Adhesives (claim 7), such as hot melt adhesives.

A further increase of elastokinetischen behavior a torsion beam axle is according to the features of claim 8 achieved by a cross member, which in its Central portion has a substantially V- or U-shaped cross-section. This cross-section is to the ends continuously towards circular or oval on a tubular cross section throughout.

The inventively provided adhesive technical connection the trailing arm to the crossmember is dynamic highly resilient. The load-capable connection of Cross profile enables transfer of torsional and Bending forces of trailing arms in the crossmember. The crossbeam compensated as torsion which introduced Forces. The twist beam axle according to the invention has been designed in efficient manufacture and has a good static and dynamic load behavior. Further is a weight-optimized design possible. To this end, transmits the saving of welds, screws or Rivets at. Further, by the adhesive bond very good trailing arms and transverse support of different types of metal combining materials. Especially good suitable is the combination of longitudinal beams of light metal on aluminum and / or magnesium base with cross-beams from steel.

The invention is described below based on the drawings described exemplary embodiments illustrated. Show it:<dl tsize="18"><dt>figure 1</dt><dd>in technically generalized representation a torsion beam axle according to the invention;</dd><dt>figure 2</dt><dd>the detail II of figure 1 in a horizontal section;</dd><dt>figure 3</dt><dd>a side view of the illustration of Figure 2 according to the arrow III;</dd><dt>figure 4</dt><dd>in cross section a detail of the end a cross member and a section of a longitudinal control arm prior to joining of the components;</dd><dt>figure 5</dt><dd>the view according to Figure 4 after joining the components; </dd><dt>figure 6</dt><dd>also in cross section each having a portion from the end of a crossbeam and a longitudinal member before joining process;</dd><dt>figure 7</dt><dd>the representation according to Figure 6 after the joining operation;</dd><dt>figure 8</dt><dd>in cross-section in each case a section of Crossbeam and longitudinal support a further Embodiment, prior to joining of the components;</dd><dt>figure 9</dt><dd>the view according to Figure 8 after the joining operation;</dd><dt>figure 10</dt><dd>a horizontal section through the representation the figure 9 along line X_-X with the clarification a forming operation and</dd><dt>Figures 11 to 13</dt><dd>in cross section shown schematically three further embodiments.</dd></dl>

The illustrations in the figures 1 to 13 are technically simplified and not to scale. In all Representations bear the corresponding components same reference numerals.

In the figure, 1 is a torsion beam axle 1 for front-wheel drive Motor vehicles shown schematically. The torsion beam axle 1 comprises two longitudinal control arms 2, 3 made of cast aluminum, connected by a one-piece crossmember 4 are. The crossbeam 4 acts as a torsion section and is made of strength and stiffness reasons high-strength steel. Most the transverse support 4 in its the central region, a substantially V- or U-shaped Profile which ends in a nearly circular or oval cross-section passes.

In the longitudinal control arms 2, 3 are device accessible sockets 5 and wheel bearings 6, shock absorber 7 and optionally Spring seats 8 integrated.

In the figures 2 and 3 is the detail II of Figure 1 shown in the horizontal section and in side view.

Each trailing arm 2 has a receptacle 9, which is a receiving end 10 of the cross member. 4 The recordings are 9 in their cross-sectional configuration to the ends 10 the crossmember 4 matched. The addition of trailing arms 2 and cross member 4 is made by an adhesive bond eleventh For this purpose, the adhesive or bonding surface with K adhesive wets and the end 10 into the receptacle 9 been fitted. Here comes an adhesive K high Strength and aging resistance with the application point relevant temperature range of reliable heat resistance for use.

is through the adhesion between adhesive K and metal a combined force / form-fitting with high binding and Sustainability between trailing arm 2 or 3 and crossbeam 4 achieved. The twist beam axle according to the invention 1 characterized by the weld-free transition from Crossbeam 4 on the trailing arms 2, 3 in. stresses in the transition region are minimized, can advantageously and longitudinal control arm 2, 3 and cross members 4 of different Materials are joined wärmearm.

Figures 4 and 5 show a section of a Torsion beam 1 with an adhesive compound 11 between the end 10 of a crossbeam 4 and the trailing arm . 2

The receptacle 9 is on the stub-shaped extension 12 Trailing arm 2 formed. The extension 12 has at its free end 13 a circumferential, inwardly directed Gorget 14. In approach 12 holes 15 are provided for the introduction of adhesive K.

After the end 10 is inserted into the receptacle 9, is in the intermediate annulus 16 through the Holes 15 adhesive K introduced. The width of Annular gap 16 is in this case by the width X of the annular collar 14 determined. Preferably, a solvent-free comes reactive adhesive K used. A Heat can be used to bind accelerating will. Further, thereby, the strength improves will. After the setting of the adhesive K is a reliable Adhesive bond 11 of trailing arm 2 and crossmembers 4 produced.

Figures 6 and 7 show an embodiment of a Torsion beam axle, in which the end 10 of the cross member 4 used with plastic deformation of the receptacle 9 in this is. The outer diameter D₁₀ is the crossmember 4 in the end region 17 corresponding to the inner diameter D₉ recording 9 matched, so that he in the receptacle 9 is inserted to form an annular gap 16 can be. The geometric dimensions are selected such that the end 10 of the cross member 4 when inserted in the receptacle 9, the wall 18 at the free end 19 plastically deformed outward and closes.

Over the holes 15 is formed between the end 10 and recording filled 9 formed annular gap with adhesive K.

After curing occurs a reliable connection of Crossbeam 4 and longitudinal members 2, a high rigidity the adhesive joint 11th

Basically, the above-described embodiment also suitable for the adhesive to the joining surfaces K apply and the end 10 with a press fit into the receptacle 9 use with plastic deformation of the free end 19th Holes in the wall of the receptacle are then not mandatory.

In the figures 8 to 10 an alternative is shown, in which the end 10 of the cross member 4 with a clearance P is dimensioned. Accordingly, the outer diameter D₁₀slightly smaller than the inner diameter D₉ recording 9. K adhesive is on one or both joining surfaces applied, after which the end 10 is inserted into the receptacle 9 becomes. Then the game is now with K adhesive filled fit P by a forming minimized.

The forming process is illustrated with reference to FIG 10th adapted to the outer contour of the receptacle 9 and the end 10 Press halves 20 acting on the connecting portion 21 on. The press pressure is indicated by the arrows U. Here is the play between the end 10 and receiving 9 minimized. This is done by plastic deformation the receptacle 9, whereas the end 10 resiliently is deformed and back cushions for relief. hereby can be built a compressive stress, the advantageous the joining zone or the adhesive joint 11 of Components 9, 10 effect. It comes as combined into a glued / pressed adhesive joint 11th

In the preparation of technical joining compound 11 can the cooperation of a different plastic and elastic deformation capacity of recording 9 be exploited or end 10th In this context it is advantageous if the longitudinal control arm 2, or the recording 9 and the cross member 4 and the ends 10 of materials consist of mutually different resilience properties, as in the combination of Longitudinal control arms 2, 3 of aluminum or magnesium based and Crossbars 4 is the case based on steel.

The force is then the component 9 or 10 with the lower elastic deformation capacity. Due to the stronger spring-back of the other component remains after joining back an interference fit.

With the material combination aluminum / steel, for example, has steel on the lower elasticity. The order is then designed so that there is a picture 9 plastically deformed under the influence of an external force, while the end 10 is elastically deformed. at the material combination aluminum / steel, therefore, the external force introduced via the component of steel. by virtue of the stronger spring-back of the aluminum component remains after joining back an interference fit. These affects both an accelerating effect on the setting process as well as strength-increasing effect on the connection 11th

The force at a shaping process can also take place inside of the end 10 of a crossbeam 4, as This is shown schematically in the figure eleventh Here is the end 10 from the inside by a tool 22 under Force distribution F in the receptacle 9 of a trailing arm 2 expanded aluminum. Here there is a deformation in wet with adhesive K connecting region and it turns a combined glued / pressed adhesive bond 11 a.

A further alternative is shown in the figure 12, at the pin-shaped end 10 of a crossbeam 4 a Up 9 a trailing arm 2 with introduction is plugged by adhesive K. In addition, the end of 10 under external force plastically and recording 9 are elastically deformed. Again, it comes at a Material combination aluminum / steel to a press fit after joining.

Finally, in the Figure 13, an embodiment is shown, in turn, a filled with adhesive K Annular gap 16 formed between seat 9 and the end 10 is. To this end, the receptacle 9 and the end 10 are graded. The end 10 passes via a shoulder 23 in a in Reduced diameter pin 24 over. The recording 9 has an upper portion 25 and a lower portion 26, the lower portion 26 via a Stage 27 relative to the diameter of the upper portion 25 is reduced. The pin 24 fits geometrically matched and sealed in the lower portion of a 26th The end 10 with its longitudinal section l₁ at the top Section 25 performed. Between the top portion 25 and the pin 24 is formed as the adhesive-filled Annular gap 16 from. By applying a joining force P_F in axial direction of the cross member 4 is built up in the joint zone the adhesive K a compressive stress on. Preferably the joining force P_F during curing of the adhesive maintained K.

<b>REFERENCE NUMBERS</b>

<dl tsize="4" compact="compact"><dt>1</dt><dd>- Beam axle</dd><dt>2</dt><dd>- Trailing arm</dd><dt>3</dt><dd>- Trailing arm</dd><dt>4</dt><dd>- Crossbeam</dd><dt>5</dt><dd>- jack</dd><dt>6</dt><dd>- Wheel</dd><dt>7</dt><dd>- Shock absorber</dd><dt>8th</dt><dd>- Spring seat</dd><dt>9</dt><dd>- Admission</dd><dt>10</dt><dd>- End v. 4</dd><dt>11</dt><dd>- Adhesive bond</dd><dt>12</dt><dd>- approach</dd><dt>13</dt><dd>- Free end v 12th</dd><dt>14</dt><dd>- Gorget</dd><dt>15</dt><dd>- drilling</dd><dt>16</dt><dd>- Annular gap</dd><dt>17</dt><dd>- End-wise section v. 2</dd><dt>18</dt><dd>- Wall v. 9</dd><dt>19</dt><dd>- Free end v. 9</dd><dt>20</dt><dd>- Press half</dd><dt>21</dt><dd>- Connecting area</dd><dt>22</dt><dd>- Tool</dd><dt>23</dt><dd>- paragraph</dd><dt>24</dt><dd>- journal</dd><dt>25</dt><dd>- Upper section v. 9</dd><dt>26</dt><dd>- Lower section v. 9</dd><dt>27</dt><dd>- Step </dd><dt>K</dt><dd>- adhesive</dd><dt>D₉</dt><dd>- Inner diameter v. 9</dd><dt>D₁₀</dt><dd>- Outer diameter v 10th</dd><dt>X</dt><dd>- Width v 14th</dd><dt>P</dt><dd>- Fit btw 9 and 10th.</dd><dt>U</dt><dd>- Pressedruck</dd><dt>F</dt><dd>- Force</dd><dt>P_F</dt><dd>- Joining force</dd><dt>l₁</dt><dd>- Longitudinal section v 10th</dd></dl>