DE102018125615A1 - Centrifugal pendulum - Google Patents

Abstract

A centrifugal pendulum (36) for damping rotational irregularities in a drive train of a motor vehicle is provided with a support flange (44) which can be rotated about an axis of rotation (12) and a pendulum mass (40) which can be pendulated relative to the support flange (44), in particular via aerial tramways Generation of a restoring torque directed counter to the rotational non-uniformity, the pendulum mass (40) being connected to one another via a rivet connection (42) and / or the carrier flange (44) being connected to one another by means of a rivet connection (42) flange parts for guiding the pendulum mass (40) between the flange parts, the rivet connection (42) having a countersunk area (52) pressed into an associated rivet opening (54). Due to the countersunk area (52) of the rivet connection (42) pressed into the rivet opening (54), the rivet connection (42) can withstand higher loads, so that a centrifugal force pendulum (36) with good durability is possible even when impacts occur.

Description

The invention relates to a centrifugal pendulum for damping rotational nonuniformities introduced via a drive shaft of a motor vehicle engine, with the aid of which a restoring torque which is opposite to the rotational nonuniformity can be generated.

For example, from DE 10 2008 059 297 A1 a centrifugal force pendulum is known in which a pendulum mass which can be displaced relative to a carrier flange by means of rollers which are guided in corresponding raceways is provided and which can produce a restoring torque opposed to the speed fluctuation in order to dampen the speed fluctuation when the speed fluctuates. The carrier flange has two flange parts connected to one another via spacer bolts, between which the pendulum mass can oscillate and can strike when a maximum oscillation angle is reached.

There is a constant need to increase the durability of centrifugal pendulums.

It is the object of the invention to show measures which enable a centrifugal pendulum with good durability.

The object is achieved according to the invention by a centrifugal pendulum with the features of claim 1. Preferred embodiments of the invention are specified in the subclaims and the following description, which can each represent an aspect of the invention individually or in combination.

According to the invention, a centrifugal pendulum for damping rotational irregularities in a drive train of a motor vehicle is provided with a support flange that can be rotated about an axis of rotation and a pendulum mass that can be pivoted relative to the carrier flange, in particular via pendulum tracks, to generate a restoring torque that is opposite to the rotational irregularity, the pendulum mass being connected to one another via a riveted connection has connected partial masses and / or the carrier flange via a rivet connection with flange parts connected to one another for guiding the pendulum mass between the flange parts, the rivet connection in particular having a countersunk area pressed into an associated rivet opening.

For example, in the event of a sudden torque impact ("impact") in a drive train of a motor vehicle, for example when starting a bang or an interconnection, the pendulum mass of the centrifugal pendulum coupled to the drive train can deflect particularly strongly along its pendulum path and hit hard at the end of its oscillation angle. This striking of the pendulum mass when it reaches its maximum swing angle leads to mechanical loads in the components of the centrifugal pendulum. It has been recognized that a component failure of a centrifugal force pendulum can occur as a result of the failure of a rivet connection as a result of the forces occurring during an impact, in particular shear forces, which can lead to shearing off of a rivet head of the rivet connection. In the case of a rivet connection, a rivet shank of a rivet is inserted into the rivet openings of the components to be riveted together. In this case, a clearance fit is provided between the rivet shaft and the rivet openings in order to make it easy to insert the rivet shaft into the rivet openings. However, this clearance adjustment leads to an incomplete filling of the hole reveal of the rivet openings. In addition, there is a sharp-edged notch between the rivet heads and the rivet shank. It is assumed that the mechanical loads that occur when the pendulum mass strikes due to the partial filling of the hole reveal and the notch effects between the rivet heads and the rivet shaft lead to a particularly unfavorable load case at the transition of the rivet heads to the rivet shaft, which leads to mechanical failure leads the rivet connection by shearing off at least one of the rivet heads.

Due to the countersunk area of the rivet connection that is pressed into the rivet opening and countersunk in the rivet opening, an interference fit of the rivet connection can be provided in the rivet opening at least in an axially limited axial area. The lowering area can be easily pressed into the rivet opening during the production of the rivet connection by the axial forces acting during the production of the closing head. The rivet opening is preferably countersunk in order to facilitate the pressing in of the countersunk area. However, it is also possible for the material surrounding the rivet opening to be unprocessed and therefore not deformed and / or countersunk by stamping, as a result of which an additional manufacturing step is avoided. At least in a part of the axial area of the rivet connection that is occupied by the countersunk area, an essentially complete filling of the hole reveal of the rivet opening can be ensured by the rivet connection. At least in the countersunk area of the rivet connection, the surface pressure which occurs when the pendulum mass is hard struck in the transverse direction of the rivet connection can be distributed over the entire diameter of the rivet opening. In comparison to a clearance fit between the rivet shaft and the rivet opening, the forces acting in the countersunk area can be distributed over a larger cross-sectional area of the rivet connection, as a result of which pressure peaks acting on the rivet connection can be reduced. Due to the lower maximum pressure, the risk of component failure can Rivet connection can be at least reduced by shearing. In addition, it is possible to reduce or even avoid notch effects via the positioning and the axial length of the countersink area, so that the component strength of the rivet connection is further improved. Due to the lowering area of the rivet connection pressed into the rivet opening, the rivet connection can withstand higher loads, so that a centrifugal force pendulum with good durability is possible even in the event of an impact.

Under the influence of centrifugal force, the at least one pendulum mass of the centrifugal force pendulum tends to assume a position as far as possible from the center of rotation. The “zero position” is therefore the position radially farthest from the center of rotation, which the pendulum mass can assume in the radially outer position. At a constant drive speed and constant drive torque, the pendulum mass will assume this radially outer position. In the event of speed fluctuations, the pendulum mass deflects along its aerial tramway due to its inertia. The pendulum mass can be shifted towards the center of rotation. The centrifugal force acting on the pendulum mass is divided into a component tangential and another component normal to the aerial tramway. The tangential force component provides the restoring force that the pendulum mass wants to bring back to its “zero position”, while the normal force component acts on a force introduction element that initiates the speed fluctuations, in particular a flywheel connected to the drive shaft of the motor vehicle engine, and generates a counter torque there that causes the speed fluctuation counteracts and dampens the initiated fluctuations in speed. In the event of particularly strong speed fluctuations, the pendulum mass can have swung out to a maximum and assume the position lying radially innermost. For this purpose, the tracks provided in the carrier flange and / or in the pendulum mass have suitable curvatures in which a coupling element, in particular designed as a roller, can be guided. At least two rollers are preferably provided, each of which is guided on a raceway of the carrier flange and a pendulum path of the pendulum mass. In particular, more than one pendulum mass is provided. A plurality of pendulum masses are preferably distributed uniformly on the carrier flange in the circumferential direction. The inertial mass of the pendulum mass and / or the relative movement of the pendulum mass to the carrier flange is designed, in particular, to dampen a specific frequency range of rotational irregularities, in particular an engine order of the motor vehicle engine. In particular, more than one pendulum mass and / or more than one carrier flange is provided. For example, two pendulum masses connected to one another via bolts or rivets, in particular designed as spacer bolts, between which the support flange is positioned in the axial direction of the torsional vibration damper. Alternatively, two, in particular essentially Y-shaped, flange parts of the support flange can be provided, between which the pendulum mass is positioned.

If the pendulum mass is composed of a plurality of partial masses arranged one behind the other in a common circumferential area in the axial direction, these partial masses can be connected to one another with the aid of the rivet connection having the countersunk area. This can prevent the pendulum mass from falling apart due to component failure of the rivet connection. It is also possible for the partial masses to be provided spaced apart from one another, so that the carrier flange can be provided between the partial masses in the axial direction. In this case, the rivet shaft of the rivet connection can be designed as a stepped bolt and / or a spacer, for example a tubular one, is riveted from the rivet connection between the axially spaced partial masses. In addition, a stop bolt can be riveted to the support flange, for which the rivet connection having the countersunk area is additionally or alternatively used. The pendulum mass can strike the stop bolt when it reaches its maximum oscillation angle limited by the stop bolt, so that, for example, unnecessary loading of rollers guided in webs at the end of the webs is avoided. In particular, if the carrier flange has two flange parts which are spaced apart from one another in the axial direction and between which the pendulum mass is guided such that it can oscillate, the stop bolt can connect the two flange parts to one another at a defined axial distance. In this case, the rivet shaft of the rivet connection forming the stop bolt can be designed as a stepped bolt and / or a, for example tubular, spacer is riveted from the rivet connection between the axially spaced partial masses.

In particular, a setting head of the rivet connection is designed as a lens head or a cone head. A rivet, in which the rivet shaft is provided with a pan head or tapered head, already has a countersink area as a standardized standard component, which is designed as a tapered or rounded transition from the setting head to the rivet shaft connected in one piece to the setting head. This makes it possible to avoid an individually shaped rivet connection and to use an inexpensive standard component. If an intended axial force is impressed with a tool for producing the closing head when producing the rivet connection, this axial force can reduce the lowering area of the Automatically pull the setting head into the rivet opening until the setting head lies flat. This prevents the setting head from shearing off when the finished riveted joint is subjected to heavy loads.

A closing head of the rivet connection is preferably designed as a lens head or a cone head. In addition or as an alternative to the countersunk area provided on the setting head, it is possible to provide the countersunk area on the side of the closing head. If the closing head is to be formed by plastic shaping of the free end of the rivet shaft, it is possible to provide the countersunk area as a thickening of the diameter of the rivet shaft from the beginning. However, it is also possible to press part of the formed material of the rivet shank provided for forming the closing head into the rivet opening by means of a suitable forming technique and thereby to form the lowering area of the closing head. For example, the rivet shaft can be compressed within the rivet opening when the rivet connection is created, so that the perforated reveal of the rivet opening is filled more or even completely by the rivet shaft that is compressed by plastic deformation. This prevents the closing head from shearing off when the finished rivet connection is subjected to heavy loads.

The countersunk area is particularly preferably formed by a setting head and an adjoining rivet shaft and / or by a closing head of the rivet connection. As a result, the lowering area can directly adjoin the setting head and / or the closing head. This significantly reduces a notch effect. In addition, a major part of the rivet shaft can be easily inserted into the rivet openings with a clearance fit before the closing head is generated. If the countersunk area of the setting head strikes axially against the material delimiting the respective rivet opening, only a slight axial relative movement corresponding to the axial extent of the countersunk area is required to the respective rivet opening in order to produce the permanent rivet connection. This axial relative movement, in which the respective lowering area is pressed into the rivet opening, can easily take place automatically at the same time during the riveting process that produces the rivet connection, so that the production speed and the assembly are not impaired.

In particular, the countersunk area is shaped as a radius transition or truncated cone area. As a result, notch effects that impair strength can be reduced. A sharp-edged transition from the lowering area to an axially following part is avoided.

The carrier flange is preferably connected via a further rivet connection to an output element, in particular an output hub, for introducing the restoring torque into a drive train of a motor vehicle, the further rivet connection having a countersunk area pressed into an associated further rivet opening of the output element. The further rivet connection can be designed and developed in particular, as explained above with reference to the rivet connection. As a result, the strength of the connection of the centrifugal pendulum can also be increased and / or the further rivet connection can be made smaller. A component failure of the connection of the centrifugal force pendulum with the output element causing the coupling to the drive train, in particular in the case of an impact, can thereby be avoided, whereby the durability is further increased.

The invention further relates to a torsional vibration damper for torsional vibration damping in a drive train of a motor vehicle, having a primary mass for introducing a torque, a secondary mass which is designed to be limitedly rotatable relative to the primary mass via an energy storage element, in particular designed as an arc spring, for diverting a torque and a centrifugal pendulum connected to the secondary mass. which can be designed and developed as described above, in order to provide a restoring torque counter to a rotational non-uniformity. Due to the lowering area of the at least one rivet connection of the centrifugal force pendulum, which is pressed into the rivet opening, the rivet connection of the centrifugal force pendulum can withstand higher loads, so that a torsional vibration damper with good durability is possible even in the event of an impact.

The primary mass and the secondary mass, which is limitedly rotatably coupled to the primary mass via the energy storage element designed as an arc spring, can form a mass-spring system which can dampen rotational irregularities in the speed and torque of the drive power generated by a motor vehicle engine in a certain frequency range. Here, the mass moment of inertia of the primary mass and / or the secondary mass and the spring characteristic of the energy storage element can be selected such that vibrations in the frequency range of the dominant engine orders of the motor vehicle engine can be damped. The moment of inertia of the primary mass and / or the secondary mass can be influenced in particular by an additional mass attached. The primary mass can have a disc, to which a cover can be connected, as a result of which an essentially annular receiving space for the energy storage element can be limited. The primary mass can be tangential to the energy storage element, for example, by means of protrusions projecting into the receiving space attacks. An output flange of the secondary mass can protrude into the receiving space and can strike tangentially at the opposite end of the energy storage element. If the torsional vibration damper is part of a dual-mass flywheel, the primary mass can have a flywheel that can be coupled to a drive shaft of a motor vehicle engine. If the torsional vibration damper as a pulley decoupler is part of a pulley arrangement for driving auxiliary units of a motor vehicle with the aid of a traction means, the primary mass can form a pulley, on the radially outer lateral surface of which the traction means, in particular a V-belt, can engage for torque transmission. If the torsional vibration damper is used as a disk damper, in particular a clutch disk of a friction clutch, the primary mass can be coupled to a disk area carrying friction linings, while the secondary mass can be coupled to a transmission input shaft of a motor vehicle transmission.

The secondary mass particularly preferably has an output flange that can be tangentially attached to the energy storage element, the output flange forming the support flange of the centrifugal force pendulum. The number of components and the manufacturing costs can be kept low. The good strength of the rivet connection of the centrifugal pendulum means that there is no fear of component failure of the output flange, so that there is no fear of an interruption in the torque flow via the torsional vibration damper.

In particular, the primary mass forms a receiving space for receiving the energy storage element that runs in a ring in the circumferential direction, in particular sealed between the primary mass and the secondary mass, the centrifugal pendulum being positioned in the receiving space. Due to the good strength of the rivet connection of the centrifugal pendulum, the centrifugal pendulum is essentially maintenance-free, so that the centrifugal pendulum can be easily positioned in a space that is more difficult to reach compared to other places. Since the centrifugal pendulum does not have to be positioned in a maintenance-friendly installation space, it is possible to use free space radially within the energy storage element for the centrifugal pendulum, so that the installation space requirement of the torsional vibration damper can be correspondingly small.

An additional mass for increasing the mass moment of inertia of the secondary mass is preferably riveted to the carrier flange of the centrifugal force pendulum via a further rivet connection, the further rivet connection having a countersunk area pressed into an associated further rivet opening of the additional mass. The further rivet connection can be designed and developed in particular, as explained above with reference to the rivet connection. The additional mass increases the moment of inertia on the secondary side, so that the pendulum mass can strike particularly hard when an impact occurs. Due to the lowering area of the further rivet connection, however, there is increased strength, so that even with an additional mass with a particularly high mass moment of inertia, component failure in the further rivet connection is not to be feared.

• 1: eine schematische Schnittansicht eines Drehschwingungsdämpfers,
• 2: eine schematische Detailansicht einer ersten Ausführungsform einer Nietverbindung des Drehschwingungsdämpfers aus 1 und
• 3: eine schematische Detailansicht einer zweiten Ausführungsform einer Nietverbindung des Drehschwingungsdämpfers aus 1.

In the following, the invention is explained by way of example with reference to the accompanying drawings using preferred exemplary embodiments, the features shown below being able to represent an aspect of the invention both individually and in combination. Show it:

• 1 : a schematic sectional view of a torsional vibration damper,
• 2nd : A schematic detailed view of a first embodiment of a rivet connection of the torsional vibration damper from 1 and
• 3rd : A schematic detailed view of a second embodiment of a rivet connection of the torsional vibration damper 1 .

The in 1 torsional vibration damper shown 10th For a drive train of a motor vehicle, one has about an axis of rotation 12th rotatable primary mass 14 on, which can be screwed to a drive shaft of a motor vehicle engine. The primary mass 14 has a welded lid 16 on so the primary mass 14 a circumferential annular receiving space 18th limited in a tangential to the primary mass 14 impactable energy storage element 20th is provided. In the illustrated embodiment, the energy storage element 20th formed by two coaxial arc springs. About the energy storage element 20th is a secondary mass 22 limited twist on the primary mass 14 coupled. The secondary mass 22 has a tangent to the energy storage element 20th attachable output flange 24th on, with an output element designed as an output hub 26 connected is. The output element 26 can be splined 28 non-rotatably connected to a shaft, for example a motor shaft of an electrical machine and / or a transmission input shaft of a motor vehicle transmission. In addition there is an additional mass 30th with the output flange 24th and the output element 26 connected to the secondary moment of inertia of the secondary mass 22 to increase. In the illustrated embodiment, there is also a sealing membrane designed as a plate spring 32 with the secondary mass 22 attached with a spring force via a slide ring 34 against the lid 16 the primary mass 14 presses to the recording room 18th seal and apply a conscious friction, so with a relative rotation of the secondary mass 22 to the primary mass 14 a resonance-induced rocking of torsional vibrations can be dampened.

In the recording room there is also a centrifugal pendulum 36 provided to provide additional torsional vibration damping. In the illustrated embodiment, the centrifugal pendulum has 36 one of several sheet-like partial masses 38 compound pendulum mass 40 on. The respective partial masses 38 are about one in 2nd and 3rd Rivet connection shown in more detail 42 riveted together. The pendulum mass 40 is on a support flange 44 guided in a pendulum manner, the carrier flange in the exemplary embodiment shown 44 with the output flange 24th the secondary mass 22 coincides. The output flange 24th is with the output element 26 , the sealing membrane 32 and the additional mass 30th via another riveted joint 46 riveted, also like the one in 2nd and 3rd rivet connection shown 42 can be designed.

In the 2nd partially shown rivet connection 42 shows one with a rivet shank 48 integrally connected setting head 50 on. The setting head 50 is designed as a lens head, so that one from rivet shank 48 and setting head 50 Composite standard component a lowering area designed as a transition radius 54 has, which is directly from the rest of the setting head 50 in the rivet shaft 48 transforms. When making the riveted joint 42 can of rivet 48 with clearance fit in corresponding rivet openings 52 be inserted and during the manufacture of the closing head by the acting axial forces in the adjacent rivet opening 52 be pressed in and sunk. It is also possible that additionally or alternatively on the closing head of the rivet connection 42 the sinking area 54 is trained.

At the in 3rd partially shown embodiment of the rivet connection 42 is compared to that 2nd illustrated embodiment of the rivet connection 42 the setting head 50 designed as a cone head. A riveted one 48 and setting head 50 The assembled standard component has a countersunk area designed as a truncated cone 54 on that immediately from the rest of the setting head 50 in the rivet shaft 48 passes and in the manufacture of the rivet connection 42 into the adjacent rivet opening 52 can be pressed in and sunk.

Reference list

10th

Torsional vibration damper

12th

Axis of rotation

14

Primary mass

16

cover

18th

Recording room

20th

Energy storage element

22

Secondary mass

24th

Output flange

26

Output element

28

Splines

30th

Additional mass

32

Sealing membrane

34

Slide ring

36

Centrifugal pendulum

38

Partial mass

40

Pendulum mass

42

Riveted joint

44

Support flange

46

further rivet connection

48

Riveting

50

Setting head

52

Rivet opening

54

Lowering area

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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 102008059297 A1 [0002]

Claims (10)

Centrifugal pendulum for damping rotational irregularities in a drive train of a motor vehicle, with a support flange (44) rotatable about an axis of rotation (12) and a pendulum mass (40) which can be oscillated relative to the carrier flange (44), in particular via pendulum tracks, in order to generate a restoring torque which is counter to the rotational irregularity, wherein the pendulum mass (40) has partial masses (38) connected to one another via a rivet connection (42) and / or the carrier flange (44) has flange parts connected to one another via a rivet connection (42) for guiding the pendulum mass (40) between the flange parts. wherein the rivet connection (42) has in particular a countersunk area (52) pressed into an associated rivet opening (54). Centrifugal pendulum after Claim 1 characterized in that a setting head (50) of the rivet connection (42) is designed as a lens head or a cone head. Centrifugal pendulum after Claim 1 or 2nd characterized in that a closing head of the rivet connection (42) is designed as a lens head or cone head. Centrifugal pendulum according to one of the Claims 1 to 3rd characterized in that the countersunk area (52) is formed by a setting head (50) and an adjoining rivet shaft (48) and / or by a closing head of the rivet connection (42). Centrifugal pendulum according to one of the Claims 1 to 4th characterized in that the countersink area (52) is formed as a radius transition or truncated cone area. Centrifugal pendulum according to one of the Claims 1 to 5 characterized in that the carrier flange (44) is connected via a further rivet connection (46) to an output element (26), in particular an output hub, for introducing the restoring torque into a drive train of a motor vehicle, the further rivet connection (46) connecting one into an associated further one Has rivet opening of the output element (26) pressed-in countersunk area (52). Torsional vibration damper for damping torsional vibrations in a drive train of a motor vehicle, with a primary mass (14) for introducing a torque, a secondary mass (22) which can be rotated to a limited extent relative to the primary mass (14) and which is designed, in particular as an arc spring, for discharging a torque and a centrifugal pendulum (36) connected to the secondary mass (22) according to one of the Claims 1 to 6 to provide a restoring torque against a rotational nonuniformity. Torsional vibration damper after Claim 7 characterized in that the secondary mass (22) has an output flange (24) which can be tangentially attached to the energy storage element (20), the output flange (24) forming the carrier flange (44) of the centrifugal force pendulum (36). Torsional vibration damper after Claim 7 or 8th characterized in that the primary mass (12) forms a receiving space (18) for receiving the energy storage element (20), running in the circumferential direction in a ring-shaped manner, in particular sealed between the primary mass (14) and the secondary mass (22), the centrifugal pendulum (36) in the receiving space (18) is positioned. Torsional vibration damper according to one of the Claims 7 to 9 characterized in that an additional mass (30) for increasing the mass moment of inertia of the secondary mass (22) is riveted to the carrier flange (44) of the centrifugal pendulum (36) via a further rivet connection (46), the further rivet connection (46) fitting one into an associated one has a further rivet opening of the additional mass (30) pressed-in countersunk area (52).

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