WO2015162119A1

WO2015162119A1 - Valve actuation device for an internal combustion engine

Info

Publication number: WO2015162119A1
Application number: PCT/EP2015/058575
Authority: WO
Inventors: Jürgen GELTER; Andreas Zurk
Original assignee: Avl List Gmbh
Priority date: 2014-04-24
Filing date: 2015-04-21
Publication date: 2015-10-29
Also published as: JP6656169B2; DE112015001383A5; AT515734B1; AT515734A1; JP2017514065A

Abstract

The invention relates to a valve actuation device (1) for a reciprocating piston internal combustion engine with at least one gas exchange valve per cylinder, said valve being actuatable via a camshaft (2). The camshaft (2) has at least one cam piece (3) which is rotationally fixed in an axially movable manner via a valve stroke switching device (7) and which comprises at least two different cam contours (4, 5). The valve stroke switching device (7) has at least one transmitter part (8) which can be axially moved at a distance to the cam shaft axis (2a) and interacts with a receiver part (9) connected to the cam piece (3). A simple and compact switch of the valve stroke is allowed by designing both the transmitter part (8) as well as the receiver part (9) in a rotationally symmetrical manner, said transmitter part (8) being mounted in a movable and rotational manner about an axis (12) parallel to the camshaft axis (2a).

Description

Valve operating device for an internal combustion engine

The invention relates to a valve actuating device for an internal combustion engine having at least one cylinder with at least one gas exchange valve, which is actuated via a camshaft, wherein the camshaft has at least one axially displaceable over a Ventilhubumschalteinrichtung rotatable cam piece with at least two different cam contours, wherein the Ventilhubumschalteinrichtung at least one of the Has camshaft axis spaced axially displaceable encoder part, which cooperates with a connected to the cam piece driver part.

From DE 10 2004 055 852 AI a valve train for an internal combustion engine with a camshaft is known, wherein the camshaft has a Ventilhubumschalteinrichtung axially displaceable cam devices with different cam contours. The shift takes place via shift forks, which act via shift fingers on the cam devices.

From DE 42 30 877 AI a control device for charge exchange valves is known in which a cam carrier rotatably and axially displaceably arranged on a basic shaft. The cam carrier consists of a tubular support on which at least one cam is arranged, in which emerge from a common base circle axially offset several different cam tracks. By the axial displacement of the cam carrier on the fundamental shaft, a gas exchange valve is actuated by the differently shaped cam tracks, wherein the cam tracks may differ in the Hubkontur and / or in the phase position.

From the document DE 101 48 243 AI a development of this device is described, wherein it is disclosed that the base camshaft and the cam carrier are connected by an axially extending plurality of toothing, wherein the camshaft has an external toothing and the cam carrier has an internal toothing.

DE 10 2011 003 024 AI describes a sliding cam system with sliding cam, which are arranged axially displaceably on a camshaft of a reciprocating internal combustion engine. To adjust the sliding cam, a stationary electromagnetic adjustment device having an actuator pin is provided, wherein the actuator pin engages in displacement grooves, which are in operative connection with the sliding cams. To lock the sliding cam designed as Reibarretierung locking device is provided. Furthermore, from DE 10 2011 101 871 AI a valve drive for internal combustion engines for the actuation of gas exchange valves is known, which is constructed from a lever axis, with at least one lever mounted thereon and from an adjusting shaft. On the rotatable adjusting a sleeve with a guideway is rotatably mounted, but axially displaceable, wherein the lever is supported directly or indirectly in the guideway. A housing-fixed engagement element engages permanently in the guideway and supports the sleeve relative to the housing. Another engagement element engages radially along the guideway to the housing-fixed engagement element offset permanently into the guideway and is firmly connected to the lever. The switching between different cams of a cam group takes place by turning the adjusting shaft.

DE 10 2011 101 868 AI discloses a device for variation of the charge- changeover valve stroke in an internal combustion engine, wherein for the axial displacement of a cam carrier on the camshaft a parallel to the camshaft arranged adjusting shaft is provided. On the adjusting shaft is rotationally fixed, but axially adjustable, a first transmission element arranged, which has a guideway. Upon rotation of the adjusting a first engagement element is guided along the guide track, which is fixedly connected to the housing of the internal combustion engine. Furthermore, upon rotation of the adjusting shaft along the guide track, a second engagement element is guided, which is arranged for axial displacement of the cam carrier on a second transmission element.

The object of the invention is to enable a simple and compact switching of the valve.

According to the invention this is achieved in that both the transmitter part, and the driver part are rotationally symmetrical, wherein the transmitter part is mounted rotatably and displaceably about an axis arranged parallel to the camshaft axis.

The transmitter part can thereby be displaced axially by a displacement device, which in turn displaces the driver part together with the cam piece along the camshaft, wherein preferably the displacement device has at least one curved track element and at least one actuating pin interacting with the curved track element.

A particularly simple switching of the valve lift can be achieved if the transmitter part has on a first end face a first curved track element, preferably formed by a screw thread, wherein a see a rest position and an actuating position displaceable in a stationary part mounted first actuating pin in the operating position in the region of the first curved path is extendable. Similarly, the transmitter part on a second end face facing away from the first end face a - preferably formed by a screw - have second curved path element, wherein a slidably mounted between a rest position and an actuating position in a stationary part second actuating pin in the operating position in the region of the second Curved track is extendable. Each curved path element extends over an angle of at most 360 ° about the axis of rotation of the encoder part. A simple adjustment can be achieved if the first curved track element and the second curved track element have opposite slopes. Preferably, at least one actuating pin is arranged to be radially displaceable in the axis of the rotary member, and is hydraulically deflected against a return force formed by a return element, preferably a spring, wherein preferably the rest position is defined by the restoring force.

The transmitter part and the driver part are advantageously rotationally coupled. In the context of the present disclosure, rotationally coupled means that rotary movements of the transmitter part are transmitted to the driver part and vice versa. This rotational coupling can be done particularly easily by the transmitter part has a first gear and the driver part has a second gear, wherein the first and second gear are in meshing engagement.

An axial coupling between the transmitter part and the driver part is achieved in a simple manner if the transmitter part or the driver part in the region of its end faces has two axially spaced thrust washers, which span a space, the driver part or transmitter part in this space between the two thrust washers intervenes. Axial coupling means in the context of the present disclosure, that is moved with movements of the encoder part in the axial direction of the driver part, and vice versa. The thrust washers are arranged, for example, on the transmitter part, whereby the transmitter part by means of the thrust washers comprises the driver part like a fork. Of course, a kinematic reversal is possible by the thrust washers are arranged on the driver part.

Preferably, the thrust washers are arranged on both sides of the first and second gear, wherein the diameter of the thrust washers are larger than the Zahnfußkreisdurchmesser, preferably larger than the Zahnkopfkreisdurchmesser, the adjacent first and second gear. Thus, the thrust washers act in an adjustment on the flanks of the engaging gear and thus displace the driver part, which is preferably connected via a press fit with the cam piece.

The cam piece can be locked by a locking device in at least one, preferably each cam contour position, wherein at least one, preferably each cam contour position can be defined by a stop, which is formed for example by the camshaft.

The displacement is initiated by the extension of the first or second actuating pin. In the actuation position, the corresponding first or second actuation pin comes into contact with the first or second cam track. The rotation of the camshaft is transmitted to the transmitter via the two gears. Trained as a helical cam track is located on the stationary mounted actuating pin, by the rotational movement of the encoder part and the cam track of the encoder member is deflected axially. About the thrust washers, the axial deflection of the encoder part is transmitted to the driver part and thus axially displaced the cam piece on the camshaft, which can be exchanged between two juxtaposed cam contours for the actuation of the respective gas exchange valve. Basically, by providing additional actuating pins using the solution according to the invention also changing between more than two cam contours possible.

The invention is explained in more detail below with reference to a non-limiting exemplary embodiment shown in the figures. Show it

Fig. 1 a valve actuating device according to the invention in a

Tilt;

2 shows the valve actuating device in a longitudinal section.

3 shows a transmitter part together with axis in a plan view in a first embodiment;

FIG. 4 shows this transmitter part together with the axis in a section along the line IV-IV in FIG. 3; FIG.

5 shows a transmitter part together with axis in a plan view in a first embodiment; and

6 this transmitter part together with axis in a section along the line VI - VI in Fig. 5th

1 and 2 show a valve actuating device 1 for a reciprocating internal combustion engine, not shown, wherein the valve actuating Device 1 has a camshaft 2 rotatable about a camshaft axis 2a with a cam piece 3, which is non-rotatably connected to the camshaft 2, but arranged axially displaceably on this. The cam piece 3 has at least two axially arranged side by side, different cam contours 4, 5, wherein each one of the two cam contours 4, 5 with a cam follower 6 - for example, a roller tappet - for actuating a gas exchange valve not shown is engaged.

For switching between the two cam contours 4, 5 a Ventilhub- switching device 7 is provided, which has a transmitter part 8 and a fixedly connected to the cam piece 3 driver part 9, wherein Gebgeber part 8 and driver part 9 are rotationally symmetrical.

The transmitter part 8 has a first gearwheel 10, the driver part 9 has a second gearwheel 11, wherein the transmitter part 8 together with the first gearwheel 10 is mounted rotatably and axially displaceably mounted on a stationary axle 12. The first gear 10 and the second gear 11 are meshed with each other and are thereby rotationally coupled. At each end face 8a, 8b of the encoder part 8 a thrust washer 13, 14 is arranged, wherein the thrust washers 13, 14 directly adjoin the first gear 10. The diameter D of the thrust washers 13, 14, which are the same size in the embodiment (but may also be different), are greater than the Zahnfußkreisdurchmesser d _f , in particular larger than the Zahnkopfkreisdurchmesser d _{k of} the first gear 10. In one between the thrust washers formed free space 15 engages the driver part 9 a. The meshing part of the driver part 9 is on both sides by the two thrust washers 13, 14, which allows an axial displacement of the driver part 9 by the transmitter part 8. Geberteil 8 and driver part 9 are thus axially coupled.

The transmitter part 8 can be moved axially by a displacement device 30, which in turn also the driver part 9 together with the cam piece 3 is moved along the camshaft 2. In the region of the first end face 8a on the outside of the stop disk 13, the transmitter part 8 has a first curved track element 16 formed by a screw thread. A first actuating pin 17 is mounted radially displaceable in the axis 12 between a rest position A and an actuating position B. In the rest position A is the first actuating pin 17 entirely within the axis 12, wherein it is held by a likewise completely disposed within the axis 12 first return element in the form of a first return spring 18 in this rest position A. Similarly, the transmitter part 8 in the region of its second end face 8b on the outside of the thrust washer 14 on a likewise formed by a screw second cam member 19. Under cam member 16, 19 is understood in the present disclosure, an element with a running on the outside of the axis 12 guideway, starting from a near the first gear 10 arranged starting point in the axial (axis of rotation 8 'of the axis 12), from the gear 10th upward direction around the axis 12 winds up to an end point further from the first gear 19. The guideway can have a constant, but also a changing pitch. During a screw thread, the guideway winds at a constant pitch around the axis 12.

A second actuating pin 20 is also mounted radially displaceable in the axis 12 between a rest position A and an actuating position B. In the rest position A is the second actuating pin 20 entirely within the axis, being held by a completely disposed within the axis 12 second return element in the form of a second return spring 21 in this rest position A.

The first curved path element 16 and the second curved path element 19 are fixedly connected to the transmitter part 8 or its thrust washers 13, 14. The screw threads of the first curved track element 16 and of the second curved track element 19 have opposing pitches, as shown in FIGS. 3 to FIG. 6 is recognizable. Each of the two curved path elements 16, 19 extends over an angle β of at most 360 °, about the axis of rotation 8 'of the encoder part 8. FIGS. 3 and 4 show an embodiment in which the rising curved path elements 16, 19 are approximately extend around half the circumference - the angle ß about the axis of rotation 8 'is thus about 180 °. In FIG. 5 and FIG. 6 illustrated embodiment, the curved path elements 16, 19 are each formed by a full flight and thus extended by an angle ß of about 360 ° about the axis of rotation 8 '.

Each actuating pin 17, 20 is adjacent to a pressure chamber 22, 23, which is acted upon by oil. The idle state A of an actuating pin 17, 20 is defined by the pressure-free state of the respective pressure chamber 22, 23. When increasing the pressure in the pressure chamber 22, 23, the corresponding first actuating pin 17 and second actuating pin 20 is pushed from the rest position A to the actuating position B radially outward, wherein it projects into the region of the corresponding first and second curved path element 16, 19. The term "area of the first curved track element 16" or "second curved track element 19" is understood to mean that section in the axial direction along the axis 12 which is swept by the respective curved track element 16, 19 during (at least) one complete rotation of the encoder part 8 about the axis of rotation 8 '. By coupled to the camshaft 2 rotational movement of the encoder part 8 and the curved path elements 16, 19, the first curved path element 16 or the second curved path element 19 are pressed against the corresponding actuating pin 17, 20. Since the transmitter part 8 is mounted axially displaceably on the axis 12, the transmitter part 8 is axially displaced by the interaction of actuating pin 17, 20 and cam member 16, 19. With the displacement of the encoder part 8 and the driver part 9 and thus the cam piece 3 is moved. First actuating pin 17 and second actuating pin 20 are pressed against the same, which is in each case one of the two actuating pins 17, 20 in the rest position A and the other in the operating position B.

In order to hold the cam piece 3 in each case in a position, a locking device 24 is provided, which has at least one spring clip 25 which engages elastically in grooves 26, 26 'of the cam piece 3. The cam contour of the cam piece 3 are additionally defined by stops 27, 28 of the camshaft 2, which are arranged on opposite sides of the driver part 9 and the cam piece 3. In the area of at least one of these stops 27, 28, the spring clip 25 is fixed to the camshaft 2.

The displacement of the cam piece 3 is initiated by the extension of the first actuating pin 17 or the second actuating pin 20. In the actuation position B, the corresponding first or second actuating pin 17, 20 comes into contact with the first and second curved path element 16, 19. The rotation of the camshaft 2 is transmitted via the two gears 10, 11 to the transmitter part 8. The cam track 16 or 19 is located on the respective stationary mounted actuating pin 17, 20, by the rotational movement of the encoder part 8 and the cam track 16, 19, the transmitter part 8 is axially deflected. About the thrust washers 13, 14, the axial deflection of the encoder part 8 is transmitted to the driver part 9 and thus the cam piece 3 axially displaced on the camshaft 2, whereby between the cam contours 4, 5 can be changed for the actuation of the respective gas exchange valve.

Claims

PATENT APPLICATIONS

1. Valve actuating device (1) for a reciprocating internal combustion engine with at least one gas exchange valve per cylinder, which is actuated via a camshaft (2), wherein the camshaft (2) at least one via a Ventiihubumschaiteinrichtung (7) axially displaceable rotationally fixed cam piece (3) with at least two different cam contours (4, 5), wherein the Ventiihubumschaiteinrichtung (7) at least one of the camshaft axis (2a) spaced axially displaceable transmitter part (8), which cooperates with a with the cam piece (3) driver part (9), characterized in that both the transmitter part (8) and the driver part (9) are rotationally symmetrical, the transmitter part (8) being mounted such that it can be rotated and displaced about an axis (12) arranged parallel to the camshaft axis (2a).

2. Valve actuating device (1) according to claim 1, characterized in that the transmitter part (8) by a displacement device (30) is axially displaceable, whereby the driver part (9) together with the cam piece (3) along the camshaft (2) is displaceable, wherein preferably, the displacement device (30) has at least one curved path element (16, 19) and at least one actuating pin (17, 20) cooperating with the curved path element (16, 19).

3. Valve actuating device (1) according to claim 2, characterized in that the transmitter part (8) on a first end face (8 a) - preferably formed by a screw - first curved path element (16), wherein between a rest position (A) and an actuating position (B) displaceable in a stationary part mounted first actuating pin (17) in the operating position (B) in the region of the first cam track (16) is extendable.

4. Valve actuating device (1) according to claim 3, characterized in that the transmitter part (8) on one of the first end face (8 a) facing away from the second end face (8 b) - preferably formed by a screw - second curved path element (19), wherein a between a rest position (A) and an actuating position (B) displaceable in a stationary part mounted second actuating pin (20) in the operating position (B) in the region of the second curved path (19) is extendable.

5. Valve actuating device (1) according to claim 4, characterized in that the first curved track element (16) and the second curved track element (19) have opposite slopes.

6. Valve actuating device (1) according to one of claims 1 to 5, characterized in that extending at least one curved path element (16, 19) over an angle (ß) of a maximum of 360 ° about the axis of rotation (8 ') of the encoder part (8) ,

7. Valve actuating device (1) according to one of claims 1 to 6, characterized in that the transmitter part (8) and the driver part (9) are rotationally coupled.

8. Valve actuating device (1) according to claim 7, characterized in that the transmitter part (8) has a first gear (10) and the driver part (9) has a second gear (11), wherein first and second gear (10, 11) in Meshing.

9. valve actuating device (1) according to one of claims 1 to 8, characterized in that the transmitter part (8) or the driver part (9) in the region of its end faces (8a, 8b) has two axially spaced thrust washers (13, 14), which span a free space (15), the driver part (9) or transmitter part (8) engaging in this free space (15) between the two stop disks (13, 14).

10. valve actuating device (1) according to claim 9, characterized in that the thrust washers (13, 14) on both sides of the first and second gear (10, 11) are arranged, wherein the diameter (D) of the thrust washers are larger than the Zahnfußkreisdurchmesser ( d _f ), preferably as the Zahnkopfkreisdurchmesser (d _k ), of the adjacent first and second gear (10, 11).

11. Valve actuating device (1) according to one of claims 1 to 10, characterized in that the driver part (9) on the cam piece (3) is pressed.

12. Valve actuating device (1) according to one of claims 1 to 11, characterized in that the cam piece (3) by a locking device (24) is lockable at least in one, preferably in each cam contour position.

13. Valve actuating device (1) according to one of claims 1 to 12, characterized in that at least one, preferably each, cam Contour position of the cam piece (3) by a stop (27, 28) is defined, wherein preferably at least one stop (27, 28) through the camshaft (2) is formed.

14. Valve actuating device (1) according to one of claims 2 to 13, characterized in that at least one actuating pin (17, 20) in the axis (12) is mounted radially displaceable.

15. Valve actuating device (1) according to one of claims 2 to 14, characterized in that at least one actuating pin (17, 20) is hydraulically deflectable against a return element formed by a restoring element, preferably a spring (18, 19) restoring force, preferably the Rest position (A) of the actuating pin (17, 20) is defined by the restoring force.

2015 04 21

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