DE102014116194A1 - Valve drive for actuating gas exchange valves of an internal combustion engine - Google Patents

Abstract

The invention relates to a valve drive (1) for actuating gas exchange valves of an internal combustion engine with a first camshaft (10), which is rotatably received in a first shaft axis (11) and with a second camshaft (20) arranged in a second shaft axis (21). is rotatably received, wherein at least one of the camshafts (10, 20) as an adjustable camshaft (10, 20) is executed and an outer shaft (12, 22), in which an inner shaft (13, 23) is rotatably received, wherein at least one the camshafts (10, 20) are drivingly connected to a crankshaft (3) of the internal combustion engine via a drive means (2), and wherein a phase actuator (30) is provided, with at least one inner shaft (13, 23) in phase relative to Phase position of at least one outer shaft (12, 22) of the camshaft (10, 20) is variable. According to the invention, it is provided that the phase adjusting member (30) has an arrangement spaced apart from both shaft axes (11, 21).

Description

The present invention relates to a valve train for actuating gas exchange valves of an internal combustion engine with a first camshaft which is rotatably received in a first shaft axis and with a second camshaft which is rotatably received in a second shaft axis, wherein at least one of the camshafts is designed as an adjustable camshaft and an outer shaft, in which an inner shaft is rotatably received, wherein at least one of the camshafts is drivingly connected via a drive means with the crankshaft of the internal combustion engine, and wherein a phase actuator is provided, with the at least one inner shaft in its phase position relative to the phase position of at least one Outer shaft of the camshaft is variable.

STATE OF THE ART

The DE 10 2006 049 243 A1 describes a valve train for actuating gas exchange valves of an internal combustion engine with a first camshaft and a second camshaft, and the camshafts are arranged parallel to each other and designed as adjustable camshafts. Thus, both camshafts on an outer shaft, in each of which an inner shaft is rotatably received. On the outside of the outer shaft fixed cams are applied, which are rotatably connected to the outer shaft and continue to be added to the outer shaft adjusting cam, which are rotationally connected to the inner shaft. If the inner shaft is adjusted in the phase position with respect to the phase angle of the outer shaft, then the adjusting cam rotate relative to the fixed cam, so that the timing can be changed, for example, of intake valves and exhaust valves to each other.

The outer shafts of the adjustable camshafts are jointly driven by a drive means by a crankshaft of the internal combustion engine, so that the phase position of the two outer shafts is mutually unchangeable. On one of the two camshafts sits on the end of a phase actuator, and by the phase actuator, the inner shafts can be changed in their phase position relative to the phase angle of the outer waves. Disadvantageously, the structural complexity of a camshaft increases significantly when a phase actuator is arranged on one end side of the camshaft. The phase actuators are usually driven hydraulically, and by the co-rotation of the phase actuator with the rotational movement of the camshaft fluid passages must be created, which usually takes place via an adjacent to the phase actuator slide bearing. By several oil channels while the supporting cross-section of the outer shaft and / or the inner shaft is weakened, and also must be provided for the arrangement of the phase actuator on one end side of the camshaft, a corresponding space available. In particular, in the case of double-overhead camshafts in the cylinder head of an internal combustion engine, a so-called DOHC, the installation space for arranging a phase actuator is often severely limited. Consequently, it is desirable to simplify the construction and design effort to form a valve train, in particular designed as a DOHC valve train, and perform minimal construction space.

DISCLOSURE OF THE INVENTION

The object of the invention is the development of a valve train with two camshafts for actuating gas exchange valves of an internal combustion engine, and the valve train should have at least one adjustable camshaft and take up the smallest possible space. In particular, an improved constructive solution for the arrangement and control of a phase actuator is to be created.

This object is achieved on the basis of a valve train for actuating gas exchange valves of an internal combustion engine 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 the phase actuator has an arrangement spaced from both shaft axes.

The invention is based on the general idea to arrange the phase actuator separately to the camshaft, and the phase actuator is in particular not arranged directly on an inner shaft or on an outer shaft of the camshaft. Rather, the phase actuator is to be arranged with its adjusting axis so that the adjusting axis is arranged, for example, parallel, but spaced from both shaft axes. This results in the advantage that the phase actuator can be acted upon more easily with a control fluid, since the control fluid does not have to be guided by the inner shaft and / or the outer shaft, in particular no corresponding channels in the inner shaft and / or the outer shaft must be provided, so these do not weaken the bearing material cross section. The invention solves the above problem in particular in that the phase actuator can be arranged freely, with only transmission means are to be provided, with which the phase actuator can be coupled with at least one of the two camshafts.

For example, the phase actuator may have a stator and a rotor, and by applying fluid, the rotor in the stator may be rotated about the adjusting axis. In this case, the stator and the rotor can be rotatably arranged in a common adjusting axis, wherein the adjusting axis is arranged parallel spaced from the shaft axes of the camshafts. The rotor and / or the stator can intersect at least the outer shaft and / or the inner shaft of one of the camshafts, since the invention does not fundamentally claim that the phase actuator should be arranged in complete structural separation from the camshafts. Rather, only the adjusting axis should not lie in one of the shaft axes of the camshafts.

With particular advantage, the phase actuator can be operatively connected to the at least one inner shaft via a first transmission means. For example, the transmission means may be formed by a gear pair, wherein the transmission means may also be formed by a traction means or the like.

The valve train may be designed with two adjustable camshafts, and the camshafts may have a respective outer shaft and a respective inner shaft, in particular, both inner shafts are immutable to each other via the first transmission means in their phase position immutable. In particular, both inner shafts may be coupled to or via the phase actuator.

With further advantage, the outer shaft of the first camshaft and the outer shaft of the second camshaft with the drive means of the crankshaft of the internal combustion engine can be driven together. Consequently, the two outer shafts of the camshaft rotate in phase with each other, and the two inner shafts are also coupled to each other via the first transmission means and rotate in phase, so the phasing of the two inner shafts can be changed relative to the phase position of the two outer waves on the phase actuator.

The first transmission means may for example be connected to the rotor of the phase actuator, and the phase actuator may be operatively connected via a second transmission means with the outer shaft of one of the camshafts. In this case, the second transmission means can be connected to the stator of the phase actuator. Consequently, by activating the phase actuator, the phase position of a rotational movement transmitted via the first transmission means can be changed for rotational movement transmitted via the second transmission means. The particular advantage is that the two inner shafts of the camshaft can be changed in their phase position relative to the phase position of the two outer shafts on the separately arranged phase actuator.

According to a modified embodiment, it can also be provided that the first transmission means is connected to the stator of the phase actuator. In this case, the second transmission means can also be connected to the rotor of the phase actuator. Thus, according to this variant, the phase position of a rotational movement which is transmitted via the first transmission means can be changed by an activation of the phase adjusting member to the rotational movement which is transmitted via the second transmission means.

For example, the first transmission means may be formed between the inner shafts and the phase actuator by means of a respective gear pair having a first gear and a second gear. The first gear can be rigidly connected, for example, with the rotor of the phase actuator and it can be provided two further gears, which rest on the respective inner shafts of the camshaft. Consequently, the two gears engage on the inner shafts at different circumferential positions in the gear on the phase adjusting member, so that via the teeth, the two inner shafts rotatably and synchronously connected in phase with each other.

With further advantage, the second transmission means may be formed between one of the outer shafts and the phase actuator by means of a gear pair having a first gear and a second gear. The first gear may be connected, for example, with the stator of the phase actuator, and the second gear is seated on the outer shaft of one of the two camshafts. In particular, a further second toothed wheel can also rest on the further outer shaft, which likewise engages with the first toothed wheel on the phase adjusting member. It may be sufficient that only one outer shaft is driven by the drive means with the crankshaft of the internal combustion engine.

The adjusting axis of the phase actuator can form a triangular arrangement with the shaft axes of the camshafts. Furthermore, there is the possibility that the adjusting axis lies in the same plane as the shaft axes of the camshafts. In a triangular arrangement, however, the advantage can be used that the camshaft can be arranged with a smaller distance from each other, without the diameter of the phase actuator affects the distance between the two camshafts.

PREFERRED EMBODIMENT OF THE INVENTION

Further, measures improving the invention will be described in more detail below together with the description of a preferred embodiment of the invention of the single figure. It shows the

Figure is a schematic view of a valve train for actuating gas exchange valves of an internal combustion engine with two adjustable camshafts, constructed according to the DOHC principle.

The figure shows a schematic view of a valve train 1 for actuating gas exchange valves of an internal combustion engine with a first camshaft 10 that are in a first shaft axis 11 is rotatably received and with a second camshaft 20 that are in a second shaft axis 21 is recorded rotatable. The two camshafts 10 . 20 can be accommodated together in a cylinder head of an internal combustion engine or in a hood module.

The embodiment shows the two camshafts 10 and 20 as adjustable camshafts, and the first camshaft 10 has an outer shaft 12 and an inner shaft 13 on, and the inner shaft 13 is in the outer shaft 12 rotatably mounted. The second camshaft 20 has an outer shaft 22 and an inner shaft 23 on, with the inner shaft 23 also rotatable in the outer shaft 22 is stored.

On the two outside waves 12 . 22 are fixed cams 14 . 24 applied, the torsionally rigid with the external waves 12 . 22 are connected. Furthermore, on the outside of the outer shafts 12 . 22 recliner 15 . 25 rotatably received, with the inner shafts 13 . 23 are rotationally connected. Is the phase angle of the internal waves 13 . 23 to the phase position of the external waves 12 . 22 twisted, so twist the adjustment cam 15 . 25 relative to the festival cams 14 . 24 around the shaft axes 11 . 21 ,

The two external waves 12 . 22 are common about a drive means 2 driven, for example, a chain or a toothed belt, and on the outer shaft 12 the first adjustable camshaft 10 is a drive wheel 4.1 Applied, and on the outside 22 the second adjustable camshaft 20 is another drive wheel 4.2 applied. The drive means 2 drives over the drive wheels 4.1 and 4.2 both external waves 12 and 22 together with a mutually equal phase position. The drive is via a crankshaft 3 , which is indicated only schematically.

Between the two camshafts 10 and 20 is a phase actuator 30 arranged, and the phase actuator 30 has a positioning axis 33 which is spaced apart from the first shaft axis 11 the first camshaft 10 and to the second shaft axis 21 the second camshaft 20 ,

The phase actuator 30 is via a first transmission means 34 with the inner shafts 13 . 23 the camshafts 10 . 20 connected, the outer shaft 22 the second camshaft 20 via a further, second transmission means 35 with the phase actuator 30 connected is. The first transmission medium 34 is formed by a first gear 34.1 that with a rotor 32 of the phase actuator 30 connected is. Furthermore, the first transmission means 34 two second gears 34.2 on, and the second gears 34.2 sit on the respective shaft axes 11 and 21 the camshafts 10 and 20 , and are with the inner shafts 13 and 23 connected. Through the engagement of the two second gears 34.2 on the inner shafts 13 . 23 with the first gear 34.1 are the two inner shafts 13 . 23 blindfolded connected.

The second transmission means 35 has a first gear 35.1 on, that with the stator 31 of the phase actuator 30 connected is. The second transmission means 35 also has a second gear 35.2 on, with the outside wave 22 the second camshaft 20 is connected, wherein the connection is shown only by way of example and the second gear 35.2 the second transmission means 35 can work in the same way with the outer shaft 12 the first camshaft 10 be connected.

By activation of the phase actuator 30 can the inner shafts 13 . 23 the two camshafts 10 . 20 be changed in their phase position to the phase of the external waves 12 . 22 so that the respective adjustment cams 15 . 25 in their phase relation relative to the fixed cams 14 . 24 around the shaft axes 11 . 21 can be adjusted. As a result, with a separately arranged phase actuator 30 both adjustable camshafts 10 . 20 be adjusted.

The embodiment shows a coupling of the first transmission means 34 with the rotor 32 of the phaser 30 , in the same way also a coupling with the stator 31 is possible. The second transmission means 35 may differ from the front of the representation in connection with the stator 31 , also with the rotor 32 be connected.

The invention enables activation of the phase actuator 30 in a particularly simple manner, since the accessibility in particular for fluid guides to the phase actuator 30 is simplified. Furthermore, the camshafts 10 . 20 only gears 34.2 and 35.2 on, for example, in one piece with the inner shaft 13 . 23 and with the outside wave 22 are connected. Due to the separated structure of the phase actuator 30 separated from the camshafts 10 . 20 Consequently, there is a simple construction of a valve drive, wherein in particular in the axial direction, that is, in the structural extension along the shaft axes 11 . 21 , the valve drive 1 can be made small construction. The limited space requirement arises in particular by the fact that a space can be exploited for the arrangement of the phase actuator 30 that is between the two camshafts 10 . 20 located.

The invention is not limited in its execution to the above-mentioned preferred embodiment. Rather, a number of variants is conceivable, which makes use of the illustrated solution even with fundamentally different types of use. All of the claims, the description or the drawings resulting features and / or advantages, including structural details or spatial arrangements may be essential to the invention both in itself and in various combinations.

LIST OF REFERENCE NUMBERS

1

 valve train

2

 drive means

3

 crankshaft

4.1

 drive wheel

4.2

 drive wheel

10

 first adjustable camshaft

11

 first shaft axis

12

 outer shaft

13

 inner shaft

14

 fixed cams

15

 recliner

20

 second adjustable camshaft

21

 first shaft axis

22

 outer shaft

23

 inner shaft

24

 fixed cams

25

 recliner

30

 Phase actuator

31

 stator

32

 rotor

33

 adjusting axis

34

 first transmission means

34.1

 first gear

34.2

 second gear

35

 second transmission means

35.1

 first gear

35.2

 second gear

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006049243 A1 [0002]

Claims (11)

Valve train ( 1 ) for actuating gas exchange valves of an internal combustion engine with - a first camshaft ( 10 ), which are in a first shaft axis ( 11 ) is rotatably received and with - a second camshaft ( 20 ), which are in a second shaft axis ( 21 ) is rotatably received, - wherein at least one of the camshafts ( 10 . 20 ) as an adjustable camshaft ( 10 . 20 ) is executed and an outer shaft ( 12 . 22 ), in which an inner shaft ( 13 . 23 ) is rotatably received, - wherein at least one of the camshafts ( 10 . 20 ) via a drive means ( 2 ) with a crankshaft ( 3 ) is drivingly connected to the internal combustion engine, and - wherein a phase actuator ( 30 ) is provided, with the at least one inner shaft ( 13 . 23 ) in its phase position relative to the phase position of at least one outer wave ( 12 . 22 ) of the camshaft ( 10 . 20 ) is variable, characterized in that the phase actuator ( 30 ) one to both shaft axes ( 11 . 21 ) spaced arrangement. Valve train ( 1 ) according to claim 1, characterized in that the phase actuator ( 30 ) a stator ( 31 ) and a rotor ( 32 ), wherein the stator ( 31 ) and the rotor ( 32 ) in a common control axis ( 33 ) are rotatably arranged, and wherein the adjusting axis ( 33 ) spaced parallel to the shaft axes ( 11 . 21 ) of the camshafts ( 10 . 20 ) is arranged. Valve train ( 1 ) according to claim 1 or 2, characterized in that the phase actuator ( 30 ) via a first transmission means ( 34 ) with the at least one inner shaft ( 13 . 23 ) is operatively connected. Valve train ( 1 ) according to one of claims 1 to 3, characterized in that both camshafts ( 10 . 20 ) as adjustable camshafts ( 10 . 20 ) are executed and a respective outer shaft ( 12 . 22 ) and a respective inner shaft ( 13 . 23 ), both inner shafts ( 13 . 23 ) via the first transmission means ( 34 ) are mutually immutable in phase with each other. Valve train ( 1 ) according to one of the preceding claims, characterized in that the outer shaft ( 12 ) of the first camshaft ( 10 ) and the outer shaft ( 22 ) of the second camshaft ( 20 ) with the drive means ( 2 ) from the crankshaft ( 3 ) of the internal combustion engine are driven together. Valve train ( 1 ) according to one of claims 3 to 5, characterized in that the first transmission means ( 34 ) with the rotor ( 32 ) of the phase actuator ( 30 ) connected is. Valve train ( 1 ) according to any one of the preceding claims, characterized in that the phase actuator ( 30 ) via a second transmission means ( 35 ) with the outer shaft ( 12 . 22 ) one of the camshafts ( 10 . 20 ) is operatively connected. Valve train ( 1 ) according to claim 7, characterized in that the second transmission means ( 35 ) with the stator ( 31 ) of the phase actuator ( 30 ) connected is. Valve train ( 1 ) according to one of claims 3 to 8, characterized in that the first transmission means ( 34 ) between the inner shafts ( 13 . 23 ) and the phase actuator ( 30 ) by means of a respective gear pairing with a first gear ( 34.1 ) and with a second gear ( 34.2 ) is formed. Valve train ( 1 ) according to one of claims 7 to 9, characterized in that the second transmission means ( 35 ) between one of the outer waves ( 12 . 22 ) and the phase actuator ( 30 ) by means of a gear pairing with a first gear ( 35.1 ) and with a second gear ( 35.2 ) is formed. Valve train ( 1 ) according to one of the preceding claims, characterized in that the adjusting axis ( 33 ) of the phase actuator ( 30 ) with the shaft axes ( 11 . 21 ) of the camshafts ( 10 . 20 ) forms a triangle arrangement.

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