Noise-optimized centrifugal pendulum device

Abstract

Centrifugal pendulum device (1) of a torsional vibration damper, comprising a support flange (2) rotating about an axis of rotation, to which pendulum masses (4) are assigned circumferentially distributed and movably mounted on both sides, wherein two opposing pendulum masses (4) are connected via an intermediate piece (5) arranged in a flange window (6) of the support flange (2) to form a pendulum assembly (3) in the form of a U-design, which is movably mounted via pendulum rollers (7) inserted between the support flange (2) and the intermediate piece (5), wherein a one-piece damping element (13) is integrally formed radially on the inside of the intermediate piece (5), and wherein the damping element (13) extends radially on the inside over its entire length up to the end faces orthe end-face stop lugs (23) of the intermediate piece (5), wherein rubber is provided as an elastic material for the damping element (13) and clip connections (17) designed as a puzzle-head contour are provided for attaching the damping element (13) to the intermediate piece (5), and wherein, with increasing oscillation angle, self-locking of the pendulum assembly (3) occurs by a profile (16) of the damping element (13) engaging with a stop contour (14) of the flange window (6), characterized in that the stop contour (14) has locally rounded, asymmetrically designed recesses or indentations and that the profile (16) of the damping element (13) forms radially projecting cams (15), wherein the cams (15) engage in the optimized stop contour of the flange window (6) at defined oscillation angles of the pendulum assembly (4).intervene and wherein, in a neutral position of the pendulum assembly (4) between two spaced-apart cams (15) of the damping element (13) two recesses are provided in the stop contour (14) of the flange window (6) to ensure self-locking of the pendulum assembly (3) in both directions of oscillation.

Description

[0001] The invention relates to a centrifugal pendulum device of a torsional vibration damper, comprising a support flange rotating about an axis of rotation, to which pendulum masses are assigned circumferentially distributed and movable on both sides, wherein two opposing pendulum masses are connected via an intermediate piece arranged in a flange window of the support flange to form a pendulum package in a U-design, which is each mounted to be movable by means of pendulum rollers inserted between the support flange and the intermediate piece.

[0002] In internal combustion engine-powered vehicles, the design and operation of the engine result in a non-continuous torque being transmitted from the crankshaft to the drivetrain. This causes torsional vibrations, which are damped primarily by torsional vibration dampers, often designed as dual-mass flywheels (DMFs), in conjunction with a centrifugal pendulum device (CPM). The CPM dampens or eliminates the vibrational energy by oscillating pendulum masses in the opposite direction to the vibrations to be dampened.

[0003] Such centrifugal pendulum devices are known, for example, from DE 10 2006 028 556 A1 and DE 10 2009 042 836 A1, which include several pendulum masses or pendulum packages positioned bifilarly on both sides of a support flange and movably arranged via pendulum bolts or step bolts guided in guide tracks or cam tracks.

[0004] In such centrifugal pendulum devices, undesirable noise emissions occur at low speeds, particularly during the start and stop phases, as soon as the centrifugal force acting on the pendulum masses falls below the force of gravity. The resulting lifting of the pendulum rollers or stepped bolts from their guide or cam tracks in the support flange and in the pendulum masses, and / or the chaotic impact of the pendulum rollers against the ends of the guide or cam track, leads to undesirable impact and rattling noises, the intensity of which is proportionally dependent on the kinetic energy of the pendulum masses and the pendulum rollers. This impact renders the centrifugal pendulum device ineffective, thus preventing vibration isolation. In addition to the detrimental noise generation, this impact causes increased wear, which significantly reduces the service life of the centrifugal pendulum device.

[0005] To avoid the aforementioned disturbances, DE 10 2009 042 836 A1 provides for the arrangement of elastic plastic stops on the pendulum masses. DE 10 2014 217 460 A1 discloses a centrifugal pendulum device to which a braking element is assigned. This braking element is axially displaceable against the pendulum mass via a friction lining in order to decelerate the pendulum mass as needed. The braking element can be controlled by an external device to decelerate the pendulum mass, thereby disabling the centrifugal pendulum's function.

[0006] The centrifugal pendulum device of a torsional vibration damper disclosed in DE 10 2014 112 146 A1 comprises a support flange rotating about an axis of rotation, to which pendulum masses are movably mounted and distributed circumferentially on both sides. Two axially opposed pendulum masses are connected via an intermediate piece arranged in a flange window of the support flange to form a pendulum assembly in the shape of a U-shape. The pendulum assembly is movably mounted on the support flange by means of pendulum rollers inserted between the support flange and the intermediate piece. A one-piece damping element is integrally formed on the radial inner side of each intermediate piece, extending radially along its entire length to the end or face stop lugs of the intermediate piece.

[0007] DE 11 2018 005 016 T5 discloses a centrifugal pendulum device in which pendulum masses are movably mounted on both sides of a rotating support flange about an axis of rotation. Two opposing pendulum masses are connected to each other via an intermediate piece to form a pendulum assembly. The pendulum assembly is oscillatively mounted by means of pendulum rollers inserted between the support flange and the intermediate piece. A preload element, designed as a leaf spring or double leaf spring, is arranged radially on the inside between the intermediate piece and the support flange. This leaf spring is supported radially in one direction by the support flange and in the other direction by the pendulum assembly, thus preloading the pendulum rollers radially without play. The leaf spring, referred to as the pressure element, is in constant sliding contact with a track formed in the flange window, particularly at low rotational speeds of the support flange.This sliding contact is only broken when the centrifugal forces at high speeds are greater than the preload forces of the leaf spring.

[0008] Both the centrifugal pendulum device disclosed in DE 10 2017 110 602 A1 and the US 2015 / 0 075 320 A1 can be considered the closest prior art. Disclosed therein is a centrifugal pendulum device for a torsional vibration damper, which has a support flange rotating about an axis of rotation. Pendulum masses are arranged circumferentially on both sides of the support flange and are movably mounted. Two opposing pendulum masses are axially connected via an intermediate piece to form a pendulum assembly in the shape of a U-design. The intermediate piece is movably mounted in a flange window of the support flange by means of pendulum rollers inserted between the support flange and the intermediate piece. A one-piece elastic damping element made of rubber is integrally formed radially on the inside of each intermediate piece.Clip connections designed as puzzle-head contours are provided for attaching the damping element to the intermediate piece. As the pendulum assembly oscillates, self-locking occurs at increasing oscillation angles due to contact between the damping element and the stop contour of the flange window.

[0009] The present invention is based on the objective of providing a structurally and / or functionally improved, noise-optimized centrifugal pendulum device that can be implemented cost-effectively.

[0010] This problem is solved by means of a centrifugal pendulum device constructed according to the features of claim 1. Advantageous embodiments are specified in the dependent claims.

[0011] According to the invention, the damping element profile has radially projecting cams, and the stop contour has locally rounded, asymmetrically shaped recesses or indentations. The profile engages with the stop contour of the flange window at defined oscillation angles of the pendulum assembly. In a neutral position of the pendulum assembly, two recesses are provided in the stop contour of the flange window between two spaced-apart cams of the damping element to ensure self-locking of the pendulum assembly in both directions of oscillation.

[0012] According to the inventive design, it is ensured that, synchronously with an increasing oscillation angle of the pendulum assembly constructed in a U-design, the elastic damping element is increasingly compressed, thus achieving clamping or self-locking of the pendulum assembly.

[0013] Centrifugal pendulum devices are subject to significant excitation under certain conditions (e.g., start / stop), which causes the pendulum masses to be fully deflected and their pendulum motion to be limited by the end stops (oscillation angle cut-off). Depending on the energy input, these stops can cause disruptive noise. The invention advantageously provides a solution whereby the pendulum assembly is fixed in the region of an end position or at a maximum oscillation angle during the start and / or stop phase of the internal combustion engine, thus preventing uncontrolled lifting of the pendulum rollers, also known as rolling elements. Consequently, no structure-borne noise excitation, which would cause adverse noise generation, can occur due to the fixed position of the pendulum rollers.

[0014] The operating principle of the invention is based on a self-locking or clamping of the pendulum assembly due to the pressed-in damping element between the stop contour in the flange window of the support flange and the intermediate piece. The pendulum assembly is fixed by a special shape of the damping element and by a separate design of the largely kidney-shaped flange window in the support flange.

[0015] The functionally improved centrifugal pendulum device according to the invention is particularly suitable for centrifugal pendulum devices that include pendulum packages constructed in a so-called U-design, in which, due to the design, a large radial stroke occurs simultaneously at large oscillation angles. When applying the concept according to the invention, even in the absence of centrifugal force, for example during the start-up phase or during the coast-down phase of the internal combustion engine, there is no risk of uncontrolled lifting or chaotic impact of the pendulum rollers, associated with adverse impact and / or rattling noises.

[0016] The measure according to the invention effectively and advantageously prevents or renders inaudible impact noises during the operation of the internal combustion engine. The invention thus enables the provision of a noise-optimized centrifugal pendulum device that is also cost-effective to implement. The centrifugal pendulum device designed according to the invention is advantageously usable in a torsional vibration damper or dual-mass flywheel (DMF) intended for the drivetrain of a DHT hybrid application.

[0017] According to the invention, the damping element's profile forms radially projecting cams that, at defined oscillation angles of the pendulum assembly, engage with an optimized stop contour of the flange window. For this purpose, the stop contour has locally rounded, asymmetrically designed recesses or indentations. The interacting components are designed such that, in the last third of its maximum oscillation angle, the pendulum assembly, with its formed cam on the damping element, runs onto a chamfer of the stop contour. Advantageously, the chamfer is designed such that the cam, and consequently the damping element, is continuously compressed further with increasing oscillation angle until clamping or self-locking of the pendulum assembly is achieved.In a neutral position of the pendulum assembly, two recesses are provided in the stop contour of the flange window between the two spaced-apart cams of the damping element to ensure self-locking of the pendulum assembly in both directions of oscillation.

[0018] To release the pendulum assembly from its detent or fixed position, a corresponding restoring torque is required, which is achieved during engine start-up and normal operation at idle speed or higher. One way to achieve this is to influence the overlap, the degree of overlap, or the maximum compression, and the resulting clamping force between the cams of the damping element and the stop contour of the flange window. The overlap can be determined, for example, by selecting a specific material or hardness grade for the elastic damping element. Alternatively, the overlap can be modified by precisely shaping the geometry of the recesses or chamfers in the stop contour of the flange window. For instance, the angle of a chamfer, which directly determines the strength of the self-locking mechanism and the direction vector of the clamping force, can be altered.

[0019] A pendulum assembly is provided, the one-piece damping element of which extends radially on the inside over the entire length up to the end or front stop lugs of the intermediate piece. The damping element partially encloses both end faces of the intermediate piece, forming rounded transitions with a projection beyond the rounded stop lugs of the intermediate piece.

[0020] Another aspect of the centrifugal pendulum device constructed according to the invention provides that, in the event of an absolute maximum deflection, an end shutdown of the pendulum package, the associated intermediate piece strikes a correspondingly designed end contour in the flange window of the support flange in both directions of oscillation via a rounded stop nose.

[0021] A clip connection is provided for attaching the damping element to the intermediate piece. This connection utilizes a clip designed as a puzzle-head contour. After locking into place with a corresponding contour on the intermediate piece, the puzzle-head contour forms a positive-locking connection effective in both the circumferential and radial directions. To mount the damping element, its puzzle-head contour is pressed through a narrowed opening into a complementary recess in the intermediate piece. This recess then expands elastically, creating an undercut between the puzzle-head and the narrowed opening of the intermediate piece.

[0022] Another preferred embodiment comprises a pendulum assembly in which a surface clip is arranged between each pendulum mass and the support flange as a sliding element, preventing the pendulum masses from contacting the support flange, also referred to as the pendulum flange. Preferably, the surface clips, which form sliding elements and are connected to the pendulum masses, are made of a highly wear-resistant, friction-optimized plastic. If required, the sliding elements can be integrated into the support flange. For fastening, the sliding elements can be injection-molded, glued, clipped, or pressed onto the support flange. Alternatively, the sliding elements can be loosely arranged between the pendulum mass and the support flange.

[0023] The pendulum rollers interacting with the pendulum assembly are preferably designed as stepped bolts and are loosely inserted in the flange window between the support flange and the intermediate piece. Each pendulum roller has an axially projecting projection on both sides to form a stepped roller, which, in the installed state, engages in a kidney-shaped cam track of the pendulum masses that runs in the opposite direction to the contour of the flange window.

[0024] The invention is explained below with reference to a preferred embodiment and the accompanying figures. However, the invention is not limited to the embodiment shown. Identical components or components with the same function are identified by the same reference numerals. The figures show: Fig. 1 an embodiment of a centrifugal pendulum device constructed according to the invention in an exploded view; Fig. 2 an intermediate piece from a pendulum packet of the in Fig. 1 centrifugal pendulum shown in a 0° oscillation angle position; Fig. 3. The intermediate piece in a 30° swing angle position, in which a fixation begins; Fig. 4 the intermediate piece in a 34° swing angle position in which it is fixed; Fig. 5 the intermediate piece in the 34° oscillation angle position, provided with the resulting force vectors; and Fig. 6 the intermediate piece in a 38° oscillation angle position, which corresponds to a maximum deflection.

[0025] In the Fig. Figure 1 shows a section of a centrifugal pendulum device 1, which is associated with a torsional vibration damper (not shown), also called a dual-mass flywheel (DMF), preferably used in the drivetrain of an internal combustion engine-powered motor vehicle. The centrifugal pendulum device 1 comprises a support flange 2, also called a pendulum flange, which rotates about an axis of rotation and is associated with a component of the torsional vibration damper. The support flange 2 is designed to accommodate several pendulum assemblies 3 arranged one behind the other in the circumferential direction. Each pendulum assembly 3 consists of two identically dimensioned, spaced-apart pendulum masses 4, between which the support flange 2 is positioned. To form a pendulum assembly 3 in a U-shape, two pendulum masses 4 are rigidly connected via an intermediate piece 5, which is guided with clearance through a flange window 6 of the support flange 2.All components of the pendulum package 3 are joined together via two rivet connections 10.

[0026] The centrifugal pendulum device 1, of conventional design and known operation, enables relative movement or oscillation of the pendulum assemblies 3 relative to the support flange 2 during operation when rotational irregularity is triggered by the internal combustion engine. This relative movement is ensured by two pendulum rollers 7, also called stepped bolts, assigned to each pendulum assembly 3. These rollers are guided radially on the outside of the flange window 6 of the support flange 2 and radially on the inside of a guide track 8 of the intermediate piece 5. Axially, the pendulum rollers 7 are indirectly supported on the pendulum masses 4 via surface clips 9 designed as sliding elements and are further fitted into a kidney-shaped cam track 12 of the pendulum mass 4 via a central projection 11. The cam tracks 12, which guide the pendulum rollers 7, and the contour in the flange window 6 of the support flange 2 are curved in opposite directions.

[0027] A damping element 13 is formed radially on the inside of the intermediate piece 5, extending over its entire length. Through the interaction of the damping element 13 with a stop contour 14 in the flange window 6 of the support flange 2, self-locking or clamping of the intermediate piece 5 can be achieved when defined oscillation angles of the pendulum assembly 3 are exceeded.

[0028] The Fig. 2 to Fig. Figure 6 shows components of the centrifugal pendulum device 1 in different operating states to illustrate the self-locking between the support flange 2 and the intermediate piece 5. For a better understanding of the invention, the following is shown in the Fig. 2 to Fig. 6 the centrifugal pendulum device 1 shown without the pendulum masses 4.

[0029] In the Fig. 2 to Fig. Figure 6 shows the intermediate piece 5 in different oscillation angle positions. The damping element 13, which is molded onto the intermediate piece 5, is positively locked in position in the circumferential and radial directions by means of clip connections 17 designed as puzzle-head contours. To mount the damping element 13, puzzle heads 18 are each pressed through a narrowed opening 19 into a complementarily shaped receptacle 20 of the intermediate piece 5, which expand elastically in the installed position, thereby creating an undercut between the puzzle heads 18 and the narrowed openings 19. Fig. Figure 2 shows a neutral position of the centrifugal pendulum device 1, which the intermediate piece 5 assumes at a swing angle of 0°, in which the entire pendulum assembly 3, constructed in a U-shape, can swing freely in both directions of the arrows shown. In this position, a radial distance is established between the inwardly oriented cams 15, which are axially offset from each other and formed on a profile 16 of the damping element 13, and the stop contour 14 of the flange window 6.

[0030] In the Fig. Figure 3 shows the intermediate piece 5 in a 30° oscillation angle position, in which the cams 15 of the elastic damping element 13 meet chamfers 21 of the optimized stop contour 14, thereby initiating a fixation of the intermediate piece 5.

[0031] The Fig. 4 and Fig. Figure 5 shows the intermediate piece 5 in the 34° oscillation angle position, which corresponds to a fixed state in a stop situation without restoring torque.

[0032] Due to a radial overlap 22 between the cams 15 and the stop contour 14, which is created by compression of the elastic cam material, the intermediate piece 5 becomes self-locking or clamped. Additionally, the following are described in the Fig. 5 the force vectors are shown which result in contact zones between the pendulum rollers 7 and the intermediate piece 5 and between the support flange 2 and the damping element 13 in the 34° oscillation angle position.

[0033] The intermediate piece 5 is in the Fig.Figure 6 shows the maximum deflection, which occurs, for example, during the start-up phase of the internal combustion engine. During this final shutdown, the intermediate piece 5 is directly supported by the support flange 2 via a stop lug 23 on an end contour 24 of the flange window 6. In this position, the damping element 13 between the cams 15 is subjected to a strong and radially maximum force below the stop lug 23, resulting in energy absorption. Reference symbol list 1 Centrifugal pendulum device 2 support flange 3 Pendulum package 4 Pendulum masses 5 Intermediate piece 6 flange windows 7 pendulum rollers 8 Guide rail 9 surface clip 10 rivet connection 11 Approach 12 scenery railway 13 Damping element 14 Stop contour 15 cam 16 Profiling 17 Clip connection 18 Puzzle Head 19 Opening 20 recordings 21 Slanted 22 Coverage 23 Stop nose 24 End contour

Claims

[1] Centrifugal pendulum device (1) of a torsional vibration damper, comprising a support flange (2) rotating about an axis of rotation, to which pendulum masses (4) are assigned circumferentially distributed and movably mounted on both sides, wherein two opposing pendulum masses (4) are connected via an intermediate piece (5) arranged in a flange window (6) of the support flange (2) to form a pendulum assembly (3) in the form of a U-design, which is movably mounted via pendulum rollers (7) inserted between the support flange (2) and the intermediate piece (5), wherein a one-piece damping element (13) is integrally formed radially on the inside of the intermediate piece (5), and wherein the damping element (13) extends radially on the inside over its entire length up to the end faces orextends to the end face stop lugs (23) of the intermediate piece (5), wherein rubber is provided as an elastic material for the damping element (13) and clip connections (17) designed as a puzzle head contour are provided for attaching the damping element (13) to the intermediate piece (5), and wherein, with increasing oscillation angle, a self-locking of the pendulum assembly (3) occurs by a profile (16) of the damping element (13) engaging with a stop contour (14) of the flange window (6). characterized by, that the stop contour (14) has locally rounded, asymmetrically designed recesses or indentations and that the profiling (16) of the damping element (13) forms radially projecting cams (15), wherein the cams (15) engage or latch into the optimized stop contour of the flange window (6) at defined oscillation angles of the pendulum assembly (4) and wherein, in a neutral position of the pendulum assembly (4), two recesses are provided in the stop contour (14) of the flange window (6) between two spaced-apart cams (15) of the damping element (13) to ensure self-locking of the pendulum assembly (3) in both oscillation directions. [2] Centrifugal pendulum device (1) according to claim 1, characterized by, that a restoring moment for releasing the pendulum assembly (3) from a detent or self-locking position can be influenced by a degree of overlap (22) between the cams (15) of the damping element (13) and the stop contour (14) of the flange window (6). [3] Centrifugal pendulum device (1) according to claim 2, characterized by , that a restoring moment for releasing the pendulum package (3) from a detent or self-locking position can be influenced by an angle of a slope (21) of the stop contour (14) in the flange window (6). [4] Centrifugal pendulum device (1) according to any one of the preceding claims 1 to 3, characterized by , that the damping element (13) extends on both sides into rounded end-face zones below the stop nose (23) of the intermediate piece (5). [5] Centrifugal pendulum device (1) according to any one of the preceding claims 1 to 4, characterized by, that at maximum deflection of the pendulum package (4) the associated intermediate piece (5) strikes a correspondingly designed end contour (24) in the flange window (6) via the rounded stop nose (23). [6] Centrifugal pendulum device (1) according to any one of the preceding claims 1 to 5, characterized by , that a surface clip (9) is provided as a sliding element between the pendulum masses (4) and the support flange (2). [7] Centrifugal pendulum device (1) according to any one of the preceding claims 1 to 6, characterized by , that the pendulum rollers (7) designed as stepped bolts are arranged in the flange window (6) between the support flange (2) and the intermediate piece (5), wherein on both sides an axially projecting projection (11) of the pendulum rollers (7) engages in a cam track (12) of the pendulum masses (4).

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