DE102011053927A1 - Spring arm for chassis of motor vehicle, has base portion having cross section with upper side and lower side extending in arc-shape, in which upper side and lower side are interconnected through other two sides that are parallel - Google Patents

Abstract

The spring arm (1) has a base portion (2) which is formed by a hollow profile. The base portion in longitudinal portion has a cross section having an upper side and lower side opposite the upper side extending in an arc-shape. The upper side and the lower side are interconnected through the other two sides which are parallel. The other two sides are extended parallel in portion of the walls of base portion so that through-holes are formed for receiving the functional element. An independent claim is included for method for manufacturing spring arm.

Description

The invention relates to a spring link for a chassis of a motor vehicle.

In the chassis of a motor vehicle spring links are used. These are essentially rigid components that serve to support the wheel on the chassis and to guide in one or more directions, which requires the support of high forces and moments. Spring link regularly have a connection for a suspension spring, a shock absorber or a combined spring-shock absorber element and a pivotable about an axis connection to the chassis on one side and to the wheel on the other side.

The driving behavior of a motor vehicle is decisively influenced by the position of the wheel in the different driving situations. Therefore, it is important that the position of the wheel during rebound and rebound is defined essentially only by the kinematics of the suspension and less by (unwanted) deformations of the individual elements of the suspension, including the spring link. Spring link should therefore the highest possible stability and rigidity, i. In particular, a high moment of resistance, but at the same time the lowest possible weight, since spring links are part of the unsprung mass of the motor vehicle. These conflicting requirements have meant that spring links are usually designed today as a geometrically complex shaped hollow components.

For the production of such spring link is usually resorted to formed by pressing shell components, which are joined together by welding to form the hollow member. However, this production is associated with a considerable amount of work.

Therefore, alternative production methods have been developed in order to reduce the production costs for spring links designed as hollow components.

From the EP 1 232 029 B1 For example, it is known to construct a spring link based on an extruded hollow profile made of high-strength aluminum, which initially has a rectangular cross-section with adjoining walls of different thickness. The further processing of this hollow profile is then exclusively with mechanical cold processing, such as stretch bending, pressing, cutting and punching.

From the EP 1 364 817 A1 is also known to produce a spring link by hydroforming of a semi-finished tube.

Based on this prior art, the present invention seeks to further improve a spring link, in particular with regard to its structural and functional properties. Preferably, an output hollow profile, from which the spring link is produced by essentially simple forming work, should already have an output cross-section that is constant over the length, in which the dimensions required on the finished spring link are already largely realized. The output cross-section should also be such that it favors the desired deformation. Overall, this results in a simplified, less error-prone production.

This object is solved by the subject matter of independent patent claim 1 and by a method according to independent claims 13 and 14. Advantageous embodiments of the spring link invention are the subject of the dependent claims and will become apparent from the following description of the invention.

The invention is based on the idea to improve the structural and functional properties of a spring link by a targeted shaping of the cross sections of individual longitudinal sections which follow one another in the longitudinal direction of the spring link. This is based on a one-piece, preferably extruded hollow output profile, which is further processed only by mechanical deformation. In this case, a cross section for the initial profile is shown, which has good structural and functional properties in one or more - as large as possible - sections without further deformation for a spring link and also by as few and / or simple reshaping a further improvement of the structural and functional properties and the conditions for the connection of other elements of the chassis allows. Already the design of the output cross-section of the initial profile thus takes the intended final result, namely the finished spring link, in view.

An inventive spring link for a chassis of a motor vehicle therefore has a base body in the form of a metallic hollow profile, which is formed in particular from an output hollow profile with an initially constant over its length output cross-section, preferably by an aluminum extruded profile by targeted transformation. The spring link is characterized in that the base body in at least one longitudinal section of the spring link has a first cross section with a first side and a second side opposite the first side. The second side extends at least in one area, but preferably completely, arched and arched outwards. Furthermore, the first cross-section has a third side and a fourth side, which connect the first side and the second side as lateral connection sides and which extend substantially parallel at least in a partial region. The first cross section is preferably identical to the cross section of the output hollow profile, with the possible exception of introduced recesses, through holes or separated projections. The longitudinal section of the transverse link, which is formed by the first cross section, has therefore preferably undergone no deformation in relation to the output hollow profile.

Due to the arcuate, preferably outwardly curved design of the second side, which is preferably the underside of the spring link (this in the installed state of the spring link so to the road), a high mechanical stability in the direction of the vertical axis of the motor vehicle is achieved. In addition, the arcuate design of the second side may still have advantages, provided that the hollow profile in a longitudinal section, in which this first the inventive first cross-section, in particular the cross section of the hollow output profile, has been reshaped with the aim of reducing the height, which is done by a simple pressing can. This will be described below.

Due to the parallel alignment of regions of the third and fourth side of the first cross section, the connection of functional components can be achieved in a simple manner, for which purpose the longitudinal sections of the base body formed by these connecting sides can preferably have through openings.

In a preferred embodiment of the spring link according to the invention can be provided that the first side is substantially flat. In this case, the first side laterally project beyond the attachment points of the third and fourth side of the spring link.

In a further preferred embodiment of the spring link according to the invention, provision can be made for the third and the fourth side of the first cross-section to extend in a diverging manner starting from the parallel section in at least a second area of these sides. Preferably, the diverging section connects the parallel portions of the third and fourth sides with the first side, so that in this area, the distance between the third and fourth sides widens upward. As a result, once again advantageous structural properties and advantageous deformation behavior during press forming in the vertical direction (vertical direction) can be achieved by moving the first and the second side toward one another. In addition, this has an increase in the internal volume of the base support in the adjoining to the first side volume volume, whereby the recording and attachment of a functional element, in particular a shock absorber or a combined spring-shock absorber element is facilitated.

In order for said functional element, in particular for the end of a spring-shock absorber element, to protrude into the inner volume of the base support, it is provided that a recess is provided in the wall of the base body forming the first side, which recess connects the functional element between the parallel areas the third and fourth page allows. For this purpose, the recess in a longitudinal portion of the first side is provided, which is in the vicinity, preferably in the shortest distance of the through holes, which is provided in the parallel wall portions of the third and fourth sides. The passage openings thus serve preferably for the rotatable connection of the spring-shock absorber element of the motor vehicle projecting into the interior volume of the main body.

In a preferred embodiment of the spring link according to the invention can be provided that the base body in at least one second longitudinal section has a second cross-section with a first side and a second side opposite the first side, these two sides each extend at least in one area, preferably completely arcuate , This refinement is again distinguished by advantageous structural properties, in particular if this is provided at least one longitudinal section for the connection of the spring link to the wheel carrier or to the chassis of the motor vehicle. Preferably, the spring link on two second longitudinal sections, which each form the two end portions of the spring link.

For this purpose, it can then be provided, in turn, that the third and the fourth side of the second cross section, which connect the first and the second side of this cross section, extend substantially parallel at least in one region, preferably over the entire length, preferably in parallel extending portion of the third and the fourth side of the second longitudinal section forming the second cross section through openings for receiving a functional element, in particular a bearing bush are formed.

The at least one second longitudinal section of the spring link characterized by the second cross section can preferably be generated by simple press-forming of the main body in the horizontal direction (transverse direction), if the Base body in this section previously has a cross-section corresponding to the first cross-section, wherein any disruptive during the forming process cross-sectional areas, in particular those forming the first side and laterally project beyond the attachment points of the third side and / or the fourth side to the first side , before the forming process can be removed.

In a further preferred embodiment of the spring link according to the invention the base body in at least one further longitudinal section on a further cross section with a first side and a first side opposite the second side, said two sides at least in one area, in particular over the full width, parallel to each other run. This longitudinal section of the spring link can be produced by a simple press-forming of the starting cross section of the main body in this longitudinal section, if the main body before the forming process had a cross section substantially corresponding to the first cross section, in particular a corresponding cross section of the output hollow profile cross section, in turn, any during the forming process disturbing cross-sectional areas, in particular those that form the first page, can be removed before the forming process.

As a result, it is possible to use the spring link according to the invention starting from an output hollow profile in one or more sections by simple press-forming, e.g. between two preferably parallel, flat molds, optionally after previous trimming, in its outer dimensions, ie in particular its width (horizontal deformation in the transverse direction) and / or its height (vertical deformation in the vertical direction), to be reduced by the inventive shape of the first output cross-section the output hollow profile remain even after forming advantageous structural or functional properties. The space requirements of other elements of the chassis of the motor vehicle or on the spring handlebars still to be arranged additional parts can be met, without causing a significant manufacturing effort or a relevant negative impact on the stability of the spring arm would go along.

In particular, the concrete shaping of the starting cross-section with a second side, which is arched outward, and / or with a third and fourth side extending parallel to each other over a partial region, which after the parallel portion extending outwardly bent and divergent, allows an advantageous deformation behavior. The "kink" located in the third and fourth sides assists that the previously parallel portion of the third and fourth sides is respectively bent inward during the press-forming operation and the sides subsequently move toward one another. The height reduction achieved with the transformation is thus not accompanied by a width increase. At the same time is achieved by the convex second side, that this does not migrate into the inside of the profile during press forming and then curved to the inside, which would reduce the stability of the spring arm in this longitudinal section.

During manufacture, the spring link according to the invention is formed from a preferably extruded hollow output profile of an aluminum material that has over its entire length provided for the spring link first length corresponding to the first cross-section output cross-section, and then the other, defined by different cross-sections longitudinal sections are produced by simple forming measures , The forming process is preferably exclusively in a cold forming. Depending on the degree of deformation, however, can also be resorted to a hot deformation.

The invention will be explained in more detail with reference to an embodiment shown in the drawings.

In the drawings shows:

1 a spring link according to the invention in an isometric view;

2 the spring link according to 1 in a side view;

3 the spring link according to 1 in a schematically illustrated installation situation on the motor vehicle;

4 a section through the spring link according to 1 to 3 along the section IV-IV in 2 ;

5 a section through the spring link according to 1 to 3 along the section plane VV in 2 ;

6 a section through the spring link according to 1 to 3 along the cutting plane VI-VI in 2 ;

7 a section through the spring link according to 1 to 3 along the sectional plane VII-VII in 2 ; and

8th a section through the spring link according to 1 to 3 along the section plane VIII-VIII in 2 ,

The 1 to 7 show a spring link according to the invention 1 for a chassis of a motor vehicle after completion in different views or according to the in 2 indicated cutting lines.

The spring link 1 includes a main body 2 , which is formed as a one-piece hollow body. The main body 2 has a complex shell geometry with different cross sections in its various longitudinal sections.

In two longitudinal sections, the main body 2 in the 5 or 7 illustrated cross-section, wherein the in 5 shown cross section of the in 7 shown only by a recess and through holes for a bearing axis 9 , which each serve to receive a shock absorber, different from each other, but not by changing the course of the walls deformation.

The said cross-section is through a flat first upper side 3 , an arcuate, outwardly arched second lower side 4 that's the first page 3 and two substantially vertically extending connecting sides, that of the third side 5 and the fourth page 6 are formed and represent the side surfaces of the spring link. The third page 5 and the fourth page 6 each have a first to the second page 4 adjacent subarea, in which these two connection pages 5 . 6 essentially parallel to each other. Following on from a "kink", this second partial area is adjoined by a second partial area, in which the two connecting sides are in the direction of the first side 3 run divergently. The wall thickness of all four sides is preferably the same and constant over the entire circumference.

The first cross section according to 7 represents the output cross section of a hollow output profile before the completion of the spring link. From this output cross section is the main body 2 formed with its other longitudinal sections by forming, ie all cross sections described below are generated from this by forming between dies, provided that the cross section to be achieved for a particular longitudinal section is not achievable only by trimming and the introduction of recesses or holes in the output cross-section. Optionally, the forming thus takes place only after prior removal of a portion of the initial profile, such as in 7 shown the connection pages 5 . 6 laterally projecting portion, or after previous introduction of a recess instead.

In two ends in the longitudinal direction of the main body 2 or of the spring link 1 lying longitudinal sections is the deformation by a press forming in the transverse direction, wherein the third side 5 and the fourth page 6 of the cross section in these areas are moved toward each other after the portion of the upper, first side 3 that has the connection points that connect the third page 5 and the fourth page 6 in the first page 3 pass over, has been removed. This results in the in the 4 illustrated second cross section, in which the first, upper side 3 and the second, lower side 4 extend curved with substantially the same radius of curvature outwards, while the respective third side 5 and the respective fourth page 6 essentially parallel to each other. Overall, a kind of oval with parallel side surfaces. Essential purpose of this compression of the end longitudinal sections of the body 2 is the achievable reduction in the width of the spring link 1 , which brings advantages for its connection to other elements of the landing gear, and the creation of parallel surfaces between which a bearing bushing 7a . 7b can be easily absorbed.

Accordingly, the main body 2 provided in the two end, characterized by the second cross-section sections with two overlapping through holes, in which in the longitudinal sections of the bearing bushes 7a . 7b are introduced, which serve the connection of the spring link to the wheel and to the chassis. The through holes were introduced after forming these sections by a mechanical separation process. Preferably, the passage openings are introduced by punching. The bearing bush 7a . 7b includes a in a receiving sleeve 11 lying rubber bearing.

In a central section of the spring link 1 indicates the basic body 2 in the 6 represented further (third) cross-section, which is characterized by a pressing in the vertical direction of the present in this area before the forming output cross-section ( 7 ). The pressing took place in the vertical direction on the upper, first side 3 this cross section with an outwardly curved pressing tool, so that in the 1 and 2 recognizable arcuate recess in the top course of the body results. This indentation serves to collide the spring link 1 with another element of the motor vehicle during compression of the spring link 1 to avoid or to increase the possible travel. The orientation or inclination of the resulting and later the spring receiving surface is also on the intended in driving orientation of the spring axis 12 ( 3 ) oriented. The compression thus reduces the height of the spring link in a simple manner 1 In this section.

The stability of the spring link 1 is negatively affected only to a small extent. This will be in the case of 6 Cross-section achieved inter alia also by the fact that the third page 5 and the fourth page 6 (Connecting sides) buckle inward during forming, ie to move towards each other. At the same time, the outward curvature ensures the lower, second side 4 in that the connecting sides buckling inwards during the forming 5 . 6 the lower, second side 4 do not pull into the hollow section in such a way that the lower, second side 4 would be curved inward after the forming process, which was accompanied by a reduction of the moment of resistance of the cross section. The reduction in height by the compression is thus also not associated with a broadening of the spring link in this section.

In one of the longitudinal sections of the main body formed by the initial cross section 2 , in particular the longitudinal section according to the in 5 shown cross-section, this points in the two of the third page 5 and the fourth page 6 formed side walls overlapping through holes, the receiving a preferably of a bearing pin 8th serve formed bearing axis. About this bearing pin 8th becomes the spring link 1 connected to a shock absorber of the chassis. In this case, one end of the shock absorber protrudes through one in the upper, first side 3 introduced recess 9 (see. 1 and 3 ) a little way into that of the main body 2 trained inside volume, which is favored by the diverging extending portions of the side walls. The parallel sections of the side walls 5 . 6 In this case, starting from the initial profile, parallel bearing surfaces are available for the bearing pin, thereby making it possible to attach a bearing shaft without additional deformation of the initial profile in this longitudinal section.

In the wall formed by the tops of the body 2 is in a central section (area of section VIII-VIII in 2 ) also an additional 8th apparent, preferably circular opening 10 provided, which serves that in 3 and 8th exemplified as a tube-stump Federstützdom illustrated spring receptacle 13 can be added to the support of the spring from the cross section of the spring link. 8th also illustrates the below the opening 10 additionally provided recess 14 , via which the accessibility or operability of a spring tensioner (not shown) is ensured. The recess 14 can - as well as the other recesses described above - are introduced by cutting or punching, but it is preferably produced by machining, in particular by milling.

The deformation of the body 2 takes place in the illustrated embodiment in the cold state, with a transformation in the semi-warm or warm state is possible and - especially with a high degree of deformation - may be useful. In addition to the described press forming certain longitudinal sections are for the realization of in particular in 2 recognizable, overall curved course of the spring link 1 applied to the skilled worker forming processes.

LIST OF REFERENCE NUMBERS

1

spring link

2

body

3

upper, first page

4

lower, second side

5

third side (connection side)

6

fourth page (connection page)

7a

bearing bush

7b

bearing bush

8th

bearing bolt

9

Recess for shock absorber mount

10

Opening for spring support dome

11

receiving sleeve

12

spring axis

13

spring mount

14

Recess for spring compressor

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1232029 B1 [0006]
• EP 1364817 A1 [0007]

Claims (14)

Spring link ( 1 ) for a chassis of a motor vehicle with a base body formed by a hollow profile ( 2 ), characterized in that the basic body ( 2 ) in at least one longitudinal section a first cross section with a first side ( 3 ), a second page opposite the first page ( 4 ), which runs in an arcuate manner at least in a partial region, wherein the first side ( 3 ) and the second page ( 4 ) on a third page ( 5 ) and a fourth page ( 6 ), which run parallel at least in a partial area, are interconnected. Spring link ( 1 ) according to claim 1, characterized in that in the parallel portion in the third ( 5 ) and fourth page ( 6 ) forming walls of the body ( 2 ) Passage openings are formed for receiving a functional element. Spring link ( 1 ) according to claim 1 or 2, characterized in that the first page ( 3 ) just runs. Spring link ( 1 ) according to one of the preceding claims, characterized in that the third ( 5 ) and fourth page ( 6 ) extend divergently in at least a second portion starting from the parallel portion. Spring link ( 1 ) according to claim 4, characterized in that the diverging section is the parallel section of the third ( 5 ) and fourth page ( 6 ) with the first page ( 3 ) connects. Spring link ( 1 ) according to claim 2 or one of the claims dependent on claim 2, characterized in that above the one in the third side ( 5 ) and the fourth page ( 6 ) forming walls provided through holes a recess ( 9 ) in which the first page ( 3 ) forming wall of the body ( 2 ) is provided. Spring link ( 1 ) according to one of the preceding claims, characterized in that the basic body ( 2 ) in at least one longitudinal section a second cross-section with a first side ( 3 ) and one of the first page ( 3 ) opposite second side ( 4 ), each of which extends in an arcuate manner at least in one section. Spring link ( 1 ) according to claim 7, characterized by the first page ( 3 ) and the second page ( 4 ) of the second cross-section connecting third side ( 5 ) and fourth page ( 6 ), which are essentially parallel. Spring link ( 1 ) according to claim 8, characterized in that in the parallel portion of the third side ( 5 ) and fourth page ( 6 ) of the second cross section through openings for receiving a bearing pin ( 8th ) are formed. Spring link ( 1 ) according to one of the preceding claims, characterized in that the basic body ( 2 ) in at least one longitudinal section a further cross section with a first side ( 3 ) and one of the first page ( 3 ) opposite second side ( 4 ), which run parallel in at least one section. Spring link according to claim 10, characterized by the first side ( 3 ) and the second page ( 4 ) connecting third page ( 5 ) and fourth page ( 6 ) of the further cross section, which do not run parallel. Spring link according to one of claims 7 or 10 or one of the claims dependent on claim 7 or 10, characterized in that the first sides ( 3 ) of the first, second and / or further cross section has the same upper wall of the basic body ( 2 ) train. Method for producing a spring link ( 1 ) according to claim 7 or one of the dependent claims on claim 7, characterized in that the second longitudinal section is produced by forming an output hollow profile with an output cross-section, wherein the second longitudinal section before forming a first section substantially corresponding cross-section. A method of manufacturing a spring link according to claim 10 or claims dependent on claim 10, characterized in that the further section is produced by forming, the further section having a cross section substantially corresponding to the first section prior to pressing.

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