WO2006103004A1

WO2006103004A1 - Camshaft adjuster

Info

Publication number: WO2006103004A1
Application number: PCT/EP2006/002518
Authority: WO
Inventors: Dirk Heintzen; Rainer Ottersbach; Ahmet Deneri
Original assignee: Schaeffler Kg
Priority date: 2005-04-01
Filing date: 2006-03-20
Publication date: 2006-10-05
Also published as: DE102005014883A1

Abstract

The invention relates to a camshaft adjuster for an internal combustion engine. In said adjuster the relative angular relation between a drive gear (2) and a driven element, which is driven by means of a connection to a camshaft, can be modified by an actuating unit. According to the invention, the camshaft adjuster (1), in particular the drive gear (2) comprises a vibration damper (3). The vibration damper (3) reduces unwanted vibrations, forces and torques during the operation of the camshaft adjuster. According to one specific embodiment of the invention, the vibration damper (3) has a material connection to the assigned component of the camshaft adjuster (1).

Description

Name of the invention

Phaser

description

Field of the invention

The invention relates to a camshaft adjuster for an internal combustion engine, in which the relative angular relationship between a drive element and an output element is variable via a control unit, in particular according to the preamble of claim 1.

Background of the invention

The involved elements of a camshaft drive from a crankshaft via a camshaft adjuster to a camshaft lead during operation of an internal combustion engine u. U. to unwanted vibrations. There are different mechanisms for their causes:

An excitation due to unwanted speed fluctuations of the crankshaft.

An uneven transmission of the drive movement between the crankshaft and a drive element of the camshaft adjuster, in particular irregularities as a result of tooth engagement of a traction device in a drive wheel of the crankshaft and a drive wheel of the camshaft adjuster. For example, a toothed chain or a toothed belt is used as traction means with non-uniform tooth engagement and / or different spring and damping properties of

Traction means depending on the number of dental interventions. Vibration excitations by the operation of the camshaft adjuster, for example, as a result of the application of the steep movement, play or lots o. Ä ..

- Nonuniformities of the rotational movement of the camshaft and the associated valves, for example due to rotating masses or the opening and closing movement of the valves.

To eliminate such unwanted vibrations, it is known from document DE 197 16 411 C1 to reduce rotational irregularities due to the so-called "polygon effect" of chain drives by the use of a Radialtilgers, which cooperates with a sprocket, is tuned to the polygon frequency and has a high attenuation , so that as broadband as possible frequency suppression takes place.

From DE 103 07 336 A1 a speed-independent vibration absorber for a camshaft or crankshaft is known, can be effectively eradicated with the torsional vibrations over the entire speed range of a wave and beyond free mass forces second order can be damped.

Furthermore, so-called speed-adaptive vibration absorbers are known, which are preferably used in the area of a flywheel or the crankshaft and which have a speed-dependent and / or amplitude-dependent natural cycle frequency, whereby the eradication effect on the application and the operating conditions and over an increased frequency range improved can be. For example only reference is made to document DE 198 31 159 B4; Further publications are searchable under the search term "speed-adaptive vibration absorber".

Furthermore, the use of a damping device in the region of a belt tensioner is described from document DE 38 54 613 T3. From document DE 196 04 991 A1 a camshaft adjuster is known in which the adjusting movement is limited by end stops. To dampen vibrations due to shocks when the end stops are reached, shock isolation elements are used.

From the document DE 102 48 351 A1 an electrically driven camshaft adjuster is known in which a three-shaft gear is formed with the drive element, the output element and a motor shaft of the electric actuator. The motor shaft has a coupling which has an elastic polymer ring, which causes a vibration damped introduction of the drive torque of the actuator.

From the document DE 201 05 838 U1 a vibration damper for a camshaft or crankshaft is known, which has a torsion spring rod and a TiI- germasse, with torsion spring rod and absorber mass are arranged within the cam or crankshaft.

Object of the invention

The invention has for its object to provide a camshaft adjuster, which has improved dynamic properties in compliance with the building conditions.

Summary of the invention

According to the invention the object is solved by the features of independent claim 1. Further embodiments of the invention will become apparent from the dependent claims 2 to 10. According to the invention, the camshaft adjuster has a vibration damper. Such a vibration absorber is understood in particular to mean a degree of freedom system, a multi-degree-of-freedom system or an oscillatory continuum which is not arranged in series in the force flow of the camshaft adjuster between the drive element and the output element, but rather parallel to it. The vibration absorber according to the invention may be a vibration absorber of any design which has, for example, one or more constant frequencies or is speed-adaptive or amplitude-adaptive. In addition to an adaptation of the vibration absorber on the speed and / or amplitude of a vibration movement and an "active" adjustment of the mechanical properties of the vibration is possible. This can be done in particular via a suitable adjusting unit or via the adjusting movement of the camshaft adjuster, so that the mechanical properties of the vibration absorber are dependent on the setting angle. In the event that a hydraulic control unit is used, the adjustment of the mechanical properties of the vibration damper can also take place via the existing hydraulic control pressure.

In the event that a vibration damping in a discrete frequency range of interest, the use of a vibration absorber with a low attenuation is possible - however, a vibration damping in a wider frequency range desired, this can be supported by increasing the damping of the vibration absorber. The vibration absorber preferably has a discrete mass, for example a metallic component, which is connected via an elastic and / or damping element to the component of the camshaft adjuster. Such an element may be formed with rubber, plastic, rubber or an elastomeric body.

The vibration damper is supported against an associated component of the camshaft adjuster, which lies directly or indirectly in the aforementioned power flow. By such a support of the vibration damper coupled on the one hand with the movement of the component of the Nockenwellenversteliers. On the other hand, reaction forces resulting from the vibration damper can be fed into the camshaft adjuster via the component, such that an improved vibration response, at least in a partial region of the frequency band, from the superimposition of the forces resulting from the vibration absorber and the remaining movements and forces of the camshaft adjuster. give an improved frequency spectrum and smoother running of the camshaft adjuster.

A tuning of the vibration damper is done by design specification, when commissioning the camshaft adjustment or by adaptation during operation. An adaptation can be made as a function of the application of the camshaft adjusting, in accordance with the expected speeds of the camshaft Verstellelier and in dependence of the components of the internal combustion engine involved, for example, depending on the expected Dreun- unguniformities of the spherical wave, of polygon effects of a sprocket, rotational irregularities caused by the traction means are caused by the Nockenwellentriebs, rotational nonuniformities due to the camshaft adjustment itself or vibration excitations, which have their cause in the rotational movement of the camshaft and / or the adjusting movement of the valves.

The embodiment of the invention can allow in a particularly simple manner that camshaft adjuster optionally be equipped with a vibration absorber, since the power flow of the camshaft adjusting per se is not affected by the vibration damper, since the vibration damper is not turned on in the power flow, but is connected in parallel thereto. As a result, the diversity of an offered camshaft adjusting device can be increased in a particularly simple manner.

If a camshaft adjuster (in addition or subsequently) to be equipped with a vibration absorber, so this vibration absorber can be separately, u. U. by a supplier, are manufactured and then connected to the camshaft adjuster on the component. Another advantage is the location of the arrangement of the vibration damper, since this is the camshaft upstream and thus keeps the introduction of any vibrations of the drive member of the camshaft. Another advantage may be the use of a vibration damper in the region of the camshaft adjuster instead of in the region of the crankshaft, since the camshaft and thus the camshaft adjuster rotates at half the speed of the crankshaft.

The vibration absorber can be connected in a variety of ways to the associated component of the camshaft adjuster, for example via a fastening means such as a screw or positively. According to another proposal of the invention, however, the vibration absorber is firmly bonded to the camshaft adjuster. This embodiment can lead to the following advantages:

Such a cohesive connection requires a particularly small space requirement for the connection.

- Furthermore, the cohesive connection can be provided in a particularly cost-effective manner, for example by means of an adhesive or by an elastic element of the vibration damper is vulcanized directly on the associated component of the camshaft adjuster.

Furthermore, a cohesive connection is a very reliable connection.

In contrast to a use of a screw connection via a material connection also has a very low weight, so that the moment of inertia of the camshaft adjuster is kept low. Furthermore, the use of a cohesive connection also allows relative to a screw changed degrees of freedom of the elastic element: for example, the elastic element connected by oriented in the axial direction of the camshaft adjuster screws with the associated component, the screw is a fixed point of the elastic member, from which elastic deformations can be brought about only by intermediate material regions of the elastic element in the circumferential direction or upstream regions in the axial direction.

While a dimension is specified by fasteners such as screw through the length of the screw, which is useless for the vibration damper, a cohesive connection of the vibration can be done almost without the necessary space for the connection fertilize itself.

Furthermore, fasteners require suitable mating surfaces on the associated component of the camshaft adjuster, such as holes for a screw connection, which mean increased manufacturing costs for the associated component of the camshaft adjuster. In contrast, a cohesive connection with an arbitrarily designed assigned component of the camshaft adjuster can take place.

On the other hand, the use of a fastener such as a screw connection also requires a passage or connection of the fastener with the elastic member, which u. U. may mean a weakening of the elastic element. Such a weakening does not occur for a cohesive connection of the vibration absorber.

The configuration according to the invention can lead to better maintenance of required round runs, because in the tolerance chain an adapted screwed part such as mass and intermediate body with associated shape and position tolerances is not present.

Preferably, the vibration damper is a rotation damper. Such a rotation damper can be coupled in a particularly simple manner with the rotary drive movement and any undesired dynamic states of motion of the camshaft adjuster. Furthermore, such a Rotationstilger u. U. a reduced installation space, since this changes its configuration only slightly or not at all in the course of its repayment movement.

A particularly simple embodiment of a vibration damper as Rotationsstilger results when the mass and the intermediate body are formed approximately hollow cylinder linderförmig. In this case, the mass is firmly bonded to an outer surface of the intermediate layer. The intermediate layer is bonded to the component of the camshaft adjuster in the region of an opposing outer surface.

For a first embodiment, this may for example be such that the intermediate body is connected via its end faces on the one hand to the mass and on the other hand to the associated component of the camshaft adjuster, so that the aforementioned components are arranged axially adjacent to each other.

- For an alternative embodiment, the aforementioned components are nested radially into one another, wherein the intermediate body in the region of a radially outer circumferential surface and in the region of a radially inner circumferential surface is connected to the mass or the camshaft adjuster associated component.

The production and / or assembly possibilities for the camshaft adjuster according to the invention can be improved by reducing the vibration supply damper is firmly bonded to a cover of the camshaft adjuster.

In the event that the vibration absorber is materially connected to a drive wheel of the camshaft adjuster, can u for the vibration damper. U. large diameter of the drive wheel in the region of the junction to be exploited, so that caused by the vibration damper forces in the connection area have a large lever arm. This can u. U. the vibration damper can be designed with reduced dimensions and / or the eradication effect can be strengthened.

A particularly suitable connection point for the vibration damper is, for example, given by an axial extension of the drive wheel, a surface inside of the toothing of the drive wheel or an outer Mantelflä- surface of a housing of the camshaft adjuster.

Advantageous developments of the invention will become apparent from the dependent claims and the entire description. Further features are the drawings - in particular the geometries shown and the relative dimensions of several components to each other and their relative arrangement and operative connection - refer. The combination of features of different embodiments of the invention or features of different claims differing from the chosen relationships is also possible and is hereby stimulated. This also applies to features that are shown in separate drawing figures or are mentioned in their description. These features can also be combined with features of different claims.

Brief description of the drawings

In the drawings, embodiments of the invention are shown schematically. Show it: 1 shows a first embodiment of a camshaft adjuster according to the invention in a longitudinal section H-II;

FIG. 2 shows the camshaft adjuster according to FIG. 1 in a front view;

FIG. 3 shows a second exemplary embodiment of the camshaft adjuster according to the invention in a longitudinal section IV-IV;

FIG. 4 shows the camshaft adjuster according to FIG. 3 in a front view;

FIG. 5 shows a third exemplary embodiment of a camshaft adjuster according to the invention in a longitudinal section Vl-Vl;

FIG. 6 shows the camshaft adjuster according to FIG. 5 in a front view;

7 shows a fourth exemplary embodiment of a camshaft adjuster according to the invention in a longitudinal section VIII-VIII and FIG

Figure 8 shows the camshaft adjuster according to Figure 7 in front view.

Detailed description of the invention

The invention relates to a camshaft adjuster of any type, for example in Flügelzellenbauart, Axialkolbenbauart or with a three-shaft, an eccentric or a swash plate gear, the adjusting movement is preferably brought about on the basis of a hydraulic actuator or an electric control unit.

Figure 1 shows a camshaft adjuster 1 with a drive wheel 2, which is connected via a traction means in drive connection with a crankshaft. The camshaft adjuster 1 has a Tilger 3, which is connected to an associated component 4, which is part of the power flow between the drive wheel 2 and a camshaft. For the embodiment shown in FIG Invention, the associated component 4 is formed as a drive wheel 2, while it is in the embodiment of Figure 5 in the component 4 is a lid 18. Notwithstanding the illustrated embodiments, the component 4 can be any component of the camshaft adjuster 1, provided that it is coupled to the power flow from the drive element to the output element. For example, the vibration damper (3) can also be integrated in a housing of the camshaft adjuster and / or the component (4) can be an element of a geared connection used in the camshaft adjuster.

The vibration damper 3 has a mass 5 and an elastic intermediate body 6, which is interposed between mass 5 and component 4, on. While the. Mass 5 is stiff, the elastic intermediate body 6 has elastic and / or damping properties.

For the exemplary embodiment illustrated in FIG. 1, the mass 5 is designed as a hollow-cylinder-shaped or annular metallic ring 7, which is arranged concentrically to a longitudinal axis 8-8 of the camshaft adjuster 1. The elastic intermediate body 6 is formed as a hollow cylindrical or annular ring 9 with a radial extent corresponding to the extension of the ring 7. The extent of the ring 9 in the direction of the longitudinal axis 8-8 is preferably smaller than that of the ring 7 and is half to one quarter of the extent of the ring 7 in the direction of the longitudinal axis 8-8. In the region of the left, normal to the longitudinal axis 8-8 oriented end face of the ring 9, this is cohesively and over a large area attached to the ring 7. In the area of the opposite end face, the ring 9 is firmly bonded to the component 4 over a large area.

For the embodiment shown in Figure 1, the drive wheel 2 has a substantially hollow cylindrical drive wheel body 10, which forms the drive toothing 11 radially outboard. Radially inwardly of the drive wheel 10, a housing 12 is formed, which emerges from the drive wheel 10 to the left in the axial direction according to FIG. The housing The housing 12 and the drive wheel body 10 are connected to one another via a radial, annular web 14 which surrounds the longitudinal axis 8-8. An inner circumferential surface 15 of the drive wheel body 10, an associated end face of the web 14 and the lateral surface 13 form a recess 16 in the circumferential direction about the longitudinal axis 8-8, which is U-shaped in the longitudinal half section from the drive wheel 2.

The vibration damper 3 is inserted into the recess 16 in such a way that it terminates approximately flush with the drive wheel body 10 in the axial direction, wherein the elastic intermediate body 6 is firmly bonded to the web 14. The elastic intermediate body 6 and the mass 5 have a radial clearance both with respect to the lateral surface 13 and with respect to the lateral surface 15. During operation of the camshaft adjuster 1, as a result of the elastic intermediate body 6, the mass 5 can rotate relative to the drive wheel 2 about the longitudinal axis 8-8, the elastic intermediate body 6 being subjected to shear in this case.

In contrast to the embodiment shown in Figure 1, the mass is also used in the recess 16a, but the elastic intermediate body 6a radially inwardly bonded to the lateral surface 13a of the housing 12a cohesively, while the mass 5a cohesively on a cylindrical outer surface of the elastic intermediate body 6a is connected. In this case, mass 5a and elastic intermediate body 6a form a radial gap to the lateral surface 15a and an axial gap to the web 14a. Mass 5a and elastic intermediate body 6a are slightly out of the drive wheel 2a in the axial direction to the left.

According to the embodiment shown in Figure 5 drive wheel 2b and housing 12b are fixedly connected via a fastening means, here a screw 17, with a lid 18 which at least partially closes the housing 12b to the outside. In this case, the elastic intermediate body 6b formed as an annular body with a relatively large radial extent. The elastic intermediate body 6b is materially connected to the axially outer end face of the lid 18 and carries cohesively on the cover 18 opposite end face the mass 5b, which is also formed with respect to the previous embodiments, increased radial extent. Mass 5b and elastic intermediate body 6b have a central bore, in which a further cover 19 extends and through which this can be mounted, wherein the cover 19 can close a remaining opening or bore of the lid 18.

Notwithstanding the embodiment shown in Figure 5, the lid 18 may also be omitted, so that the elastic intermediate body 6b and the mass 5b replace the functions of the lid 18, if the elastic intermediate body 6b is tightly connected to the housing 12b. In this case, the dekelkel 19 can be used for example in the mass 5b, whereby both covers 18, 19 co-determine the mass moment of inertia of the mass 5b. For the embodiment shown in Figure 5, the lid 18, which is rotatably connected to the drive wheel 2b, the component 4b associated with the camshaft adjuster.

In the embodiment illustrated in FIGS. 7 and 8, the component 4c of the camshaft adjuster 1c, which is connected to the vibration absorber 3c, is formed by the drive wheel 2c, wherein the drive wheel has an axial, hollow-cylindrical extension 20 in the region of the drive wheel body 10c starting from the drive wheel body 10c projects beyond the housing 12c, lid 18c and lid 19c. The cylindrical lateral surface 21 of the extension 20 is cohesively connected to a corresponding cylindrical inner surface of the elastic intermediate body 6c. Radially outwardly a cylindrical lateral surface of the elastic intermediate body 6c is cohesively connected to the mass 5c. The vibration absorber 3c in this case is located approximately at the radial distance of the teeth of the drive wheel 2c from the longitudinal axis 8c-8c. The elastic intermediate body 6 is formed for example as a rubber ring. A substance-coherent compound can be made in particular by vulcanization or an extrusion process. The mass 5 may be one made of steel or metal or lead. The elastic intermediate body 6 is preferably made of rubber, plastic, rubber or an elastomeric material. Preferably, materials 5 with a higher specific weight than the intermediate body 6 are used for the mass.

LIST OF REFERENCE NUMBERS

1 camshaft adjuster

2 drive wheel

3 vibration absorber

4 component

5 mass

6 elastic intermediate body

7 ring

8 longitudinal axis

9 ring

10 drive wheel body

11 drive toothing

12 housing

13 lateral surface

14 footbridge

15 lateral surface

16 recess

17 screw connection

18 lids

19 lids

20 extension

21 lateral surface

Claims

claims

1. A camshaft adjuster for an internal combustion engine, wherein the relative angular relationship between a drive element, which is drive-engageable with a crankshaft, and an output member, which is driveably engageable with a camshaft, via an actuator is variable, characterized in that the camshaft adjuster (1) has a vibration damper (3) which is supported against an associated component (4) of the camshaft adjuster (1).

2. Camshaft adjuster according to claim 1, characterized in that the vibration damper (3) is firmly bonded to the associated component (4) of the camshaft adjuster (1).

3. camshaft adjuster according to claim 1 or 2, characterized in that the vibration damper (4) comprises a mass (5) made of a rigid material and an elastic intermediate body (6), which materially coherent with the associated component (4) of the camshaft adjuster

(1) and to the mass (5) is connected.

4. Camshaft adjuster according to one of the preceding claims, characterized in that the vibration absorber (4) is a Rotationsstilger.

5. Camshaft adjuster according to claims 4, characterized in that the mass (5) is formed as an approximately wood-cylindrical ring (7), the intermediate body (6) is formed as an approximately wood-cylindrical ring (9), the mass (5) cohesively on an outer surface of the intermediate body is attached (6) and the intermediate body (6) in the region of an opposite outer surface is firmly bonded to the component (4) of the camshaft adjuster (1).

6. Camshaft adjuster according to one of the preceding claims, characterized in that the vibration damper (3) is integrally connected to a cover (18) of the camshaft adjuster (1).

7. Camshaft adjuster according to one of claims 1 to 5, characterized in that ^" the vibration damper (3) is materially connected to a drive wheel (2) of the camshaft adjuster (1).

8. camshaft adjuster according to claim 7, characterized in that the vibration damper (3) cohesively with an axial extension (20) of the

Drive wheel (2) is connected.

9. camshaft adjuster according to claim 7, characterized in that the vibration damper (3) radially inwardly of the drive toothing (11) of the drive wheel (2) is arranged.

10. Camshaft adjuster according to one of claims 1 to 5, characterized in that the vibration damper (3) is firmly bonded to an outer circumferential surface (13) of a housing (12) of the camshaft adjuster (1).