DE102007062220A1 - Cross beam for torsion beam axle of motor vehicle, has double-walled profile with inner and outer walls that are spaced from each other, where inner and outer walls are exchanged from each other into bar sections - Google Patents

Abstract

The cross beam (3) has a double-walled profile with inner and outer walls (7, 8) that are spaced from each other. Two longitudinal links are connected with each other in a torsion-flexible manner, where the cross beam is formed from a hollow-cylindrical pipe by press-deformation. The inner and outer walls have a distance from each other, which lies within a range of 1 to 10 millimeters. End sections of the cross beam are formed approximately as a circle. The inner and outer walls are exchanged from each other into bar sections (9), which are formed at ends of two shank sections (15). An independent claim is also included for a method for manufacturing a cross beam of a torsion beam axle for a motor vehicle.

Description

Field of the invention

The The present invention is in the field of automotive engineering and relates to their genus a cross member of a Twist-beam axle for a motor vehicle, as well as a method for its production. Furthermore, it concerns one with such Cross beam fitted torsion beam axle.

State of the art

modern Motor vehicles are often equipped with twist-beam axles, because they have favorable driving characteristics with a simple technical Combine construction. Twist-beam axles comprise two wheel-guiding axles Trailing arm, which in the vehicle transverse direction by a rigid, but torsionally elastic cross beams are interconnected, which is often called "torsion profile" or "torsion bar" referred to as. In a typical design, such Torsionsprofil a U- or V-shaped cross-section.

As for example in the German publication DE 10102759 A1 a torsion profile can be produced from a hollow cylindrical tube by means of press-forming, wherein the tube is pressed by means of a press ram into a press die corresponding to the profile. Since the tube wall is pressed against each other, a torsion profile produced in this way has a double-walled structure with adjoining profile walls.

Now has been shown in practice that in a double-walled torsion profile noise during operation of the motor vehicle may occur due to a rubbing against the adjacent Profile walls are generated. These sounds can of people in the vehicle interior as unpleasant Creaking be perceived.

To solve this problem shows the international patent application WO 2006/038121 A1 a double-walled torsion profile, in which the two profile walls are each provided with projections, which keep the two profile walls at a distance. Since the contact surface between the two profile walls is reduced by the humps, a noise generation during a twisting of the torsion profile can be reduced. Nevertheless, the humps have a physical contact with the opposite profile wall, so that thereby friction noise can be generated during a twisting of the transverse profile.

task

In contrast, the object of the present invention is to provide a generic cross member a torsion beam axle for a motor vehicle available to make, through which an undesirable noise can be avoided in the twisting of the cross member. Another object is to provide a method for producing a specify such cross member.

Solution of the task

These and further objects are according to the proposal of the invention a cross member of a torsion beam axle for a motor vehicle, and by a method for its production solved with the features of the independent claims.

advantageous Embodiments of the invention are characterized by the features of the subclaims specified.

According to the invention a cross member of a torsion beam axle for a Motor vehicle shown. The crossbeam connects two wheel-leading, extending substantially in the vehicle longitudinal direction Trailing arm of the torsion beam axle in the vehicle transverse direction rigid, but torsionally elastic together.

Of the inventive cross member is distinguished essentially by making one of a hollow cylindrical Pipe-shaped double-walled profile structure with two profile walls own, with the two profile walls in the cross member are always spaced from each other and no physical contact to have. Since the two profile walls of the double-walled profile structure do not abut each other in the cross member and no physical contact with each other have, can with the cross member according to the invention advantageously a noise generation in Tordierung of the cross member can be avoided.

Especially Advantageously, the cross member at least in a middle Intermediate section a in cross section at least approximately U-shaped or V-shaped cross-section, the (at least mentally) in a U- or V-shaped inner wall and a U- or V-shaped outer wall surrounding the inner wall can be divided. Essential here is that indoor and Outer wall or the opposite Wall surfaces of the inner and outer walls, which are common form a single profile cavity, in the cross member always from each other are spaced and have no physical contact.

Of the Cross member according to the invention is or will by a Pressumformverfahren from a hollow cylindrical tube produced. The hollow cylindrical tube is in this case between two Pressing means placed, with a trained as a press stamp first Pressing means in a press die with a complementary to the ram Form trained second pressing means is pressed. In addition, will a third pressing means used before the press forming the Tube is introduced into the tube cavity. The third pressing agent causes the press forming a distance between each other opposite profile walls of the double-walled Profile structure remains. The third pressing agent may be at least one pressing tool serving as a spacer or to act on a pressurized fluid with a suitable fluid pressure.

in the Difference to the conventionally used Pressumformverfahren it is thanks in the inventive method the use of the third pressing means does not require that the profile walls of the double-walled profile structure to each other To be pressed to thereby a defined profile geometry achieve. In industrial mass production this way technically simple and inexpensive a well-defined Torsion profile with a desired distance between the produced two profile walls of the double-walled profile structure become.

at a particularly advantageous embodiment of the invention Cross member have the two profile walls of the double-walled Profile structure a (vertical) distance from each other, in the area from 1 to 10 mm. Below 1mm it is usually technical difficult after press forming a spacer used as a press tool to remove from the cavity of the profiled cross member. Above 10 mm, the torsion profiles are common used materials and material thicknesses according to experience torsionally, that is, for a killing of the torsion profile per rotation angle to be applied torque undesirably large for practical use.

In the cross member according to the invention can by a targeted choice of the distance between the two profile walls the double-walled torsion profile that for a twisting per rotation angle on zuzubende torque in the desired Be set way, with a larger wall distance with a larger torque per rotation angle and a smaller wall distance with a smaller torque per rotation angle goes hand in hand. Should smaller torques per rotation angle for the purpose a twisting of the Torsionsprofils be realized, so it is advantageous if the two profile walls a (vertical) distance from each other, which is in the range of 1 to 5 mm. Should larger torques per rotation angle for the purpose a twisting of the Torsionsprofils be realized so it is advantageous if the two profile walls (inner and outer wall) take a (vertical) distance from each other in the area from 5 to 10 mm.

Above Distance indications relate, for example, to a cross member, from a hollow cylindrical tube made of sheet steel with a diameter in the range of 70 to 120 mm, for example 90 mm, and a sheet thickness, in the range of 2 to 5 mm, in particular in the range of 2.8 to 3.8 mm, is manufactured.

at a further advantageous embodiment of the invention Cross member is this with at least approximately circularly shaped carrier ends or end sections provided, which profiled by the U- or V-shaped Intermediate section interconnected, which is a technical easy connection of the cross member to the two trailing arms allows. In addition, the cross member in this Case especially easy to twist and twist around its carrier axis be attached to the trailing arms.

The The invention further extends to a torsion beam axle of a Motor vehicle with two trailing arms, in the transverse direction by a cross member as described above torsionally elastic connected to each other. Furthermore, the invention extends to a method as described above for producing the invention Crossbeam.

embodiments

The The invention will now be described in more detail with reference to exemplary embodiments with reference to the accompanying drawings is taken. Same or equivalent elements are in the Figures designated by like reference numerals. Show it:

1 in a perspective view of a first embodiment of the torsion beam axle according to the invention;

2 a sectional view of the cross member of the torsion beam axle of 1 according to section line AA;

3 in a schematic perspective view of the cross member of the torsion beam axle of 1 with spacer tools for its manufacture;

4 in a perspective view, a second embodiment of the invention torsion beam axle;

5 a sectional view of a conventional cross member analogous to in 1 specified section line AA.

First, refer to the 1 and 2 taken, wherein a first embodiment of the torsion beam axle according to the invention is shown.

Accordingly, the total includes the reference number 1 designated twist beam axle 1 two wheel-guiding trailing arms 2 which are supported by a rigid, torsionally elastic cross member (torsion profile) 3 are connected together in the vehicle transverse direction. The crosswise straight shaped cross member 3 comprises a cross-sectionally U-shaped middle intermediate section 4 , which in cross-section circular end sections 5 connects with each other. At its end sections 5 is the crossbeam 3 with from the trailing arms 3 shaped pipe socket 6 welded.

2 shows a sectional view of the cross member 3 in the area of the middle intermediate section 4 according to section line AA in 1 ,

As 2 can be removed, the intermediate section 4 of the crossbeam 3 a U-shaped double-walled cross-section, with two substantially rectilinear leg portions 15 is provided by an approximately arcuate curved arc section 16 connected to each other. The cross profile can be in a U-shaped inner wall 7 and in a U-shaped outer wall 8th which are divided into web sections 9 at the ends of the two leg sections 15 are shaped, merge into each other. The inner wall 7 and the outer wall 8th surround a single cavity together 10 ,

The inner wall 7 of the transverse profile has two wall surfaces, namely a cavity 10 facing first wall surface 11 and one from the cavity 10 remote third wall surface 13 , Accordingly, the outer wall 8th a the cavity 10 facing second wall surface 12 , which in the two web areas 9 in the first wall surface 11 passes, and one from the cavity 10 opposite fourth wall surface 14 in the two land areas 9 in the third wall surface 13 goes on, on. The cavity 10 is through the first wall surface 11 and the second wall surface 12 the two profile walls bounded.

In the profiled intermediate section 4 of the crossbeam 3 take the two of the cavity 10 facing wall surfaces 11 . 12 from inside and outside wall 7 . 8th always a distance from each other, ie they are not at any point of the intermediate section 4 or the cross member 3 at. The (vertical) distance between the first wall surface 11 the inner wall 7 and the second wall surface 12 the outer wall 8th varies over the cross section of the intermediate section 4 , However, is at least 2 mm, so that a rubbing or a physical contact between the inner and outer wall during a twisting of the cross member 3 can be safely avoided.

In the area of the leg sections 15 have inner and outer wall 7 . 8th a distance of about 2-3 mm from each other, whereas in the area of the bow section 16 Inside and outside wall occupy a distance of about 7-8 mm, which in a targeted way for a twisting of the cross member 3 is set for each angle of rotation applied torque. Should that for a twisting of the cross member 3 For each angle of rotation to be applied torque is reduced, so this is only the distance from the inner and outer wall in particular in the region of the arc section 16 to reduce. In the opposite case, the distance between the inner and outer wall in particular in the region of the arc section 16 to enlarge. In the embodiment shown, the torque to be applied per angle of rotation is, for example, in the range of 300 to 700 Nm / degree.

The crossbeam 3 is or is made from a hollow cylindrical tube by means of a Pressumformverfahrens. The tube used for this purpose is made of sheet steel and has a diameter of 100 mm and a wall thickness of 3.0 mm.

To produce the cross member, the tube is pressed by a press ram into a correspondingly shaped press die, to thereby form the intermediate section 4 U-shaped profile. In 3 is the profiled cross member 3 the torsion beam axle of 1 with a U-shaped profiled intermediate section 4 and the two circular end portions 5 shown.

Prior to pressing, spacer tools serving as spacers are inserted into the cavity of the tube 17 . 18 inserted from the two pipe ends ago and pulled out again after the pressing process. The two spacer tools 17 . 18 are each with a U-profile tool section 19 which has a U-shaped cross-section in cross-section, and a circular profile tool section 20 , which has a circular cross-section in cross-section provided. The pipe wall is pressed by the press die on the two spacer tools 17 . 18 pressed, with the geometric shape of the two U-profile tool sections 19 the middle intermediate section 4 of the crossbeam 3 U-shaped profiled. This is due to the thickness of the U-profile tool sections 19 the two spacer work witness 17 . 18 the distance between inner and outer wall 7 . 8th of the crossbeam 3 specified. In the area of the circular profile tool sections 20 the two spacer tools 17 . 18 the tube remains circular. The two spacer tools 17 . 18 thus cause the press forming a defined distance between the inner and outer wall remains. A minimum distance of 2 mm between inner and outer wall allows easy removal of the two spacer tools 17 . 18 from the finished profiled cross member 3 ,

In 4 is shown in a perspective view of a second embodiment of the torsion beam axle according to the invention. It will only be the differences to that in the 1 to 3 illustrated first embodiment of the invention explained. Incidentally, reference is made to the comments made on the first embodiment. In the 4 shown torsion beam axle 1 is with a cranked cross member 3 provided, the crank in the installed state provides an enlarged space for a propeller shaft. In addition, the cross member 3 in comparison to the cross member of 1 twisted about its longitudinal axis, wherein the opening of the U-profile is directed to the vehicle top. This ensures that the rolling center of the beam axle of the vehicle is lower than in the 1 shown torsion beam axis, whereby a corresponding roll or roll behavior of the motor vehicle can be obtained in the desired manner.

In 5 is a sectional view of a conventional cross member shown, wherein the sectional view of the sectional view of 2 corresponds in an analogous manner. The total with the reference number 101 designated cross member comprises an inner wall 102 and an outer wall 103 , each in web sections 104 merge. In the conventional cross member 101 The inner and outer walls of the double-walled profile structure are in the region of the leg sections 105 largely and in the area of the two leg sections 105 interconnecting arc section 106 completely on. In a twisting of the cross member 101 can by rubbing against the inner and outer wall 102 . 103 disadvantageously a creaking noise occur.

By a distance between inner and outer wall of the double-walled Profile structure allows the invention Cross member in a simple way that the generation of a unwanted creaking noise when killing of the cross member is avoided. In an advantageous way this can improve the ride comfort in the passenger compartment. In addition, by a suitable choice of the distance between indoor and outer wall a setting of the angle of rotation for twisting the cross member required torque possible.

1

Beam axle

2

Trailing arm

3

crossbeam

4

intermediate section

5

end

6

pipe socket

7

inner wall

8th

outer wall

9

web section

10

cavity

11

first wall surface

12

second wall surface

13

third wall surface

14

fourth wall surface

15

leg portion

16

arc section

17

first Spacer tool

18

second Spacer tool

19

U-shaped tool section

20

Circular profile tool section

101

crossbeam

102

inner wall

103

outer wall

104

web section

105

leg portion

106

arc section

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10102759 A1 [0003]
• - WO 2006/038121 A1 [0005]

Claims (8)

Cross member ( 3 ) a torsion beam axle ( 1 ) for a motor vehicle having two trailing links ( 2 ) torsionally elastic and is formed from a hollow cylindrical tube by means of press forming, characterized in that the cross member ( 3 ) has a double-walled profile whose profile walls ( 7 . 8th ) are always spaced from each other. Cross member ( 3 ) according to claim 1, characterized in that the cross member at least in an intermediate section ( 4 ) a cross-section at least approximately U- or V-shaped transverse profile with an inner and outer wall ( 7 . 8th ) having. Cross member ( 3 ) according to one of the two claims 1 to 2, characterized in that the two profile walls ( 7 . 8th ) are at a distance from one another within the range of 1 to 10 mm. Cross member ( 3 ) according to one of the two claims 1 to 2, characterized in that the two profile walls ( 7 . 8th ) have a distance from each other which is in the range of 1 to 5 mm. Cross member ( 3 ) according to one of the two claims 1 to 2, characterized in that the two profile walls ( 7 . 8th ) are spaced apart from each other within the range of 5 to 10 mm. Cross member ( 3 ) according to one of claims 1 to 5, characterized in that it has at least approximately circular end portions ( 5 ) is provided. Twist-beam axle ( 1 ) of a motor vehicle with two trailing arms ( 2 ) transversely through a cross member ( 3 ) are torsionally connected to one another according to one of claims 1 to 6. Method for producing a cross member ( 3 ) a torsion beam axle ( 1 ) for a motor vehicle with a dop pelwandigen profile whose profile walls ( 7 . 8th ) are always spaced from each other, in which a hollow cylindrical tube is pressed by a first pressing means in a second pressing means, wherein prior to pressing a third pressing means, which defines a selectable distance between the two profile walls, is introduced into the cavity of the tube.