DE102018104887A1 - Torsion bar and method for producing a torsion bar for a roll stabilizer - Google Patents

Abstract

A torsion bar spring (1) of an active roll stabilizer comprises three sections (2,3,4), namely two end sections (2,3), of which a first section (2) for connection to an electromechanical actuator and a second section (3) articulated connection is provided with a wheel carrier, as well as one the two end portions (2,3) connecting, at least partially formed as a torsion spring central portion (4), wherein at least one of the three sections (2,3,4) at least partially formed as additively manufactured metal part is.

Description

The invention relates to a provided for use in an active roll stabilizer of a motor vehicle torsion bar spring. Likewise, the invention relates to a method for producing such a torsion spring.

An active, electro-mechanical anti-roll bar for a motor vehicle is for example from EP 2 142 391 B1 known. An actuator device of this roll stabilizer comprises an electric motor and a transmission gear. To the actuator device two stabilizer parts are connected, which comprise torsion sections and each extending to a suspension.

A method of manufacturing a roll stabilizer housing is disclosed, for example, in U.S. Patent No. 5,376,842 DE 10 2016 200 177 A1 described. The roll stabilizer housing has a housing base, on the outer surface of which there is an annular peripheral structuring, which supplies useful information in the manufacture of the roll stabilizer.

In the documents DE 10 2014 203 241 A1 and DE 10 2014 203 242 A1 are various positive couplings between an actuator of a roll stabilizer and stabilizer parts, that is torsion bars, described.

In contrast to the solutions according to the latter two documents are in a roll stabilizer after the DE 10 2015 222 068 A1 Torsion bar springs materially connected to an output shaft of an electromechanical actuator.

The invention has for its object to further develop an active, electro-mechanical anti-roll bar for a chassis of a motor vehicle over the prior art, especially under production engineering aspects.

This object is achieved by a torsion bar spring with the features of claim 1. Also, the object is achieved by a method for producing a torsion bar according to claim 7. The torsion bar is suitable for use in an active roll stabilizer according to claim 6. Embodiments and advantages of the invention explained below in connection with the production method also apply correspondingly to the devices, that is to say the torsion bar spring and the roll stabilizer, and vice versa.

The torsion spring comprises three sections, namely two end sections, of which a first section is provided for connection to an electromechanical actuator and a second section for articulated connection to a wheel carrier, and a central section connecting the two end sections and formed at least partially as a torsion spring. According to the invention, at least one of the three sections of the torsion bar is at least partially formed as an additively manufactured metal part.

With regard to additive manufacturing methods is exemplified in the DE 10 2014 014 202 A1 pointed. According to this document, among other functional components such as spring elements by laser powder build-up welding can be built.

The technological background will continue on the documents DE 10 2016 212 080 A1 and EP 3 051 068 A1 noted that relate to additively manufactured parts for aircraft.

The WO 2008/125497 A1 discloses a manufacturing method for high temperature components, which are also intended for use in aircraft. In the context of this manufacturing process metal powders are used, which were obtained by means of precipitation reactions.

Data processing methods in connection with additive manufacturing are for example in the documents DE 10 2016 210 643 A1 and DE 10 2016 103 118 A1 disclosed.

In addition to purely additive processes, combinations of additive and other, for example, reshaping production come into consideration for the production of sections of the torsion bar spring or for the manufacture of the entire torsion bar spring. Regarding the basic possibility to combine additive manufacturing with forming production, is on the DE 10 2016 111 047 B3 directed.

As part of the manufacture of the torsion bar spring material can be applied to a base body, for example, a flange piece which is provided for coupling with the electromechanical actuator of the roll stabilizer, in individual layers. In this case, the workpiece can be rotated along the main axis of the torsion bar to be manufactured, that is to say the workpiece, wherein cross-section variations and curved areas of the torsion bar can be realized in a simple manner by varying feeds and material addition.

According to a first possible embodiment, only a single end section, that is to say either the end section provided for connection to the electromechanical actuator or the connection to the wheel carrier, is produced partially or completely additively. Likewise, both end portions of the torsion bar spring can be made at least partially additive.

According to a further possible embodiment of the middle acting as a torsion spring portion of the torsion bar spring is made additive. In this case, the two end sections can either be produced by other methods, for example forming and / or machining methods, or else by additive methods or by any combination of the methods mentioned.

The portion of the torsion bar spring designed as an additive metal part may have any outer contour, for example a conical shape or a cylindrical shape. Preferably, the additively manufactured metal part has at least one cavity.

According to a possible embodiment, a honeycomb structure is formed by the additive-manufactured part. This honeycomb structure can either fill a partial region of the cross section or the entire cross section of the section of the torsion bar spring which is made additive.

• 1 eine Drehstabfeder in perspektivischer Ansicht,
• 2 einen mittleren Abschnitt der Drehstabfeder nach 1,
• 3 eine Wabenstruktur innerhalb des mittleren Abschnitts,
• 4 einen ersten, zur Verbindung mit einem Aktuator vorgesehenen Endabschnitt der Drehstabfeder,
• 5 eine alternative Gestaltung des ersten Endabschnitts der Drehstabfeder,
• 6 einen zweiten zur Verbindung mit einem Radträger vorgesehenen Endabschnitt der Drehstabfeder nach 1,
• 7 ausschnittsweise eine alternative Gestaltung des zweiten Endabschnitts der Drehstabfeder.

Several embodiments of the invention will be explained in more detail with reference to a drawing. Herein show:

• 1 a torsion bar in perspective view,
• 2 a middle section of the torsion bar after 1 .
• 3 a honeycomb structure within the middle section,
• 4 a first end portion of the torsion bar spring provided for connection to an actuator;
• 5 an alternative design of the first end portion of the torsion spring,
• 6 a second provided for connection to a wheel carrier end portion of the torsion bar after 1 .
• 7 fragmentary an alternative design of the second end portion of the torsion bar spring.

The 1 shows a total with the reference numeral 1 characterized torsion bar spring, which is intended for use in a roll stabilizer of a motor vehicle, not shown. With regard to the basic function of such a roll stabilizer, reference is made to the cited prior art. In addition to the torsion bar spring 1 to 1 the roll stabilizer comprises a further torsion bar spring, wherein both torsion bar springs are also referred to as stabilizer halves. This designation does not imply that both stabilizer halves are the same length.

The torsion bar spring 1 includes three interconnected section 2 . 3 . 4 , At the sections 2 . 3 these are end sections of the torsion bar spring 1 , Here is a first section 2 for connection to the electromechanical actuator, also referred to as actuator, provided the roll stabilizer, while the second end portion 3 is provided for articulated connection with a likewise not shown wheel carrier. The two end sections 2 . 3 are through a middle section 4 , which is also referred to as Torsionsabschnitt connected to each other. Details of the torsion section 4 go out of the 2 and 3 out.

In the embodiment, each of the three sections 2 . 3 . 4 manufactured using additive processes. For the entire torsion bar spring 1 it is a metal part. Additive applied material of the torsion bar 1 may initially be in the form of powder or wire. The known advantages of additive manufacturing processes, in particular the high flexibility, are particularly useful in the production of small batches or individual parts. However, it may be in the torsion bar 1 also a part produced in mass production act. In this case, specific advantages of additive processes, with regard to weight savings which can be achieved with high component complexity and at the same time excellent mechanical properties, are of importance.

At the first end section 2 is a flange 5 with a frontal toothing 6 recognizable. The gearing 6 serves the torque transmitting connection of the torsion bar spring 1 with the actuator of the roll stabilizer. At the flange 5 it is a metal part produced in a conventional manner, namely by forming and / or machining operations. To the flange 5 closes a transition section 7 which has a material connection to the middle section 4 manufactures.

The middle section 4 includes two hollow sections 8th . 9 , which at the first end portion 2 or at the second end portion 3 connect. Between the hollow sections 8th . 9 is a honeycomb section 10 , whose honeycomb structure is made of metal by an additive method. In the honeycomb section 10 are hexagonal honeycombs 11 formed, as detailed 3 evident. The extent of the honeycomb section 10 within the middle section 4 can last longer than in 2 be sketched. In particular, the honeycomb section 10 directly to the transition section 7 connect.

At the the flange 5 opposite end of the torsion bar 1 there is another transitional section 12 which is the second end section 3 attributable to. At the second transitional section 12 the torsion bar rejuvenates 1 - in considered a possible projection direction - the end section 3 out. The conclusion of the second end section 3 makes a massive tail 13 in which there is a hole 14 located. As well as the flange 5 is the tail 13 manufactured in a conventional manner by forming and / or machining processes. In contrast, the transition section 12 , which on the tail 13 connects, manufactured additive.

Both concerning the transitional section 7 as well as what the transitional section 12 relates to geometrically complex and geometrically simpler variants, each using additive manufacturing processes, can be realized. In 4 according to the design 1 shows is a ribbing 15 within the transitional section 7 recognizable. In contrast, in the simplified design according to 5 no such ribbing available.

Out 6 goes an asymmetrical concave cross-sectional configuration of the transition section 12 out. An alternative, simplified design of the transition section 12 is in the variant 7 outlined. In both cases, the transition section 12 manufactured additive.

LIST OF REFERENCE NUMBERS

1

Torsion bar

2

first end section

3

second end section

4

midsection

5

flange

6

gearing

7

Transition section

8th

hollow section

9

hollow section

10

honeycomb section

11

honeycomb

12

Transition section

13

tail

14

drilling

15

ribbing

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 2142391 B1 [0002]
• DE 102016200177 A1 [0003]
• DE 102014203241 A1 [0004]
• DE 102014203242 A1 [0004]
• DE 102015222068 A1 [0005]
• DE 102014014202 A1 [0009]
• DE 102016212080 A1 [0010]
• EP 3051068 A1 [0010]
• WO 2008/125497 A1 [0011]
• DE 102016210643 A1 [0012]
• DE 102016103118 A1 [0012]
• DE 102016111047 B3 [0013]

Claims (10)

A torsion bar spring (1) of an active roll stabilizer, comprising three sections (2, 3, 4), namely two end sections (2, 3), of which a first section (2) for connection to an electromechanical actuator and a second section (3) articulated connection is provided with a wheel carrier, and a the two end portions (2,3) connecting, at least partially formed as a torsion spring central portion (4), characterized in that at least one of the three sections (2,3,4) at least partially as an additive manufactured metal part is formed. Torsion bar spring (1) to Claim 1 , characterized in that the section formed as an additive metal part (2,3,4) has an at least partially conical shape. Torsion bar spring (1) to Claim 1 or 2 Characterized in that the additive designed as a metal-made portion (2,3,4) has an at least partially cylindrical shape. Torsion bar (1) according to one of Claims 1 to 3 , characterized in that the additively manufactured section (2, 3, 4) has a honeycomb structure. Torsion bar spring (1) to Claim 4 , characterized in that the honeycomb (11) fill the entire cross-section of the additively manufactured portion (2,3,4). Active anti-roll bar for a motor vehicle, comprising an electromechanical actuator and two each provided for articulated connection with a wheel carrier, by the actuator against each other twistable torsion bars (1) according to Claim 1 , A method of manufacturing a torsion bar spring (1) for an active roll stabilizer, wherein at least a portion (2,3,4) of the torsion bar spring (1) is made by an additive manufacturing process. Method according to Claim 7 , characterized in that the additive manufacturing is carried out by laser deposition welding. Method according to Claim 7 or 8th , characterized in that the additive manufacturing includes a precipitation reaction. Method according to one of Claims 7 to 9 , characterized in that the additive manufacturing includes the production of hexagonal honeycombs (11) within the portion (2,3,4) of the torsion bar spring (1).

Images