DE102019128062A1 - Primary part with one-piece flexplate pressed into the primary flywheel - Google Patents

Abstract

The invention relates to a dual-mass flywheel (1) which is used in a drive train of a motor vehicle powered by an internal combustion engine, consisting of a primary part (2) and a secondary part (3), which are connected via a spring damping device (5) and can be rotated about an axis of rotation (4) are rotatable to a limited extent relative to one another, with arc springs (7) inserted in a spring channel (6) of the spring damping device (5) being supported on stops of the primary part (2) and a carrier flange (18) of the secondary part (3) and the multi-part primary part (2 ) includes a disk-like, axially elastic flexplate (10) which is fastened radially on the inside to the internal combustion engine and is connected radially on the outside to a primary flywheel (13) and an outer angled leg (11) of the one-piece flexplate (10) from a cylindrical section (12 ) the primary flywheel (13) is enclosed for the torsionally rigid attachment of the flexplate (10) and the primary flywheel se (13) includes an externally positioned ring gear (21) and local zones (27, 28) for balancing measures.

Description

The invention relates to a dual-mass flywheel, used in a drive train of an internal combustion engine-powered motor vehicle, consisting of a primary part and a secondary part, which are connected via a spring damping device and can be rotated around an axis of rotation and to a limited extent relative to one another, with arc springs inserted in a spring channel of the spring damping device on the outside via a sliding shell guided and supported on a stop of the primary part and a support flange of the secondary part and the multi-part primary part includes a disk-like, axially elastic flexplate that is attached radially on the inside to the internal combustion engine and radially on the outside connected to a primary flywheel.

The previously described dual-mass flywheels constructed as dual-mass flywheels (DMF) are from the prior art such as, for example, from FIG DE 10 2012 220 519 A1 known. The dual mass flywheel is used to absorb and / or dampen torsional vibrations in drive trains of internal combustion engine-driven motor vehicles. The masses of the primary part and the secondary part can be rotated relative to one another against arc spring forces of a spring damping device, with vibrations caused by the uneven drive torque of the internal combustion engine being eliminated. The torsional vibration damper is arranged in the drive train of a motor vehicle, for example, between the crankshaft of an internal combustion engine and a vehicle clutch upstream of the gearbox.

With a direct, rigid attachment of the primary part to the crankshaft of the internal combustion engine, its movements or vibrations are transmitted to the dual-mass flywheel, which leads to flexural vibrations and / or wobbling movements of the primary part, combined with high material stress and undesirable, disruptive noise development. To avoid the aforementioned problems, the DE 103 03 561 A1 a flywheel which is attached to a crankshaft of the internal combustion engine in connection with a disk element made of flexible sheet metal. On the outer circumference, the disk element is connected to an annular flywheel. From the DE 10 2010 018 942 A1 a dual-mass flywheel is known in which the primary part is attached to the crankshaft by means of an axially flexible disk part, a so-called flexplate, in order to protect the dual-mass flywheel from deformation vibrations or axial vibrations of the crankshaft.

Furthermore, there is a need to balance the dual mass flywheel in order to improve the vibration behavior of the drive train and thus the smoothness of the motor vehicle. This is from the DE 10 2018 102 373 A1 a method for balancing is known in which the production process of the dual mass flywheel includes a balancing station in which the current imbalance of the dual mass flywheel is checked and balancing takes place if this should be necessary.

The invention is based on the object of providing a structurally and functionally improved primary part for a dual mass flywheel, the assembly and balancing of which is simplified, in order to implement a cost-effective series construction.

According to the invention, this object is achieved by a dual mass flywheel including the features of claim 1. Further preferred embodiments or developments of the invention can be found in the subclaims, the description and the associated figures.

The invention provides a one-piece flexplate for the primary part, the outer angled leg of which is enclosed by a cylindrical section of the primary flywheel for non-positive and / or cohesive positioning of the flexplate and the primary flywheel provides a ring gear and at least one zone on the outside in which measures for balancing the Dual mass flywheel can be made.

The measure according to the invention fulfills the design goal of achieving an effective flexplate connection to the primary flywheel. Furthermore, the design concept ensures that a structurally and functionally improved primary part is provided, the individual parts of which, such as flexplate, primary flywheel and toothed ring, can advantageously be assembled easily and inexpensively. The torsionally stiff, axially flexible, one-piece or single-layer flexplate effectively protects the dual-mass flywheel from axial vibrations that are triggered by the internal combustion engine, which cause comfort-restricting noises and vibrations in the drive train. The invention further comprises measures which simplify balancing of the dual mass flywheel in order to improve the vibration damping. The invention also enables both a component-optimized and a space-optimized primary part to be implemented. With the structural concept according to the invention, which includes a one-piece flexplate, a functional integration of the primary part can advantageously be achieved, combined with a weight optimization that has a positive effect on the weight of the entire dual mass flywheel affects. The dual-mass flywheel equipped with the primary part according to the invention can preferably be used in a drive train of a motor vehicle which is intended for a hybrid application. In addition, it is advisable to provide the dual mass flywheel for a drive train in which this is combined with a double clutch.

According to an advantageous embodiment of the invention, it is provided that the one-piece flexplate is fixed in the cylindrical section of the primary flywheel via an interference fit. To create a permanent fixation, a length is provided for the interference fit which corresponds to at least half the diameter of the spring channel of the spring damping device intended for the arc springs. As a supplementary measure, after the pressing in for positional positioning of the flexplate, an area of the primary flywheel can be caulked locally to create a bead.

In the event that material has to be removed from the primary centrifugal mass in a targeted manner as a result of a balancing process, this can be done by means of at least one blind hole, also called a balancing hole. For this purpose, the primary flywheel has a local zone on the outside in the cylindrical section, axially offset from the toothed ring. As an alternative or in addition to this, a vertical / vertical section of the primary flywheel offers the possibility of making a blind hole in a zone that corresponds to the central axis of the arc springs. If an additional mass, also called a balancing weight, is required due to a balancing that has been carried out, this can be attached in one of the aforementioned zones of the primary centrifugal mass. For this purpose, the additional mass made from a metallic material is preferably attached to the primary flywheel mass with a material fit or alternatively by means of balancing rivets or another balancing element.

According to the invention, the ring gear of the primary part is permanently fixed in position on the cylindrical section of the primary flywheel via an interference fit, also called an interference fit. First the ring gear seat in the primary flywheel is pulled. Then the ring gear is heated and pulled on. The shoulder is there to secure the ring gear axially when the pinion meshes during operation. The reshaped material forms a bead that also acts as an axial limit for the ring gear. On the side facing away from the bead, the ring gear can, if necessary, be secured axially by local, radially aligned caulking between the primary flywheel and ring gear.

The invention also includes an integral fastening of the ring gear on the primary flywheel. Gas-shielded welding is suitable for this, preferably metal active gas welding (MAG), the gases of which cause the desired chemical reactions. Alternatively, the ring gear can be fastened by means of laser welding.

The primary flywheel is preferably formed without cutting from an unhardened, metallic sheet steel, for which a deep-drawing process is particularly suitable. After the primary centrifugal mass has been shaped by deep drawing, continuous or local hardening of the primary centrifugal mass can be provided if necessary.

To produce the flexplate, a deep-drawing process or stamping-bending process is preferably provided, with which it can be produced cost-effectively from an unhardened steel sheet without material weakening and without additional processing or reworking. After the flexplate has been shaped from sheet steel using a non-cutting process, the component is then completely hardened. As an alternative to this, the flexplate can be manufactured without hardening from a conventional sheet steel, which is also used to manufacture primary flywheels. In order to ensure an axially flexible flexplate, it has a sheet thickness of ≥ 1.5 to ≤ 4.5 mm.

• 1: ein Ausführungsbeispiel eines erfindungsgemäßen Zweimassenschwungrades in einem Halbschnitt mit einem aufgepressten Zahnkranz;
• 2: einen Ausschnitt des Zweimassenschwungrades gemäß 1 mit einem lasergeschweißten Zahnkranz;
• 3: einen Ausschnitt des Zweimassenschwungrades gemäß 1 mit einem MAGgeschweißten Zahnkranz;
• 4: einen Ausschnitt des Zweimassenschwungrades mit einem alternativ zu 3 über eine MAG-Schweißung fixierten Zahnkranz;
• 5: einen Ausschnitt des Zweimassenschwungrades gemäß 1 mit Wuchtbohrungen in der Primärschwungmasse;
• 6: einen Ausschnitt des Zweimassenschwungrades gemäß 1 mit einer der Primärschwungmasse zugeordneten Wuchtmasse.

The invention is described in more detail below with the aid of several exemplary embodiments in six figures. However, the invention is not restricted to the exemplary embodiments shown in the figures. It shows:

• 1 : an embodiment of a dual mass flywheel according to the invention in a half section with a pressed-on toothed ring;
• 2 : a section of the dual mass flywheel according to 1 with a laser-welded ring gear;
• 3 : a section of the dual mass flywheel according to 1 with a MAG-welded ring gear;
• 4th : a section of the dual mass flywheel with an alternative to 3 Gear rim fixed by means of a MAG weld;
• 5 : a section of the dual mass flywheel according to 1 with balancing holes in the primary flywheel;
• 6th : a section of the dual mass flywheel according to 1 with a balancing mass assigned to the primary centrifugal mass.

In the 1 is a two-mass flywheel in a half-section 1 shown as a torsional vibration damper, which is intended for a drive train, not shown in detail, of a motor vehicle driven by an internal combustion engine. The dual-mass flywheel is in the installed state 1 Via the primary part, also known as the primary flywheel or input part 2 with a crankshaft 8th an internal combustion engine (not shown) connected. The primary part 2 with an abutment 3 are around a common axis of rotation 4th rotatably arranged and rotatable relative to one another. Between the primary part 2 and the abutment 3 is a spring damper 5 known structure and known mode of action effective in a spring channel 6th Arc springs distributed around the circumference as energy storage 7th includes. The bow springs are there 7th the spring damping device 5 Via stops (not shown) in an operative connection with the primary part 2 and the abutment 3 .

The multi-part primary part 2 comprises an axially elastic, one-piece flexplate 10 with a material thickness S. that have fittings 9 on the crankshaft 8th is attached. A radially outside, right-angled leg 11 the flexplate 10 is frictionally engaged in one of a cylindrical section 12th formed recording of a primary flywheel 13th pressed. The resulting interference fit 14th extends over a length L. that are at least half the diameter D. from the spring channel 6th corresponds to. In addition to the interference fit 14th it makes sense to use the components Flexplate 10 and primary flywheel 13th to connect cohesively. The spring channel 6th the spring damping device 5 is largely based on the flexplate 10 as well as one with the primary flywheel 13th connected cover element 15th limited. The bow feathers 7th are inside the spring channel 6th radially on the outside via a sliding shell 16 on the thigh 11 the flexplate 10 supported and guided.

The primary part 2 also includes a ring gear 21 one that rotates on the cylindrical section 12th the primary flywheel 13th is positioned. The also multi-part secondary part 3 includes an output hub 17th , on the outside one with the bow springs 7th operatively connected support flange 18th is attached. Furthermore, the secondary part 3 a centrifugal pendulum 19th assigned with a known structure and known mode of operation, its pendulum masses 20th on both sides of the beam flange 18th are movably arranged.

In the 2 to 6th further embodiments of the invention and their items are shown, with the 1 Identical reference numerals are used for components that match or function in the same way. The following description is largely limited to different configurations.

The 2 to 4th each show a section of the dual mass flywheel 1 , with the ring gear 21 each cohesively end on the cylindrical section 12th the primary flywheel 13th is rotatably fixed in position. According to 2 is used to attach the ring gear 21 a laser weld 22nd intended. In the 3 and 4th is the ring gear 21 by means of a MAG weld 23 , 24 rotationally fixed. In the in 3 The variant shown is the weld seam of the MAG weld 23 in one of the ring gear 21 and the section 12th the primary flywheel 13th formed hollow throat. The MAG welding 24 according to 4th includes a weld seam which is frontal in front of the section 12th the primary flywheel 13th and a protrusion of the ring gear 21 is placed.

In 5 and 6th is the ring gear 21 each with a press fit 25th torsionally rigid attached. This is done by the ring gear 21 with a radial overlap axially on the section 12th pressed, with material of the primary flywheel 13th is plastically deformed. The formed material forms a bead 26th which at the same time create an axial limit for the ring gear 21 represents. On that of the bead 26th remote side can be the ring gear 21 if necessary by one or more locally radially aligned caulking (not shown) between the primary flywheel 13th and the ring gear 21 be axially secured. Furthermore show the 5 and 6th the primary flywheel 13th assigned zones 27 , 28 in which material can be removed or added in a targeted manner as a result of a balancing process. According to 5 shows the zone 27 of the section 12th as well as the zone 28 in the cover element 15th of the section of the primary flywheel 13th in each case a blind hole shown in dashed lines 29 , 30th . In the 6th is in the zone 28 of the cover element 15th the primary flywheel 13th a balancing weight also called additional mass 31 appropriate.

List of reference symbols

1

Dual mass flywheel

2

Primary part

3

Abutment

4th

Axis of rotation

5

Spring damping device

6th

Spring channel

7th

Bow feather

8th

crankshaft

9

Screw connection

10

Flexplate

11

leg

12th

section

13th

Primary flywheel

14th

Interference fit

15th

Cover element

16

Sliding shoe

17th

Output hub

18th

Girder flange

19th

Centrifugal pendulum

20th

Pendulum mass

21

Ring gear

22nd

Laser welding

23

MAG welding

24

MAG welding

25th

Interference fit

26th

bead

27

Zone

28

Zone

29

Blind hole

30th

Blind hole

31

Balancing mass

D.

Diameter (spring channel)

L.

Length (interference fit)

S.

Material thickness (flexplate)

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• DE 102012220519 A1 [0002]
• DE 10303561 A1 [0003]
• DE 102010018942 A1 [0003]
• DE 102018102373 A1 [0004]

Claims (10)

Dual mass flywheel, used in a drive train of a motor vehicle driven by an internal combustion engine, consisting of a primary part (2) and a secondary part (3), which are connected via a spring damping device (5) and can be rotated about an axis of rotation (4) and rotated to a limited extent relative to one another The spring channel (6) of the spring damping device (5), the arc springs (7) used on the primary part (2) and a carrier flange (18) of the secondary part (3) are supported and the multi-part primary part (2) includes an axially elastic flexplate (10), which is fastened radially on the inside to the internal combustion engine and connected radially on the outside to a primary flywheel (13), characterized in that an outer angled leg (11) of the one-piece flexplate (10) is enclosed by a cylindrical section (12) of the primary flywheel (13) for the torsionally rigid attachment of the flexplate (10) and the primary flywheel (13) one positioned on the outside Includes ring gear (21) and local zones (27, 28) for balancing measures. Dual mass flywheel after Claim 1 , characterized in that the one-piece flexplate (10) is fixed in position via an interference fit (14) in the cylindrical section (12) of the primary flywheel (13), its length (L) ≥ half a diameter (D) of the spring channel (6) corresponds to. Dual mass flywheel after Claim 1 , characterized in that for balancing in the zone (27) of the cylindrical section (12) of the primary flywheel (13) at least one blind hole (29) is made on the outside. Dual-mass flywheel according to one of the preceding claims, characterized in that at least one blind hole (30) is made in the zone (28) of the cover element (15) of the primary flywheel (13) for balancing. Dual mass flywheel according to one of the preceding claims, characterized in that for balancing in the zone (27) of the cylindrical section (12) and / or the cover element (15) of the primary flywheel (13) at least one balancing mass (31), a balancing rivet or another suitable balancing element is attached or introduced. Dual mass flywheel according to one of the preceding claims, characterized in that the toothed ring (21) is positioned on the cylindrical section (12) of the primary flywheel (13) via a press fit (25). Two-mass flywheel according to one of the preceding claims, characterized in that the toothed ring (21) is firmly attached to the cylindrical section (12) of the primary flywheel (13). Dual mass flywheel according to one of the preceding claims, characterized in that the flexplate (10) is produced from a metal sheet steel by a non-cutting forming process. Dual mass flywheel after Claim 8 , characterized in that after the flexplate (10) has been shaped by the forming process, hardening of the flexplate (10) is provided. Dual mass flywheel according to one of the preceding claims, characterized in that a material thickness (S) of ≥ 1.5 mm to ≤ 2.5 mm is provided for the flexplate (10).

Images