Primary part with a flexible plate pressed integrally into the primary flywheel mass

Abstract

A dual-mass flywheel (1) is installed in the drive train of a motor vehicle driven by an internal combustion engine, and consists of a primary part (2) and a secondary part (3), the primary part and the secondary part are connected by a spring damping device (5) and can rotate about a rotation axis (4) and can be twisted relative to each other in a limited manner, an arc spring (7) installed in a spring channel (6) of the spring damping device is supported on a stop of the primary part and a support flange (18) of the secondary part, the multi-piece primary part includes a disk-like axially elastic flexible plate (10), the flexible plate is fixed to the internal combustion engine radially on the inside and is connected to the primary flywheel mass (13) radially on the outside, the outer bent leg (11) of the one-piece flexible plate is surrounded by a cylindrical section (12) of the primary flywheel mass to fix the flexible plate in a torsionally rigid manner, and the primary flywheel mass (13) includes a toothed ring (21) positioned on the outside and local areas (27, 28) for balancing measures.

Description

Technical Field

[0001] The present invention relates to a dual-mass flywheel installed in the drive system of a motor vehicle driven by an internal combustion engine, which consists of a primary part and a secondary part, which can be rotated around a rotation axis and can be twisted relative to each other in a limited manner by being connected via a spring damping device, wherein an arc spring installed in a spring channel of the spring damping device is guided on the outside by a sliding shell and supported on a stop of the primary part and a support flange of the secondary part, and the multi-piece primary part includes a disc-like, axially elastic flexible plate, which is fixed to the internal combustion engine radially on the inside and connected to the primary flywheel mass radially on the outside. Background Art

[0002] The dual mass flywheel described above, which is designed as a dual mass flywheel (ZMS), is known from the prior art (e.g. from DE 10 2012 220 519 A1). The dual mass flywheel is installed in the drive train of a motor vehicle driven by an internal combustion engine for the purpose of damping and / or damping torsional vibrations. The masses of the primary and secondary parts can be twisted relative to each other counteracting the arc spring force of the spring damper device, wherein vibrations caused by uneven drive torques of the internal combustion engine are damped. In this case, the torsional vibration damper is arranged in the drive train of the motor vehicle, for example, between the crankshaft of the internal combustion engine and the vehicle clutch located upstream of the transmission.

[0003] When the primary part is directly and rigidly fixed to the crankshaft of the internal combustion engine, its movement or vibration is transmitted to the dual mass flywheel, which leads to bending vibrations and / or shaking movements of the primary part in conjunction with high material loads and undesirable, disruptive noise development. In order to avoid these problems mentioned above, DE 103 03 561 A1 describes a flywheel that is connected to a disk element made of a flexible plate and is fixed to the crankshaft of the internal combustion engine. On the outer periphery, the disk element is connected to the annular flywheel mass. From DE 10 2010 018 942 A1, a dual mass flywheel is known in which the primary part is fixed to the crankshaft by means of a disk-like part that is flexible in the axial direction (so-called flexible plate) to protect the dual mass flywheel from deformation vibrations or axial vibrations of the crankshaft.

[0004] Furthermore, there is a need to balance a dual mass flywheel in order to improve the vibration characteristics of the drive train and thus the running smoothness of the motor vehicle. For this purpose, a method for balancing is known from DE 10 2018 102 373 A1, 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 balanced if this should be necessary. Summary of the invention

[0005] The object of the invention is to provide a structurally and functionally improved primary part for a dual mass flywheel, the assembly and balancing of which are simplified in order to enable cost-effective series construction.

[0006] According to the invention, this object is achieved by a dual mass flywheel comprising the features of the invention. Further preferred embodiments or developments of the invention emerge from the description and the associated drawings.

[0007] The present invention provides a one-piece flexible plate for a primary part, wherein the outer bent legs of the flexible plate are surrounded by a cylindrical section of the primary flywheel mass so as to position the flexible plate in a force-locked and / or material-locked manner, and the primary flywheel mass is provided with a gear ring and at least one zone on the outside in which measures for balancing the dual mass flywheel can be implemented.

[0008] The measures according to the invention achieve the following design objective: effective attachment of the flexible plate to the primary flywheel mass is achieved. In addition, the structural design ensures that a structurally and functionally improved primary part is provided, the individual parts of which (such as the flexible plate, the primary flywheel mass and the ring gear) can be assembled in an advantageously simple and cost-effective manner. The torsionally rigid, axially flexurally soft, one-piece or single-layer flexible plate effectively protects the dual mass flywheel from axial vibrations, which are triggered by the internal combustion engine and which cause noise and vibrations in the drive train that limit comfort. In addition, the invention includes measures that simplify the balancing of the dual mass flywheel in order to improve vibration damping. The invention also makes it possible to achieve a primary part that is both component-optimized and installation-space-optimized. Advantageously, the structural design according to the invention, in particular including the one-piece flexible plate, makes it possible to achieve functional integration of the primary part in conjunction with weight optimization, which has a favorable effect on the weight of the entire dual mass flywheel. Preferably, the dual mass flywheel equipped with the primary part according to the invention can be installed in the drive train of a motor vehicle intended for hybrid applications. Furthermore, it is proposed that the dual mass flywheel be provided for a drive train in which it is combined with a dual clutch.

[0009] According to an advantageous embodiment of the invention, the one-piece flexible plate is fixed in the cylindrical section of the primary flywheel mass by means of an interference fit. In order to achieve a durable fixation, the interference fit is provided with a length which corresponds at least to half the diameter of the spring channel of the spring damping device intended for the arc spring. As a supplementary measure, after the flexible plate has been pressed in to position, a region of the primary flywheel mass can be locally pressed in to achieve a projection.

[0010] In the case of a targeted removal of material from the primary flywheel mass as a result of the balancing method, this can be carried out by means of at least one blind hole drilling, also referred to as a balancing bore. For this purpose, the primary flywheel mass has a local zone on the outside in a cylindrical section that is axially offset from the ring gear. Alternatively or in addition to this, the vertical / upright section of the primary flywheel mass offers the possibility of introducing a blind hole drilling in a zone that coincides with the center axis of the arc spring. If an additional load referred to as a balancing weight is also required due to the balancing to be performed, this additional load can be installed in one of the previously mentioned zones of the primary flywheel mass. For this purpose, the additional load made of a metallic material is preferably fixed to the primary flywheel mass by material locking or alternatively by means of balancing rivets or other balancing elements.

[0011] According to the invention, the toothed ring of the primary part is permanently fixed in position on the cylindrical section of the primary flywheel mass by means of an interference fit, also known as a press fit. First, the toothed ring seat is pulled in the primary swaying plate. Next, the toothed ring is heated and pulled up. When the pinion is engaged in the operating state, the shoulder serves to fix the toothed ring axially. The modified material forms a projection, which is at the same time an axial limit for the toothed ring. On the side facing away from the projection, the toothed ring can be fixed axially if necessary by means of a local, radially oriented press fit between the primary flywheel mass and the toothed ring.

[0012] The invention also includes the material-locking fixing of the ring gear to the primary flywheel mass. Shielded gas welding, preferably metal active gas welding (MAG), is suitable for this, wherein the gas thereof causes the desired chemical reaction. Alternatively, the ring gear can be fixed by means of laser welding.

[0013] The primary flywheel mass is preferably formed from unhardened, metallic steel sheet without cutting, for which deep drawing methods are particularly suitable. After the primary flywheel mass has been formed by deep drawing, continuous or local hardening of the primary flywheel mass can be provided if necessary.

[0014] For the production of the flexible plate, a deep drawing method or a stamping and bending method is preferably provided, by means of which the flexible plate can be produced cost-effectively from unhardened steel sheet without material weakening and without additional processing or finishing. After the flexible plate made of steel sheet has been formed by a non-cutting method, the component is then completely hardened. Alternatively, the flexible plate can be produced from conventional steel sheet without hardening, which is also used for the production of primary flywheel discs. In order to ensure a flexible plate that is easily bent in the axial direction, the flexible plate has a plate thickness of ≥1.5 to ≤4.5 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Next, the invention is described in more detail based on a number of embodiments in six figures. However, the invention is not limited to the embodiments shown in the figures. It shows:

[0016] Figure 1 : An embodiment of a dual mass flywheel according to the invention in a half section with a pressed-on ring gear;

[0017] Figure 2 :according to Figure 1 A detail of a dual mass flywheel having a laser welded ring gear;

[0018] Figure 3 :according to Figure 1 A detail of a dual-mass flywheel with a MAG-welded ring gear;

[0019] Figure 4 : A section of a dual mass flywheel with Figure 3 Alternatively, the ring gear is fixed by MAG welding;

[0020] Figure 5 :according to Figure 1 A portion of a dual mass flywheel having a balancing bore in the primary flywheel mass;

[0021] Figure 6 :according to Figure 1 A portion of a dual-mass flywheel having a balancing mass associated with the primary flywheel mass. DETAILED DESCRIPTION

[0022] exist Figure 1 1 shows a dual mass flywheel 1 as a torsional vibration damper in a half section, which is intended for a drive train (not shown in greater detail) of a motor vehicle driven by an internal combustion engine. In the installed state, the dual mass flywheel 1 is connected to a crankshaft 8 of an internal combustion engine (not shown) via a primary part 2, also referred to as a primary flywheel mass or input part. The primary part 2 and the secondary part 3 are arranged to rotate about a common axis of rotation 4 and to rotate relative to each other. A spring damping device 5 of a known design and a known operating principle acts between the primary part 2 and the secondary part 3, which comprises arc springs 7 as energy storage devices, which are arranged in a circumferentially distributed manner in a spring channel 6. The arc springs 7 of the spring damping device 5 are in operative connection with the primary part 2 and the secondary part 3 via stops (not shown).

[0023] The multi-part primary part 2 comprises a one-piece flexible plate 10, which is axially elastic and has a material thickness S and is fixed to the crankshaft 8 by means of a screw connection 9. The radially outer right-angled legs 11 of the flexible plate 10 are pressed into a receiving part of the primary flywheel mass 13, which is formed by a cylindrical section 12, in a non-positive manner. The interference fit 14 that occurs here extends over a length L, which corresponds to at least half the diameter D of the spring channel 6. In addition to the interference fit 14, it is provided that the components flexible plate 10 and the primary flywheel mass 13 are connected in a materially locked manner. The spring channel 6 of the spring damping device 5 is largely delimited by the flexible plate 10 and a cover element 15 connected to the primary flywheel mass 13. The arc spring 7 is supported radially on the outside by a sliding shell 16 on the legs 11 of the flexible plate 10 inside the spring channel 6 and is guided thereon.

[0024] The primary part 2 also comprises a toothed ring 21, which is fixed in a rotationally fixed manner on the cylindrical section 12 of the primary flywheel mass 13. The secondary part 3, which is also multi-part, comprises an output hub 17, to which a support flange 18 is fixed on the outside, which is operatively connected to the arc spring 7. The secondary part 3 is also provided with a centrifugal pendulum 19 of known construction and known operating principle, the pendulum masses 20 of which are movably arranged on both sides of the support flange 18.

[0025] exist Figures 2 to 6 1 shows further embodiments according to the invention and their individual parts, wherein for Figure 1 Identical or identically acting components are provided with the same reference numerals. The following description is largely limited to the different embodiments.

[0026] Figures 2 to 4 Detailed views of a dual mass flywheel 1 are shown in each case, wherein the ring gear 21 is fixed in place in a torque-proof manner at the end face to the cylindrical section 12 of the primary flywheel mass 13 by a material connection. Figure 2 , laser welding 22 is provided to fix the ring gear 21. Figure 3 and Figure 4 In the embodiment, the ring gear 21 is torsionally fixed by means of MAG welding 23, 24. Figure 3 In the variant shown in FIG. 1 , the weld seam of the MAG weld 23 is located in the groove formed by the ring gear 21 and the section 12 of the primary flywheel mass 13 . Figure 4 The MAG weld 24 comprises a weld seam which is applied at the end face in front of the section 12 of the primary flywheel mass 13 and the projection of the ring gear 21 .

[0027] exist Figure 5 and Figure 6In the embodiment, the ring gear 21 is fixed in a torsionally rigid manner by means of a press fit 25. For this purpose, the ring gear 21 is pressed axially onto the segment 12 by means of a radial overlap, wherein the material of the primary flywheel mass 13 is plastically modified. The modified material forms a projection 26, which is simultaneously an axial limitation for the ring gear 21. On the side facing away from the projection 26, the ring gear 21 can be fixed axially by means of one or more locally radially oriented crimping portions (not shown) between the primary flywheel mass 13 and the ring gear 21, if necessary. In addition, Figure 5 and Figure 6 Regions 27 , 28 assigned to the primary flywheel mass 13 are shown, in which material can be removed or added in a targeted manner as a result of the balancing method. Figure 5 , the area 27 of the section 12 and the area 28 in the cover element 15 of the section of the primary flywheel mass 13 each show a blind hole 29, 30 drawn with a dashed line. Figure 6 In the embodiment of the invention, a balancing weight 31 , also referred to as additional mass, is installed in the region 28 of the cover element 15 of the primary flywheel mass 13 .

[0028] Reference numerals list

[0029] 1 Dual mass flywheel

[0030] 2 Primary parts

[0031] 3 Secondary parts

[0032] 4 Axis of rotation

[0033] 5 Spring damping device

[0034] 6 Spring channel

[0035] 7 Arc spring

[0036] 8 Crankshaft

[0037] 9 Bolt connection

[0038] 10 Flexible board

[0039] 11 Legs

[0040] 12 Segments

[0041] 13 Primary flywheel mass

[0042] 14 Interference joint

[0043] 15 Cover element

[0044] 16 Slide pad

[0045] 17 Driven hub

[0046] 18 Bracket flange

[0047] 19 Centrifugal Pendulum

[0048] 20 Pendulum Load

[0049] 21 Ring gear

[0050] 22 Laser welding

[0051] 23 MAG welding

[0052] 24 MAG welding

[0053] 25 Press fit

[0054] 26 Raised part

[0055] District 27

[0056] District 28

[0057] 29 Blind hole drilling

[0058] 30 Blind hole drilling

[0059] 31 Balance Quality

[0060] D Diameter (spring channel)

[0061] L Length (interference joint)

[0062] S Material thickness (flexible board)

Claims

1. A dual-mass flywheel installed in a drive train of a motor vehicle driven by an internal combustion engine, comprising a primary part (2) and a secondary part (3), which are connected via a spring damping device (5) and can rotate about an axis of rotation (4) and can rotate relative to each other in a limited manner, wherein: An arc spring (7) installed in a spring channel (6) of the spring damping device (5) is supported on the primary part (2) and on a support flange (18) of the secondary part (3), and the primary part (2) constructed in multiple parts includes an axially elastic flexible plate (10), which is fixed to the internal combustion engine radially on the inside and connected to the primary flywheel mass (13) on the outside, characterized in that the outer bent leg (11) of the one-piece flexible plate (10) is connected to the primary flywheel mass (13) by the primary flywheel mass. The cylindrical section (12) of the wheel mass (13) surrounds the flexible plate (10) to fix the flexible plate (10) in a torsionally rigid manner, and the primary flywheel mass (13) includes a toothed ring (21) positioned on the outside and local areas (27, 28) for balancing measures, and the one-piece flexible plate (10) is fixed in position in the cylindrical section (12) of the primary flywheel mass (13) by an interference fit (14), wherein the length (L) of the interference fit is ≥ half the diameter (D) of the spring channel (6).

2. The dual mass flywheel according to claim 1, characterized in that For balancing, at least one blind hole is introduced on the outside in the region of the cylindrical section (12) of the primary flywheel mass (13).

3. The dual mass flywheel according to claim 1 or 2, characterized in that For balancing purposes, at least one blind hole is introduced in the region of a cover element (15) of the primary flywheel mass (13).

4. The dual mass flywheel according to claim 1 or 2, characterized in that For balancing, at least one balancing mass (31) is installed or introduced in the region of the cylindrical section (12) of the primary flywheel mass (13) and / or in the cover element (15).

5. The dual mass flywheel according to claim 1 or 2, characterized in that: The ring gear (21) is positioned on the cylindrical section (12) of the primary flywheel mass (13) by means of a press fit.

6. The dual mass flywheel according to claim 1 or 2, characterized in that The ring gear (21) is fixed to the cylindrical section (12) of the primary flywheel mass (13) in a materially bonded manner.

7. The dual mass flywheel according to claim 1 or 2, characterized in that The flexible plate (10) is manufactured from a metal steel plate by a non-cutting forming method.

8. The dual mass flywheel according to claim 7, characterized in that After the flexible sheet metal (10) has been shaped by the shaping method, the flexible sheet metal (10) is hardened.

9. The dual mass flywheel according to claim 1 or 2, characterized in that A material thickness (S) of ≥1.5 mm to ≤2.5 mm is provided for the flexible plate (10).

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