EP3149292B1 - Valve drive with adustable camshaft - Google Patents

Description

The present invention relates to a valve control system having at least one adjustable camshaft, comprising an outer shaft and an inner shaft extending through the outer shaft, and having at least one phaser, comprising a first actuator and a second actuator rotatable against the first actuator, wherein the outer shaft and the Inner shaft are each connected to an actuator.

STATE OF THE ART

A generic type valve control system is known from DE 10 2008 005 292 A1 known. The valve control system has an adjustable camshaft, and the adjustable camshaft is composed of an outer shaft and an inner shaft, and on the outer shaft are rotatably received cam members which are connected via bolts with the inner shaft. If the inner shaft is twisted in the outer shaft, so rotate the cam elements on the outer shaft together with the inner shaft. Furthermore, there are fixedly arranged on the outer shaft cam elements, and the inner shaft is rotated in the outer shaft during operation of the valve control system by a phaser, so the timing can for example be determined separately from intake valves and exhaust valves.

To rotate the inner shaft in the outer shaft, the phaser serves. The phase adjuster comprises a first actuator, formed by a stator and a second actuator, formed by a rotor which is rotatably received in the stator. At the rotor a plurality of wing elements are arranged, and the wing elements can be applied hydraulically in vane, so that the rotation of the second actuator, so the rotor in the first actuator, ie in the stator, is possible.

By a coupling of the first actuator, for example with the outer shaft, and the second actuator, for example with the inner shaft, the rotation of the second actuator is transmitted in the first actuator to the adjustable camshaft.

During operation of a valve control system with an adjustable camshaft and with a phaser a rotation of the inner shaft in the outer shaft is often in a very short time, which is made possible by a correspondingly strong hydraulic loading of the wing elements in the hydraulic vane. Disadvantageously, this can lead to damaging attacks of the wing elements on the so-called early and late attacks, and the attacks are formed by the walls of the chambers in the stator. Just when large adjustment angles are required, wing elements must be mounted on the rotor, which are made relatively thin. In particular, thin executed wing elements can experience damage when a strong fluid loading for very short-term adjustment of the rotational position of the inner shaft in the outer shaft is required.

Further, adjustable camshafts have bolts for connecting the rotatable cam members to the inner shaft, and the bolts are passed through passages in the outer shaft. These passages have a limited longitudinal extent in the circumferential direction of the outer shaft, and the bolts can be rotated over the desired angle of rotation in the passages. In this case, the bolts can strike against the end regions of the passages, which can also lead to damage of the adjustable camshaft, so that a striking of the bolts on the passages is to be avoided.

GB 2 424 256 A discloses a phaser connected to the camshaft to allow relative movement of the inner shaft to the outer shaft. An angular position stop is integrated in a bearing sleeve which is arranged at one end of the camshaft. A pin-shaped element of the bearing sleeve engages in a recess of the outer shaft.

DISCLOSURE OF THE INVENTION

The object of the invention is the development of a valve control system with an adjustable camshaft and with a phaser, wherein the valve control system should be operable without damage at large displacement angles of the inner shaft in the outer shaft. In particular, damage caused by a Limiting the angle of rotation of the inner shaft can be avoided in the outer shaft.

This object is achieved on the basis of a valve control system according to the preamble of claim 1 in conjunction with the characterizing features. Advantageous developments of the invention are specified in the dependent claims.

The invention includes the technical teaching that at least a stop is provided, which is rotationally coupled to the outer shaft, and that at least one counter-stop is provided which is rotationally coupled to the inner shaft, wherein the maximum angle of rotation of the inner shaft in the outer shaft by a Adjacent of the stop to the counter-stop is determined.

The invention is based on the advantageous possibility, regardless of the limited angle of rotation of the second actuator in the first actuator of the phase adjuster and regardless of the limitation of a rotation angle of a bolt in a passage of the outer shaft to use a stop and a counter-stop, by the angle of rotation of the inner shaft is limited in the outer shaft of the adjustable camshaft and thus the second actuator in the first actuator of the phaser. According to the invention, a stop is provided, which can interact with a counter-stop, wherein the stop on the outer shaft and the counter-stop on the inner shaft are rotationally coupled. Similarly, a stop on the inner shaft can be provided, which can interact with a counter-stop on the outer shaft. The stop occurs mechanically interacting with the counter-stop by the stop has a surface which comes into contact against a counter surface on the counter-stop. The separate rotation angle limit allows a robust design, regardless of relatively thin wing elements in the phaser and regardless of the passage of bolts through passages in the outer shaft of the adjustable camshaft. Consequently, in particular, neither the wing elements in the phaser nor the bolts and the passages of the outer shaft must meet particular strength requirements, as a Angle of rotation limiting previously achieved according to the invention by the stop in interaction with the counter-stop.

The valve control system according to the invention may comprise one or more camshafts. For example, the valve control system may have two camshafts arranged parallel to one another, which are in particular coupled to one another. The coupling can be done for example via so-called dual-phaser, so that on one or both camshaft phasers are arranged and which can be in operative connection with each other. The stop according to the invention and the counter-stop can be arranged on one or both camshafts.

For example, the stop may be formed by at least one claw and the counter-stop may have projections between which at least one recess is formed. In this recess, the at least one claw may protrude. For example, the counter-abutment may be formed with a number of protrusions, by which an equal number of recesses is produced, and according to the number of recesses the abutment has an equal number of claws, so that, for example, a claw projects into each recess. Advantageously, the stop can be crown-like, and the counter-stop is formed in a star shape, so that the number of claws corresponds to the number of protrusions or recesses.

The valve control system may include a drive wheel disposed on the outer shaft and for rotationally driving the variable camshaft. In this case, a stop disc may be provided and accommodated on the drive wheel, which has at least one claw and preferably also a plurality of claws for forming the stop. The counter-stop can be arranged on the inner shaft and in particular in one piece as at least one projection, preferably also several times, be integrally formed thereon, and the projection or the projections can interact with the stop disc. In particular, the projections may extend into spaces between the claws formed on the stop disc. According to an alternative Variant to the formation of the stop and the counter-attack, the stop can be formed as a claw extension and arranged at the end of the outer shaft or formed on this. In this case, gaps can be formed between the claws of the claw extension. According to this variant, the counter-abutment can be formed by a pin element which is arranged corresponding to the claw extension on the inner shaft, wherein pins of the pin element can protrude radially outward into the interstices of the claw extension. The variant for the formation of the stop and the counter-attack, formed by a claw extension and a pin member, for example, without modification of existing camshaft constructions can be subsequently arranged on a valve control system, and for example, the claw extension can be integrally formed with the outer shaft and the pin member can, for example a screw on the front side of the inner shaft end attached.

According to an advantageous embodiment, the stop can have four claws or four claw extensions, and the counter-stop can have four recesses or four intermediate spaces. This gives the adjustable camshaft or the phaser a mechanically highly resilient stop that can be designed wear-resistant, and even with large hydraulic loads of the vane element of the phaser, the rotation angle limit of the inner shaft can be designed wear-free in the outer shaft.

To drive the valve control system, this can have a drive wheel, for example a sprocket or a toothed belt wheel. The drive wheel is used for rotating drive of the adjustable camshaft and is driven by the traction means, that is, for example via a chain or a toothed belt, through the crankshaft of an internal combustion engine. The stop can be integrated, for example, in the drive wheel. For this purpose, for example, the counter-stop in the hub region of the drive wheel may be formed on the inner shaft, wherein the drive wheel is connected to the outer shaft, for example, this may be welded to the tubular outer shaft. The projections of the counter-stop can point radially outward and with the example abut axially projecting claws on the stop disc. The claws can also be integrally formed with the drive wheel and, for example, integrally formed thereon.

According to a likewise advantageous variant of the stop and the counter-stop can be integrated in the phaser. For example, the stop disc on the phaser, for example, be arranged on the first actuator. The counter-stop can be arranged, for example, on the second actuator and interact with the claws on the stop plate.

The valve control system can be executed with the stop according to the invention and the counter-stop, that the limited by the stop or the counter stop angle of rotation of the inner shaft in the outer shaft is smaller than the maximum angle of rotation of the second actuator relative to the first actuator. In particular, on the outer shaft adjustable cam elements may be rotatably received, which are connected by a bolt with the inner shaft, wherein the bolts are passed through passages in the outer shaft, and wherein the limited by the stop and the counter-rotation of the inner shaft in the outer shaft is smaller as the maximum angle of twist of the bolts in the passages. This avoids that the first actuator forms a stop with the second actuator. Furthermore, it is avoided that the bolts form a stop in the passages of the outer shaft in order to limit the angle of rotation of the inner shaft in the outer shaft.

The invention further relates to an adjustable camshaft of a valve control system having an outer shaft and an inner shaft extending through the outer shaft, wherein a stop is provided, which is rotationally fixedly coupled to the outer shaft, and wherein a counter-stop is provided, which is provided with the inner shaft is coupled rotationally fixed, wherein the maximum angle of rotation of the inner shaft in the outer shaft is determined by an abutment of the stop against the counter-stop.

In this case, the stop can be formed as a claw extension and be arranged on the outer shaft end side or formed on this, wherein intermediate spaces may be formed between the jaws of the claw extension.

In particular, the counter-stop can be formed by a pin element, which can be arranged corresponding to the claw extension end to the inner shaft, wherein pins of the pin member protrude radially outwardly into the interstices of the claw extension.

The adjustable camshaft may be designed for coupling to a phaser, wherein the stop and / or the counter-stop can interact with the phaser. Furthermore, the adjustable camshaft, in particular the outer shaft, connected to a drive wheel or be made in one piece with this, and the stop and / or the counter-stop can interact directly or by appropriate means, for example with a stop disc with the drive wheel.

PREFERRED EMBODIMENT OF THE INVENTION

Figur 1

eine Querschnittsansicht durch ein Ventilsteuersystem mit einer verstellbaren Nockenwelle und einem Phasensteller,

Figur 2

eine Ansicht des Details Z gemäß Figur 1 in einer vergrößerten Darstellung,

Figur 3

eine Darstellung des Schnittes H - H gemäß Figur 1,

Figur 4

eine perspektivische Ansicht der Innenwelle mit einer Anschlagscheibe,

Figur 5

eine perspektivische Ansicht der Innenwelle ohne Anschlagscheibe,

Figur 6

eine perspektivische Ansicht der Anschlagscheibe,

Figur 7

eine quer geschnittene perspektivische Ansicht einer verstellbaren Nockenwelle mit einem Anschlag und einem Gegenanschlag gemäß einer weiteren Variante und

Figur 8

eine perspektivische Ansicht der Variante gemäß Figur 7 des Anschlages und des Gegenanschlages in einer nicht geschnittenen Darstellung.

Further, measures improving the invention will be described in more detail below together with the description of a preferred embodiment of the invention with reference to FIGS. It shows:

FIG. 1

a cross-sectional view through a valve control system with an adjustable camshaft and a phaser,

FIG. 2

a view of the detail Z according to FIG. 1 in an enlarged view,

FIG. 3

a representation of the section H - H according to FIG. 1 .

FIG. 4

a perspective view of the inner shaft with a stop plate,

FIG. 5

a perspective view of the inner shaft without stop disc,

FIG. 6

a perspective view of the stop plate,

FIG. 7

a cross-sectional perspective view of an adjustable camshaft with a stop and a counter-stop according to a further variant and

FIG. 8

a perspective view of the variant according to FIG. 7 of stroke and counter stroke in a non-cut representation.

FIG. 1 shows in a cross-sectional view of a valve control system 1 with an adjustable camshaft 10 and with a phaser 13. The adjustable camshaft 10 has an outer shaft 11 and an inner shaft 12, and the inner shaft 12 extends through the tubular outer shaft 11 therethrough. On the outer side of the outer shaft 11 cam elements 25 are rotatably received and rotatably connected with bolts 26 with the inner shaft 12, and the inner shaft 12 is rotated in the outer shaft 11, rotate with the inner shaft 12, the cam elements 25 on the outer side of the outer shaft eleventh

To generate the rotation of the inner shaft 12 in the outer shaft 11 of the phase adjuster 13, which is shown only schematically. In order to generate the rotation of the inner shaft 12 in the outer shaft 11, the phaser 13, a first actuator 14 and a second actuator 15, and the actuators 14 and 15 may be formed as a stator and a rotor and hydraulically acted upon, as shown in DE 10 2008 005 292 A1 known.

Adjacent to the phase adjuster 13, a drive wheel 20 is connected to the outer shaft 11, via which the camshaft 10 can be set in rotation. The adjustment of the angle of rotation of the inner shaft 12 in the outer shaft 11 takes place during operation of the camshaft 10, and to limit the rotational angle of the inner shaft 12 in the outer shaft 1, serves according to the embodiment shown a Stop disc 21, on which a stop 16 is formed, which can be brought into operative connection with a counter-stop 17 on the outer shaft 12. First, the detail Z shown will be in the following FIG. 2 described in more detail.

FIG. 2 shows the detail Z of the adjustable camshaft 10 with the outer shaft 11 and with the inner shaft 12 extending through the outer shaft 11, and there is shown a drive wheel 20 connected to the outer shaft 11. Not shown is different from FIG. 1 a phaser.

On a plan side of the drive wheel 20, a stop plate 21 is arranged via screw elements 30, and the stop plate 21 has stops 16 which protrude axially in the form of claws 18 from the plane of the stop plate 21 into the hub of the drive wheel 20 inside. The claws 18 are located over the outside of the inner shaft 12 and can interact with counter-attacks, as in connection with the following FIG. 3 explained in more detail, which is a section along the section line HH according to FIG. 1 represents.

FIG. 3 shows a cross section along the section line H - H by the drive wheel 20 according to FIG. 1 , wherein the cutting line is formed such that the claws 18 are to form the stop 16 of the stop plate 21 in the cutting plane. The cross-sectional view makes it clear that on the inner shaft 12 counterstops in the form of projections 27 are formed, which protrude radially from the inner shaft 12 to the outside and form the counter-stop 17. The projections 27 extend into recesses 19, which are formed between the claws 18 of the stop disc 21. If now the inner shaft 12 is rotated in the outer shaft 11, the projections 27 reach in the circumferential direction in abutment against the claws 18, so that the rotation of the inner shaft 12 is limited in the outer shaft 11.

The embodiment according to the FIGS. 1 to 3 shows a stopper plate 21 with four jaws 18 so that between the jaws 18 four recesses 19 are formed. In each of the recesses 19 projections 27 extend, so that four projections 27 are formed on the inner shaft 12.

FIG. 4 shows in a perspective view of the stop plate 21 in arrangement over the inner shaft 12, without the drive wheel 20 is shown for receiving the stop plate 21 with the outer shaft 11. Due to the reduced view, it can be seen that the projections 27 extend into the recesses 19 between the claws 18, whereby, analogously, the claws 18 of the stop disc 21 extend in spaces between the projections 27. Due to the thus enabled interaction of the jaws 18 with the projections 27, the angle of rotation of the inner shaft 12 is limited relative to the stop plate 21.

FIG. 5 shows without the stopper plate 21 according to FIG. 4 the inner shaft 12 with the projections 27, between which the recesses 19 are, whereby the counter-stop 17 is formed. The view shows four protrusions 27 integrally formed with the inner shaft 12 and, for example, the inner shaft 12 can be prepared by a turning operation, and the recesses 19 are then manufactured by intermittent milling.

FIG. 6 shows finally a perspective view of the stopper plate 21 with the axially projecting claws 18, and by the claws 18 of the stopper 16 is formed, which with the counter-stop 17 according to FIG. 5 can interact accordingly.

The FIGS. 7 and 8 show in a cut ( FIG. 7 ) and an uncut ( FIG. 8 ) Perspective view of a further embodiment of the formation of the stop 16 and the counter-stop 17, which are arranged on the end side of the adjustable camshaft 10 with the outer shaft 11 and the inner shaft 12. The stop 16 is formed in the form of a claw extension 22 at the end on the outer shaft 11, and by the claw extension 22 gaps 28 are formed. The end of the outer shaft 11 is thus formed approximately crown-shaped and there are two intermediate spaces 28 are exemplified. The counter-stop 17 is formed by a pin member 23, which corresponds to the claw extension 22 end to the inner shaft 12th is arranged. The pin member 23 has, by way of example, two pins 24 which are arranged diametrically opposite one another at 180 ° and project radially outward into the intermediate spaces 28 of the claw extension 22. If the inner shaft 12 is rotated in the outer shaft 11, the pins 24 come into contact with the edges of the intermediate spaces 28, whereby the angle of rotation is limited by the corresponding desired amount. The pin member 23 is attached via a screw 29 on the end side of the inner shaft 12 and thus designed as a single part.

LIST OF REFERENCE NUMBERS

1

Valve control system

10

adjustable camshaft

11

outer shaft

12

inner shaft

13

phaser

14

first actuator

15

second actuator

16

attack

17

counterstop

18

claw

19

recess

20

drive wheel

21

stop disc

22

Claw extension

23

pin element

24

spigot

25

cam member

26

bolt

27

head Start

28

gap

29

screw

30

screw

Claims (11)

1. Valve control system (1) with at least one adjustable camshaft (10) having an outer shaft (11) and an inner shaft (12) which extends through the outer shaft (11), and with at least one phase shifter (13) comprising a first actuating member (14) and a second actuating member (15) which can be rotated with respect to the first actuating member (14), the outer shaft (11) and the inner shaft (12) being connected to in each case one actuating member (14, 15), at least one stop (16) being provided which is coupled to the outer shaft (11) fixedly so as to rotate with it, and at least one counter-stop (17) being provided which is coupled to the inner shaft (12) fixedly so as to rotate with it, the maximum rotational angle of the inner shaft (12) in the outer shaft (11) being defined by way of butting of the stop (16) against the counter-stop (17), a drive wheel (20) for the rotational drive of the adjustable camshaft (10) being arranged on the outer shaft (11), and a stop-disc (21) being provided and being received on the drive wheel (20), which stop-disc (21) has at least one claw (18) for forming the stop (16).
2. Valve control system (1) according to Claim 1, characterized in that the stop (16) is formed by way of the at least one claw (18), and in that the counter-stop (17) has projections (27), between which at least one cut-out (19) is formed, into which the claw (18) protrudes.
3. Valve control system (1) according to Claim 1 or 2, characterized in that the counter-stop (17) is arranged on the inner shaft (12), and in particular is formed on it in one piece as at least one projection (27), and interacts with the stop-disc (21).
4. Valve control system (1) with at least one adjustable camshaft (10) having an outer shaft (11) and an inner shaft (12) which extends through the outer shaft (11), and with at least one phase shifter (13) comprising a first actuating member (14) and a second actuating member (15) which can be rotated with respect to the first actuating member (14), the outer shaft (11) and the inner shaft (12) being connected to in each case one actuating member (14, 15), at least one stop (16) being provided which is coupled to the outer shaft (11) fixedly so as to rotate with it, and at least one counter-stop (17) being provided which is coupled to the inner shaft (12) fixedly so as to rotate with it, the maximum rotational angle of the inner shaft (12) in the outer shaft (11) being defined by way of butting of the stop (16) against the counter-stop (17), the stop (16) being configured as a claw projection (22) and being arranged on the end side on the outer shaft (11) or being formed on the latter, intermediate spaces (28) being formed between the claws of the claw projection (22), and the counter-stop (17) being formed by way of a pin element (23) which is arranged on the end side on the inner shaft (12) in a manner which corresponds with the claw projection (22), pins (24) of the pin element (23) protruding radially to the outside into the intermediate spaces (28) of the claw projection (22).
5. Valve control system (1) according to one of the preceding claims, characterized in that the stop (16) has four claws (18) or four claw projections (22), and in that the counter-stop (17) has four cut-outs (19) or four intermediate spaces (28).
6. Valve control system (1) according to one of the preceding Claims 1 to 3, characterized in that the stop (16) is integrated into the drive wheel (20).
7. Valve control system (1) according to one of the preceding Claims 1 to 3 or 6, characterized in that the counter-stop (17) is configured on the inner shaft (12) in the hub region of the drive wheel (20).
8. Valve control system (1) according to one of the preceding claims, characterized in that the stop (16) and the counter-stop (17) are integrated into the phase shifter (13).
9. Valve control system (1) according to one of the preceding claims, characterized in that the rotational angle of the inner shaft (12) in the outer shaft (11), which rotational angle is limited by way of the stop (16) and the counter-stop (17), is smaller than the maximum rotational angle of the second actuating member (15) with respect to the first actuating member (14).
10. Valve control system (1) according to one of the preceding claims, characterized in that adjustable cam elements (25) are received rotatably on the outer shaft (11), which cam elements (25) are connected by way of a pin (26) to the inner shaft (12), the pins (26) being guided through passages in the outer shaft (11), and the rotational angle of the inner shaft (12) in the outer shaft (11), which rotational angle is limited by way of the stop (16) and the counter-stop (17), being smaller than the maximum rotational angle of the pins (26) in the passages.
11. Adjustable camshaft (10) of a valve control system (1) with an outer shaft (11) and with an inner shaft (12) which extends through the outer shaft (11), a stop (16) being provided which is coupled to the outer shaft (11) fixedly so as to rotate with it, and a counter-stop (17) being provided which is coupled to the inner shaft (12) fixedly so as to rotate with it, the maximum rotational angle of the inner shaft (12) in the outer shaft (11) being defined by way of butting of the stop (16) against the counter-stop (17), the stop (16) being configured as a claw projection (22) and being arranged on the end side on the outer shaft (11) or being formed on the latter, intermediate spaces (28) being formed between the claws of the claw projection (22), and the counter-stop (17) being formed by way of a pin element (23) which is arranged on the end side on the inner shaft (12) in a manner which corresponds with the claw projection (22), pins (24) of the pin element (23) protruding radially to the outside into the intermediate spaces (28) of the claw projection (22).

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