Centrifugal pendulum with a limit switch via an intermediate piece

Abstract

Centrifugal pendulum (1) of a torque transmission device of an internal combustion engine-driven vehicle, which is used for speed-dependent torsional vibration damping and is associated with a rotating support flange (2), wherein the centrifugal pendulum (1) comprises several pendulum masses (4) distributed circumferentially on both sides of the support flange (2), wherein two opposing pendulum masses (4) are connected via an intermediate piece (7) engaging with clearance in a cutout contour (8) of the support flange (2) to form a pendulum mass package (3), wherein the pendulum masses (4) are guided via rollers (9) which are each guided on a cam track (10) of the support flange (2) and on a guide track (11) of the intermediate piece (7) running in the opposite direction thereto, and the intermediate piece (7) includes an elastic damping element (14),and wherein, after a defined deformation of the damping element (14), an end stop of the pendulum mass package (3) is effected via stop lugs (17) formed directly on the intermediate piece (7), characterized in that spacer elements (12) are assigned to both sides of the intermediate piece (7), wherein axial contact and direct contact of the pendulum masses (4) with the support flange (2) is prevented by the spacer elements (12), and in that the elastic damping element (14) is simultaneously fixed laterally via the spacer elements (12).

Description

The invention relates to a centrifugal pendulum of a torque transmission device of an internal combustion engine-driven vehicle, which is assigned to a rotating carrier flange and is used for rotational speed-dependent torsional vibration damping, the centrifugal pendulum comprising a plurality of pendulum masses which are distributed circumferentially on both sides of the carrier flange and are accommodated in a pendulum manner, wherein in each case two opposite pendulum masses are connected via an intermediate piece which engages with play in a cutout contour of the carrier flange, according to the features of the preamble of claim 1.Centrifugal pendulums are used for vibration damping, in particular for isolation of torsional vibrations in drive trains of motor vehicles, which are driven by means of an internal combustion engine. In this case, the vibration energy or the vibration amplitude is damped or attenuated in that pendulum masses of the centrifugal pendulum arrangement oscillate in the opposite direction to the oscillations to be damped.DE 10 2006 028 556 A1 discloses a centrifugal pendulum for rotational speed-dependent torsional vibration damping, which includes a plurality of pendulum masses and at least one central carrier flange designed in the form of a circular ring disk. On the flanks of the carrier flange, a pendulum mass is movably guided via rollers. For this purpose, the rollers are inserted in slide blocks or guides running in opposite directions to one another in the carrier flange and in the pendulum masses. The pendulum masses arranged on both sides of the carrier flange are connected by bolts which are guided in the carrier flange with play. As a measure for damping an impact when the end position of the pendulum masses is reached, the bolts are sheathed with a plastic material.DE 10 2014 110 233 A1 shows a centrifugal pendulum having a pendulum mass package of multi-part construction. The pendulum mass packages arranged spaced apart in the circumferential direction each consist of pendulum masses movably positioned on both sides on the carrier flange. In this case, the pendulum masses are joined together via an intermediate piece engaging with play in a cutout contour of the carrier flange. The pendulum mass package is guided with the aid of rollers which are introduced into slide blocks or guides of the pendulum masses and of the carrier flange running in opposite directions to one another.DE 10 2014 112 392 A1 discloses a centrifugal pendulum according to the features of the preamble of claim 1, For the centrifugal pendulum constructed according to the invention, provision is made in which, after a defined deformation of an elastic damping element designated as a stop damping element, the pendulum mass package is shut off in each vibration direction via stop lugs formed directly on the intermediate piece.The object of the invention is to provide a centrifugal pendulum with functionally improved overload protection by means of a simple and cost-effective measure.The problem mentioned above is solved by a centrifugal pendulum including the features of claim 1. The claims dependent on claim 1 represent advantageous embodiments of the subject matter according to the invention.According to the invention, as a measure for achieving a defined installation position of the pendulum masses with respect to the carrier flange, a spacer element designed in the manner of a disk is assigned to both sides of the intermediate piece. Due to the material thickness of the spacer element, an axial distance or an axial installation clearance between the carrier flange and the pendulum masses can be set or influenced. The spacer elements prevent axial run-up and direct contact of the pendulum masses on the carrier flange, whereby the friction and thus the efficiency of the centrifugal pendulum is improved. Via the spacer element directly assigned to the intermediate piece and radially protruding at least locally or in regions, the elastic damping element is simultaneously laterally fixed. Preferably, a wear-resistant, heat-resistant plastic such as HNBR polymer is provided as material for the elastic damping element.The stop lugs are designed in such a way that the end deactivation only occurs after the damping element has been compressed in a defined manner in order to dissipate excess energy.During the final deactivation, the intermediate piece of the pendulum mass package makes tangential contact, via a stop region of the stop lugs, with a contact zone in the cut-out contour of the carrier flange in each direction of vibration. Advantageously, a reliable and wear-free oscillation angle limitation can be realized by means of a corresponding shaping of the stop lugs and the contact zones, combined with an effective deactivation and a desired functionally improved overload protection of the centrifugal pendulum.With the centrifugal pendulum constructed according to the invention, a two-stage deactivation of the centrifugal pendulum occurs in the case of large excitations extending over the entire oscillation angle of the pendulum mass stack, for example in the start and stop phases of the internal combustion engine. First, energy is dissipated by limited elastic deformation of the damping element before a stop nose reaches the contact zone in the cut-out contour of the carrier flange, whereby the oscillation angle is ended and the centrifugal pendulum is shut off. By means of this measure which mechanically shuts off the centrifugal pendulum, the elastic damping element is protected from further compression and thus from overloading and premature failure.A preferred embodiment of the invention comprises a metallic intermediate piece connecting the pendulum masses, the end-side, integrally formed stop lugs of which are each aligned in the vibration plane of the pendulum mass stack. By configuring the stop lugs, the centrifugal pendulum can be switched off, for example, at a vibration angle of 50°, also referred to as a block angle. A reliable mode of operation of the centrifugal pendulum is achieved in that a steel / steel contact is established between the cut-out contour in the carrier flange and the stop lugs at a maximum oscillation angle of the pendulum masses of the pendulum mass stack.The pendulum mass package of the centrifugal pendulum according to the invention is preferably U-shaped, the parallel spaced pendulum masses of which are guided laterally on the carrier flange. Furthermore, the pendulum masses are connected to form a structural unit via the intermediate piece which engages into the cut-out contour of the carrier element and forms a coupling element.Furthermore, the pendulum mass package includes an elastically deformable damping element which extends over an underside of the intermediate piece and is fixed in position on the intermediate piece by means of integrally formed knobs or retaining clips. For this purpose, knobs which are arranged offset with respect to one another engage positively in corresponding openings of the intermediate piece.The spacer elements arranged laterally on the intermediate piece and embodied in the manner of disks are made of a metallic material, for example a steel sheet or of a durable, wear-resistant plastic.All individual parts of the pendulum mass package, the intermediate piece, the outer spacer elements and the pendulum masses are preferably combined by means of rivets to form a structural unit. Alternatively, it is possible to connect all components to one another in a materially integral manner to form a structural unit.The invention is described in more detail below with reference to an exemplary embodiment depicted in two figures. However, the invention is not limited to the embodiment shown in the figures. It shows: FIG. 1 : a section of a centrifugal pendulum, wherein the position of the pendulum masses corresponds to an oscillation angle of 0°; FIG. 2 : the illustration according to FIG. 1, wherein the position of pendulum masses corresponds to an angle of oscillation of 50°.FIG. 1 and FIG. 2 each show, in a partial view, the basic structure of a rotatable centrifugal pendulum 1, which is assigned to a drive train of an internal combustion engine-driven motor vehicle of a torque transmission device (not shown), also called ZMS. The centrifugal pendulum 1 comprises a carrier flange 2 which rotates about an axis of rotation (not shown) and is associated with a shaft of the drive train and is intended to receive a plurality of pendulum mass packages 3 arranged one behind the other in the circumferential direction. Each pendulum mass package 3 comprises two identically dimensioned pendulum masses 4 positioned on both sides of the carrier flange 2, which are connected by stepped bolts 5. Each stepped bolt 5, also called a spacer rivet or coupling element, is guided with great play in a guide slot 6 by the carrier flange 2 and at the same time fixed in position in the pendulum masses 4 in a rotationally fixed manner. To clarify the structure and the arrangement, the pendulum mass package 3 is depicted in both figures without the front pendulum mass 4. Both pendulum masses 4 of pendulum mass package 3 are furthermore rigidly connected via an intermediate piece 7, which engages with sufficient play in a cut-out contour 8 of carrier flange 2 and enables an unhindered oscillation or adjusting movement of pendulum mass package 3. The intermediate piece 7 and the pendulum masses 4 guided laterally on the carrier flange 2 form a U-shaped pendulum mass package 3.Spacer elements 12 are provided on both sides of the intermediate piece 7 which are fastened by rivets 13 and are designed, for example, as spacer plates. The rivets 13 also join together the pendulum masses 4 of the pendulum mass stack 3 to form a structural unit. The intermediate piece 7 comprises, on a side facing away from a link track 10 of the carrier flange 2, a damping element 14 which extends over the entire underside and is produced from an elastic plastic. The damping element 14 is fastened, as shown in FIG. 2, by means of integrally formed knobs 15 which engage positively in corresponding openings 16 of the intermediate piece 7. A lateral fixing of the damping element 14 is effected by the lateral spacer elements 12 extending radially over the outer contour of the intermediate piece 7.The centrifugal pendulum 1 with a conventional design and known mode of operation enables a relative movement of the pendulum mass package 3 with respect to the carrier flange 2 in the operating state in the event of a rotational non-uniformity occurring. For this purpose, the pendulum masses 4 are movably guided via two rollers 9 spaced apart from one another, also referred to as rolling bodies, which are each guided on the link track 10 of the carrier flange 2 and on a guide track 11 of the intermediate piece 7 running in opposite directions thereto. Furthermore, in order to secure the position of the rollers 9, in particular in the stop phase of the centrifugal pendulum 1, each roller 9 is guided on both sides via axially protruding projections 19 in securing tracks 20 of the pendulum masses 4. On the intermediate piece 7 of the centrifugal pendulum 1 constructed according to the invention, stop noses 17 aligned in the vibration planes are formed on both ends or end faces. A final deactivation of the centrifugal pendulum 1 takes place as soon as a stop nose 17, as shown in FIG. 2, is supported on a contact zone 18 in the region of the cut-out contour 8 of the carrier flange 2. Due to the protruding damping element 14, the final deactivation takes place only after a defined compression of the damping element 14.FIG. 1 shows the pendulum mass package 3 under centrifugal force in a position which corresponds to an oscillation angle of 0° with respect to the carrier flange 2. The intermediate piece 7 is supported or guided by the carrier flange 2 via the rollers 9 directly on the slide track 10.FIG. 2 shows the centrifugal pendulum 1, the pendulum mass package 3 of which is positioned at a maximum oscillation angle, also called a block angle, of 50° relative to the carrier flange 2. In this position, a final shutdown and an effective overload protection of the centrifugal pendulum 1 are established, in which a stop nose 17 is supported on the contact zone 18 of the carrier flange 2 after a limited deformation of the damping element 14.List of reference characters1 Centrifugal pendulum 2 Carrier flange 3 Pendulum mass package 4 Pendulum mass 5 Stepped bolt 6 Guide slot 7 Intermediate piece 8 Cutout contour 9 Roller 10 Slide track 11 Guide track 12 Spacer element 13 Rivet 14 Damping element 15 Knobs 16 Opening 17 Stop nose 18 Contact zone 19 Shoulder 20 Securing track

Claims

Centrifugal pendulum (1) of a torque transmission device of an internal combustion engine-driven vehicle, which is used for rotational speed-dependent torsional vibration damping and is assigned to a rotating carrier flange (2), wherein the centrifugal pendulum (1) comprises a plurality of pendulum masses (4) which are distributed circumferentially on both sides of the carrier flange (2) and are accommodated in a pendulum manner, wherein in each case two opposite pendulum masses (4) are connected via an intermediate piece (7) which engages with play in a cutout contour (8) of the carrier flange (2) in order to form a pendulum mass stack (3), wherein the pendulum masses (4) are guided via rollers (9) which are each guided on a link track (10) of the carrier flange (2) and on a guide track (11) of the intermediate piece (7) which runs in the opposite direction thereto, and the intermediate piece (7) encloses an elastic damping element (14), and wherein, after a defined deformation of the damping element (14), the pendulum mass package (3) is finally deactivated via stop noses (17) formed directly on the intermediate piece (7), characterized in that spacer elements (12) are assigned to both sides of the intermediate piece (7), wherein axial contact and direct contact of the pendulum masses (4) on the carrier flange (2) is prevented by the spacer elements (12), and in that the elastic damping element (14) is fixed laterally at the same time via the spacer elements (12).Centrifugal pendulum (1) according to Claim 1, characterized in that the stop lugs (17) are integrally formed on both ends of the metallic intermediate piece (7) and are each aligned in the direction of a vibration plane of the pendulum mass stack (3).Centrifugal pendulum (1) according to one of the preceding claims, characterized in that a steel / steel contact is established at a maximum oscillation angle between the carrier flange (2) and the stop lugs (17) of the intermediate piece (7).Centrifugal pendulum (1) according to one of the preceding claims, characterized in that the pendulum mass package (3) is of U-shaped design, the pendulum masses (4) of which, guided laterally on the carrier flange (2), are connected via the intermediate piece (7) engaging into the cutout contour (8) of the carrier element (2).Centrifugal pendulum (1) according to one of the preceding claims, characterized in that the damping element (14) extends over an underside of the intermediate piece (7) and is fixed in position by means of integrally formed knobs (15) which engage positively in corresponding openings (16) of the intermediate piece (7).Centrifugal pendulum (1) according to one of the preceding claims, characterized in that HNBR polymer is provided as material for the damping element (14).Centrifugal pendulum (1) according to one of the preceding claims, characterized in that the spacer elements (14) are produced from a metallic material or a wear-resistant plastic.Centrifugal pendulum (1) according to one of the preceding claims, characterized in that the pendulum masses (4), the intermediate piece (7) and the outer spacer elements (12) are combined by means of rivets (13) to form the pendulum mass package (3).Centrifugal pendulum (1) according to one of the preceding claims, characterized in that the pendulum masses (4), the intermediate piece (7) and the outer spacer elements (12) are combined in a materially bonded manner to form the pendulum mass package (3).

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