EP2715078B1 - Camshaft adjustment device - Google Patents

Description

The present invention relates to a camshaft adjusting device according to the preamble of patent claim 1, comprising a camshaft rotational axis defined by a camshaft, in particular a carrier shaft of a camshaft, about which the camshaft is rotatable

Due to the limited installation space in the region of a displacement motor of a motor vehicle, there is frequently the need to implement the electromagnetic multi-plunger adjusting device comprising a plurality of (typically selectively, ie independently) controllable plunger units sufficiently compact, so that on the one hand a sufficient electromagnetic functionality is ensured (such with regard to the necessary setting stroke of the tappet units and reaction or switching times), on the other hand no unwanted mutual influence - mechanical or electromagnetic - is present.

From the DE 10 2007 040 677 A1 a camshaft adjusting device is known in which the cooperating with a respective drive unit ram units are arranged such that their respective ram longitudinal center axis intersects the axis of rotation of the camshaft. At the same time, the drive units are arranged offset in the circumferential direction of the camshaft, so that the ram longitudinal center axes of the ram units extend at an angle to each other. This results in a comparatively large necessary installation space. Also disadvantageous are manufacturing difficulties.

From the DE 10 2007 028 600 A1 is an optimized with respect to the installation space required electromagnetic multi-ram actuator for a Camshaft adjusting device known, wherein the installation space minimization results from the fact that the drive units are arranged such that the actuatable plunger units or the plunger longitudinal axes defined by the plunger units are arranged in parallel one behind the other in a row, wherein all the longitudinal axis of the plunger intersect the camshaft rotation axis. The known electromagnetic actuator for Nockenwellenverstellvorrichtungen has proven itself. In particular, the axially parallel arrangement of the tappet units to each other in contrast to the over the circumference of the camshaft staggered ram units, where the ram longitudinal axis intersect the camshaft axis of rotation represents an economic and systemic robust advantage, but the overlap area between ram unit and actuator is rather low. There are efforts to make the electromagnetic actuator of the camshaft adjusting even more compact and space-efficient, but the largest possible contact surface between the ram units and the associated drive units should be ensured.

The object of the present invention is therefore to provide a camshaft adjusting device, comprising an electromagnetic multi-plunger adjusting device according to the preamble of the main claim, which is still further optimized space, while ensuring that the largest possible overlap area (contact surface) between the attack side (drive side ) End sides of the plunger units and the attack surface of the respectively associated drive unit is given.

This object is achieved by the camshaft adjusting device having the features of the main claim. Advantageous developments of the invention are specified in the subclaims. In the context of Invention, all combinations of at least two of the features disclosed in the description, the claims and / or the figures.

The invention is based on the idea, in a camshaft adjusting device comprising an electromagnetic multi-plunger adjusting device, to arrange the mutually axis-parallel plunger units such that the plunger longitudinal axis of at least one of the plunger units in departure from the teaching of the prior art, preferably defined by a support shaft axis of rotation of the camshaft does not intersect, but is spaced apart in an imaginary plane in which the aforesaid axis of rotation lies and to which all ram longitudinal center axes extend perpendicularly, in particular by a dimension of more than 0.3 mm, preferably by more than 0.5 mm. Thus, the invention deliberately takes the supposed disadvantage of an off-center force application of the cam member, preferably axially relative to the aforementioned axis of rotation, in order to advantageously achieve a space-optimized arrangement of the drive units with associated ram units, the arrangement according to the invention the ram units advantageously ensures that the largest possible overlap between ram units and drive units is given.

Each drive unit is preferably formed by one, in particular permanent magnet, armature. Preferably, each armature is associated with its own coil (energizable winding), wherein also a Ausfertigungsform can be realized in the example according to the in the DE 20 2008 015 980 U1 described principle, several anchors are driven by a common coil.

As will be explained later, depending on the installation situation, it is possible to space only a single ram longitudinal center axis in the described plane from the rotation axis and to position the at least one further ram longitudinal center axis such that it intersects the axis of rotation. It is also possible to arrange the ram units (guided longitudinally displaceable) in such a way that not a single one of the ram longitudinal center axis intersects the axis of rotation. Likewise, it is feasible that a plurality of ram longitudinal center axes in the aforementioned plane, preferably spaced by the same amount from the axis of rotation of the camshaft, in particular a carrier shaft of the camshaft and at least one, preferably only one, Stößellängsmittelachse the axis of rotation intersects.

To be particularly advantageous, it has been found, in the case of spacing a plurality of ram longitudinal axis of the axis of rotation of the camshaft to space each of them by the same amount in the aforementioned plane of the rotation axis. In the case of the spacing of at least two ram longitudinal center axes, it is particularly expedient to space them in opposite directions from the axis of rotation, ie to arrange such that at least one ram longitudinal center axis is spaced from the axis of rotation counter to the direction of rotation of the camshaft and at least one further in the direction of rotation. Even more preferred, in the case of the arrangement of an even number of ram longitudinal axis spaced from the axis of rotation of the camshaft, when they are evenly spaced in the two different directions (counter to the direction of rotation and in the direction of rotation) of the axis of rotation of the camshaft.

The drive of the elongated (even preferably cylindrical, more preferably realized from a metal material) ram units takes place in known per se, for example in the DE 10 2007 028 600 A1 described Way in that the ram units sit on an attack surface of a respective associated drive unit (preferably there adhere by means of magnetic effect) wherein the attack surface typically forms the distal end of an anchor unit of the respective drive unit.

To be particularly advantageous, it has been found that the at least one spaced in the aforementioned plane of the axis of rotation of the cam shaft ram longitudinal center axis is spaced by a minimum of 0.5 mm from the axis of rotation. Most preferably, the distance between 0.5 mm and 8.0 mm, preferably between 1.0 mm and 5.0 mm, even more preferably between 1.0 mm and 2.0 mm, most preferably the distance is about 1.5 mm. It is particularly preferred, in the case of the provision of a total of three tappet units, to space a relative to the longitudinal extent of the axis of rotation median tappet unit or its ram longitudinal axis of the axis of rotation of the shaft, and preferably by a selected from the aforementioned ranges of values, wherein still more preferably, the two other (outer) ram longitudinal center axes intersect the axis of rotation within the usual tolerances of less than 0.2 mm.

It is particularly preferred to space the at least one ram longitudinal center axis, preferably all ram longitudinal center axes spaced from the axis of rotation of the camshaft, in the plane to the camshaft rotational axis by a dimension, in particular the same amount, which is calculated on the basis of the base circle half diameter of the associated shift groove. Under the Grundkreishalbdurchmesser is half the diameter of an imaginary circle, on which the groove bottom of the switching groove extends to understand. Particularly preferably, the distance measured in the aforementioned plane is between about 3% and about 80%, preferably between about 3% and about 50%, even more preferably between about 3% and about 30%, even more preferably between about 3% and about 20% of this Grundkreishalbdurchmessers the respective ram unit associated, preferably spirally extending shift groove. In general, it is preferred if the distance is less than 15% of this base circle half diameter and / or more than 5%.

Very particular preference is given to an embodiment of the camshaft adjusting device, in which the multi-plunger adjusting device comprises a total of at least three, preferably only three, drive units, each with an associated plunger unit, wherein the at least three plunger units, in particular the exclusively three plunger units will be explained as follows can.

According to a first preferred embodiment, it is possible for only a single one of the plurality of ram longitudinal axis axes to arrange the camshaft rotational axis, the further ram longitudinal center axes, preferably the two further ram longitudinal axis in the previously explained plane of the camshaft of the axis of rotation, preferably spaced by the same amount. It is particularly expedient in the case of providing a total of three tappet units with respect to the longitudinal extent of the axis of rotation medium ram unit to arrange the axis of rotation cutting.

According to a second preferred embodiment variant, at least two, preferably only two of the at least three, in particular the only three push rod longitudinal central axes intersect the camshaft rotational axis. Preferably, these are two adjacent to one another in the direction of the longitudinal extent of the axis of rotation of the camshaft, that is to say adjacent ram longitudinal center axes.

According to a third variant, all of the at least three, preferably the only three ram longitudinal center axes in the aforementioned plane are spaced from the camshaft rotational axis, in particular by the same amount in each case.

It has proved to be particularly advantageous if the longitudinal axis of the longitudinal axis of the camshaft rotational axis arranged behind one another are arranged at the same distance from one another in this axial direction. In other words, each plunger longitudinal center axis defines a plunger plane that receives the respective plunger longitudinal center axis, the plunger planes arranged side by side in the direction of the longitudinal extension of the rotational axis being spaced apart by the same amount.

The arrangement of the plunger units becomes particularly compact in that at least one of the plunger units is seated eccentrically and / or with only a partial surface of the attack-side end face on the associated engagement surface with its attack-side end face.

Within the scope of a preferred embodiment, it has been found to be favorable that the drive units are assigned a common housing which particularly preferably interacts with a housing guide section on the front side, which guides-typically in the form of through openings running parallel to each other, in particular through-holes-guides for the several ram units offers, which are then to be arranged relative to each other and the camshaft rotation axis, that at least one push rod longitudinal axis does not intersect the aforementioned axis of rotation.

The result of the present invention in a surprisingly simple and elegant way, an arrangement which combines a compact design with ease of installation, high reliability and optimal switching and magnetic properties while ensuring generous overlap areas between the ram units and the drive units.

Fig. 1

eine stark schematisierte Gesamtdarstellung einer Nockenwellenverstellvorrichtung für eine Brennkraftmaschine mit variablem Gaswechselventiltrieb in einer teilweise geschnittenen Längsansicht,

Fig. 2

eine Nockenwellenverstelleinrichtung in einer Queransicht,

Fig. 3

eine Ansicht einer Stellvorrichtung einer Nockenwellenverstellvorrichtung in einer Ansicht von unten mit insgesamt drei Stößeleinheiten, wobei eine Stößellängsmittelachse einer mittleren Stößeleinheit zu einer Drehachse der Nockenwelle beabstandet ist,

Fig. 4

alternatives Ausführungsbeispiel einer Stellvorrichtung für eine Nockenwellenverstellvorrichtung, bei welcher zwei von drei Stößellängsmittelachsen auf unterschiedlichen Seiten von der Nockenwellendrehachse beabstandet sind, und

Fig. 5

ein weiteres alternatives Ausführungsbeispiel einer Mehrstößel-Verstellvorrichtung einer Nockenwellenverstellvorrichtung, bei welcher die Stößellängsmittelachse einer äußeren Stößeleinheit seitlich versetzt zur Drehachse der Nockenwelle angeordnet ist und die anderen beiden Stößellängsmittelachsen die Nockenwellendrehachse schneiden.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. These show in:

Fig. 1

a highly schematic overall view of a camshaft adjusting device for an internal combustion engine with variable gas exchange valve drive in a partially sectioned longitudinal view,

Fig. 2

a camshaft adjusting device in a transverse view,

Fig. 3

4 is a view from below of a control device of a camshaft adjusting device in a view from below, with a total of three tappet units, wherein a tappet longitudinal center axis of a central tappet unit is spaced from a rotational axis of the camshaft;

Fig. 4

alternative embodiment of an actuator for a camshaft adjuster, wherein two of three ram longitudinal center axes are spaced on different sides of the camshaft rotational axis, and

Fig. 5

a further alternative embodiment of a multi-ram adjustment of a camshaft adjusting device, wherein the ram longitudinal axis of an outer ram unit is laterally offset from the axis of rotation of the camshaft and the other two ram longitudinal axis axes intersect the camshaft axis of rotation.

The figures of the same element and elements with the same functions are denoted by the same reference numerals.

In the Fig. 1 and 2 are exemplary embodiments of variable gas exchange valve drives for a in Fig. 1 indicated internal combustion engine 2 shown. The Fig. 1 and 2 show possible embodiments of camshaft adjusting devices 3 with an electromagnetic multi-ram adjustment 4. The Nockenwellenverstellvorrichtungen 3 according to the Fig. 1 and 2 each comprise a camshaft 5, comprising a support shaft 6 on the rotationally fixed and axially displaceable cam piece 7 is arranged with a plurality of cam lobes of different geometry. The carrier shaft 6 is rotatably driven about a camshaft rotational axis D by means of the internal combustion engine 2. In the cam piece 7 spirally formed Schaltnuten 8 are introduced adjacent to the cam lobes, wherein the switching grooves 8 more in the embodiment shown 3 ram units 9, 10, 11 are assigned. Depending on the configuration of the camshaft adjusting device 3, a switching groove 8 can be assigned a single ram unit or a plurality of the ram units. The plunger units 9, 10, 11 can be coupled by means not shown separately drive units of the adjustment 4 in the switching grooves 8, thereby axially adjust the cam piece relative to the support shaft 6. Depending on the axial position of the cam piece 7 on the support shaft 6 different cam elevations of the cam piece 7 act with a cam follower 12 in a conventional manner to a spring-loaded in the closing direction gas exchange valve thirteenth

Each of the cylindrical, elongate plunger units 9, 10, 11 defines a plunger longitudinal center axis A1, A2, A3, wherein the plunger longitudinal center axes A1, A2, A3 are arranged parallel to one another and perpendicular to the camshaft rotational axis D.

The plunger units 9, 10, 11 each act with a side facing away from the cam piece 7, not shown (attack side or actuator side) end face in the in the DE 10 2007 028 600 A1 described in detail with each one drive unit together, more precisely with a plane attack surface of the respective drive unit. With regard to the arrangement and the interaction of the plunger units on the drive units is on the disclosure of the DE 10 2007 028 600 A1 Reference is made to the Applicant, the disclosure content of this document being deemed to be included in the present disclosure as belonging to the present invention.

The drive units not shown separately are accommodated in a common, cylindrical housing 14, which cooperates at the front with a housing guide portion 15 in which the plunger units 9, 10, 11 are guided longitudinally displaceable.

As it turned out Fig. 2 results is the ram longitudinal center axis A2 of a central (second) ram unit 10 in a plane E laterally spaced or arranged offset to the camshaft rotational axis D (axis of rotation), so this does not intersect. The aforesaid plane E receives the camshaft rotational axis D and extends perpendicular to all the longitudinal axis of the push rods A1, A2, A3. The other two (outer) and first and second plunger units 9, 11 are arranged such that they intersect the axis of rotation D in the plane E.

In Fig. 3 is an embodiment of a multi-plunger electromagnetic actuator 4 of an otherwise in Fig. 3 not shown camshaft adjusting device 3 shown in a view from below. Shown is the camshaft rotational axis D, which is arranged in a plane perpendicular to the longitudinal axis of the push rod A1 to A3 plane E. The ram units 9, 10, 11 are longitudinally displaceably guided in the guide section 15 of the housing such that the two outer longitudinal axes A1 and A3 viewed in the direction of the longitudinal extent of the camshaft rotational axis D intersect the camshaft rotational axis D in the plane E, whereas the longitudinal axis of the ram A2 of FIG the middle ram unit 10 is arranged laterally spaced from the camshaft rotation axis D and that by the dimension a, of about 1.5 mm in the embodiment shown. The two outer ram longitudinal center axes A1, A3 are in the direction of the axial extent of the camshaft rotational axis D equidistant from the central ram longitudinal center axis A2, by the dimension b of about 7 mm in the embodiment shown. The diameter of the circular-cylindrical ram units 9, 10, 11 is in the embodiment about 4.5 mm. The diameter of the hollow cylindrical housing 14 is about 20 mm.

In Fig. 4 an alternative embodiment of a multi-ram adjusting device 4 of a camshaft adjusting device 3 is shown. Recognizable again is the camshaft rotational axis D, which is arranged in the plane E, to which the ram longitudinal center axes A1 to A3 are perpendicular. In the exemplary embodiment shown, the plunger units 9, 10, 11 are arranged such that viewed in the direction of the longitudinal extent of the camshaft rotational axis D average (second) ram unit 10 or its Stößellängsmittelachse A2 intersects the camshaft rotational axis D in the plane E, whereas in the middle Stößellängsmitteachse A2 parallel ram longitudinal axis A1, A3 of the outer plunger units 9, 10 in the plane E are spaced from the camshaft rotation axis D and that by the same absolute dimension a, of about 1.5 mm in the embodiment shown. It can be seen that the outer ram longitudinal center axes A1, A3 are arranged on different sides of the camshaft rotational axis D. When viewed in the axial direction with respect to the camshaft rotational axis D, there are two adjoining ram longitudinal center axes A1, A2; A2, A3 equally spaced from each other and that measured by the direction of the camshaft rotation axis D dimension b of the illustrated embodiment 7 mm.

The embodiment according to Fig. 5 a multi-tappet adjusting device 4 a camshaft adjusting device 3 has with the embodiment according to Fig. 3 in common that only a ram longitudinal center axis in the plane E is spaced from the camshaft rotation axis D. In contrast to the embodiment according to Fig. 3 However, it is not about the average ram longitudinal center axis, but about an outer ram longitudinal center axis A1, here the first ram unit 9, while the push rod longitudinal axes A2, A3 of the middle (second) ram unit and the third ram unit 11 intersect the camshaft rotation axis D.

LIST OF REFERENCE NUMBERS

1

Gas exchange valve train

2

Internal combustion engine

3

Camshaft adjusting device

4

More plunger-positioning device

5

camshaft

6

carrier wave

7

cam piece

8th

shifting grooves

9

(first) ram unit

10

(second) ram unit

11

(third) ram unit

12

cam follower

13

Gas exchange valve

14

casing

15

Housing guide section

A1

(first) ram longitudinal center axis

A2

(second) ram longitudinal center axis

A3

(third) ram longitudinal center axis

D

Camshaft axis of rotation

a

Distance to the camshaft rotational axis transverse to the longitudinal extent of the camshaft rotational axis

b

axial distance in the direction of the longitudinal extent of the camshaft

Claims (12)

1. A camshaft adjustment device (3), comprising a camshaft rotation axis (D) and an electromagnetic multi-tappet actuating device (4) with at least two electromagnetic drive units, which for exerting an actuating force on a corresponding number of elongated tappet units (9, 10, 11) which are mounted axially parallel to one another, respectively defining a tappet longitudinal centre axis (A1, A2, A3) arranged perpendicularly to the camshaft rotation axis (D) are activatable in order to engage with the tappet units (9, 10, 11) in shifting grooves (8) of an adjustable cam piece (7), wherein the drive units respectively form a contact surface at a contact end facing a respectively associated one of the tappet units (9, 10, 11), which contact surface can be moved in an actuation direction of the drive units, and a contact-side end face of a respective one of the tappet units (9, 10, 11) facing away from the respectively associated shifting groove (8) cooperates with the contact surface,
   characterized in that
   at least one of the tappet units (9, 10, 11) is arranged relative to the camshaft rotation axis (D) such that its tappet longitudinal centre axis (A1, A2, A3) running parallel to the tappet longitudinal centre axes (A1, A2, A3) of the at least one other tappet unit (9, 10, 11) is spaced apart from the camshaft rotation axis (D) in a plane (E) receiving the camshaft rotation axis (D) and running perpendicularly to the tappet longitudinal centre axes (A1, A2, A3).
2. The camshaft adjustment device according to claim 1,
   characterized in that
   the at least one tappet longitudinal centre axis (A1, A2, A3) spaced apart from the camshaft rotation axis (D) in the plane is spaced by a distance measured perpendicularly to the camshaft rotation axis (D) of a range of values between 0.5 mm and 8.0 mm, especially between 1.0 mm and 5.0 mm, preferably between 1.0 mm and 2.0 mm.
3. The camshaft adjustment device according to one of the preceding claims,
   characterized in that
   the at least one tappet longitudinal centre axis (A1, A2, A3) spaced apart from the camshaft rotation axis (D) is spaced from the camshaft rotation axis (D) in the plane between 3 % and 80 %, especially between 3 % and 50 %, further preferably between 3 % and 30 %, further preferably between 3 % and 20 %, especially less than 15 %, preferably more than 5 %, of half the base circle diameter of the associated shifting groove (8).
4. The camshaft adjustment device according to one of the preceding claims,
   characterized in that
   at least three, preferably exclusively three, drive units with associated tappet units (9, 10, 11) are provided.
5. The camshaft adjustment device according to claim 4,
   characterized in that
   a single one of the tappet longitudinal centre axes (A1, A2, A3), preferably the tappet longitudinal centre axis (A1, A2, A3) of a central one of the tappet units (9, 10, 11) intersects the camshaft rotation axis (D).
6. The camshaft adjustment device according to claim 4,
   characterized in that
   at least two, preferably exclusively two, in particular two outer or two of the tappet longitudinal centre axes (A1, A2, A3) arranged adjacent to one another intersect the camshaft rotation axis (D).
7. The camshaft adjustment device according to one of the preceding claims,
   characterized in that
   all the tappet longitudinal centre axes (A1, A2, A3) are spaced from the camshaft rotation axis (D) in the plane.
8. The camshaft adjustment device according to one of the preceding claims,
   characterized in that
   each tappet longitudinal centre axis (A1, A2, A3) defines a tappet plane which is penetrated perpendicularly by the camshaft rotation axis (D), and that the distance measured in the direction of the longitudinal extent of the camshaft rotation axis (D) between respectively two adjacent ones of the tappet planes is identical in all respectively adjacent tappet planes.
9. The camshaft adjustment device according to one of the preceding claims,
   characterized in that
   at least one of the tappet units (9, 10, 11) sits with its end face on the contact side eccentrically and/or with only a partial surface of the end face on the contact side on the associated contact surface.
10. The camshaft adjustment device according to one of the preceding claims,
    characterized in that
    the drive units are arranged in a shared, preferably hollow-cylindrical housing (14).
11. The camshaft adjustment device according to one of the preceding claims,
    characterized in that
    the tappet units (9, 10, 11) are secured on the at least one actuator unit in a magnetically adhering manner.
12. The camshaft adjustment device according to one of the preceding claims,
    characterized in that
    the tappet units (9, 10, 11) have respectively a hardened engagement end entering into interaction with at least one of the shifting grooves (8).

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