DE102017103718A1 - Phase adjuster for a camshaft of an internal combustion engine - Google Patents

Abstract

There is provided a phase adjuster 36 for a camshaft 28 of an internal combustion engine, which has at least one drive wheel and a connection piece for the rotation-transmitting and in particular rotationally fixed connection with the camshaft 28. The phase adjuster 36 is characterized by a first actuator 40 and a second actuator 42, wherein the actuators 40, 42 are coupled to each other such that the adjustable by the individual actuators 40, 42 adjustment (relative to the same adjustment) are transmitted additively to the connector , As a result, a phase adjuster 36 having a comparatively large adjustment range for the camshaft 28 can be realized in a structurally advantageous manner.

Description

The invention relates to a phaser for a camshaft of an internal combustion engine and a combination of such phaser with a camshaft. The invention further relates to an internal combustion engine with a valve drive comprising such a combination as well as a motor vehicle having such an internal combustion engine.

The valve drive for a (reciprocating) internal combustion engine comprises at least one, regularly two intake and exhaust valves for each combustion chamber of the internal combustion engine. These intake and exhaust valves, also referred to as gas exchange valves, are actuated by camshafts in almost all internal combustion engines, with two camshafts being used regularly in internal combustion engines having more than two gas exchange valves per combustion chamber. In many cases, the arrangement of these camshafts is such that one of them controls all intake valves and the other all exhaust valves.

It is known, to improve the operating behavior of an internal combustion engine, the valve timing of the gas exchange valves at least partially, if necessary, to change that the phase angle of the actuating camshafts are adjusted. For this purpose, the respective camshaft by means of a phaser relative to a drive wheel, via which it is driven in rotation, rotated by a defined displacement, whereby the valve timing of the thus controlled gas exchange valves in the direction of "early" or "late" are adjusted.

Also known are internal combustion engines in which the camshafts each control both intake and exhaust valves. These are often referred to as "mixed camshafts". In principle, phasing of such a (simple) mixed camshaft results in a change in the valve timing of both the intake and exhaust valves actuated thereby in the same direction and with the same displacement angle. However, this is not advantageous in many cases. Rather, the valve timing of the intake and exhaust valves should be independently controllable. This can be achieved for mixed camshafts by forming them in the form of concentric double camshafts. These consist of an outer shaft and an inner shaft mounted inside the outer shaft, wherein both the inner and the outer shaft are provided with cams for the control of the intake and exhaust valves. The cams of the inner shaft protrude through openings in the outer shaft. By means of a phaser, which can rotate the inner and the outer shaft against each other, then there is the possibility to adjust the timing of the intake and / or exhaust valves independently.

Such a phaser is from the US 7,841,311 B2 known. This includes a drive wheel, which is driven by any drive means (gear, timing belt, timing chain) rotating from a crankshaft of an internal combustion engine. The rotation of the drive wheel is transmitted via two impellers to a double camshaft, wherein one of the impellers acts on the inner shaft and the other impeller on the outer shaft of the camshaft. The impellers are within limits rotatable within a likewise driven by the drive wheel housing, whereby a phase adjustment of the associated with the impellers inner and outer shafts relative to the drive wheel can be achieved. The adjustment of the two impellers within the housing takes place hydraulically and independently of each other, ie the phase adjustment of one shaft has no effect on the adjustability of the other shaft.

In the phaser according to the US 7,841,311 B2 forms each of the two individual plates, which are each formed of an impeller and a cooperating with this portion of the housing, a total of five pressure chambers, which are arranged distributed uniformly over the respective circumference of the individual and each of a wing of the associated impeller and a radial are limited inwardly projecting housing portion. Due to this construction, the maximum displacement angle, which is adjustable by means of each of the individual actuators for the associated camshaft, limited because only the circumference of 360 ° is available for the integration of the pressure chambers in the individual actuator. In the case of currently available phasors, which in principle correspond to those according to the US 7,841,311 B2 The maximum adjustment angle is usually 50 ° or less.

The DE 10 2011 116 30 A1 discloses a phaser with two individual actuators, which are each provided for the adjustment of the phase angle of a camshaft associated therewith, wherein the adjustment of the individual actuator is to be made in dependence on each other.

The invention had the object of specifying a phaser, which allows the simplest possible way the realization of a relatively large displacement angle (phase angle) for the camshaft.

This object is achieved by a phaser according to the patent claim 1. A combination of such a phaser and a Camshaft, an internal combustion engine with such a combination and a motor vehicle with such an internal combustion engine are subject matter of claims 8 to 10. Advantageous embodiments of the phaser according to the invention and thus the combination of the invention, the internal combustion engine according to the invention and the motor vehicle according to the invention are objects of the further claims and / or result from the following description of the invention.

The invention is based on the idea to use at least two (single) actuator together for adjusting a single camshaft and to additively couple to each other with respect to the respective achievable adjustment angle, whereby a total of at least almost doubled adjustment angle for the camshaft can be realized.

Accordingly, a phaser for a camshaft of an internal combustion engine is provided which has at least one drive wheel and a connection piece for the rotation-transmitting and in particular rotationally fixed connection with the camshaft. The phase adjuster is characterized by a first actuator and a second actuator, wherein the actuators are coupled to each other in such a way that the adjustable by the individual actuator adjustment angle (relative to the same adjustment) are transmitted additively to the connector.

Such a phase adjuster can be realized structurally advantageously if an adjustment of the first actuator according to an adjustment direction results in a twisting of the connection piece and of the second actuator (in particular to the same extent) relative to the drive wheel in one direction of rotation and an adjustment of the second actuator in the same position ) Adjustment direction leads to a twisting of the connection piece in the (same) direction of rotation (without the first actuator being twisted counter to the direction of rotation).

For this purpose, preferably a rotatably connected to the drive wheel stator, a rotatably connected to the connector (possibly integrally) connected rotor of the second actuator and a coupling piece may be provided, wherein the stator, the rotor and the coupling piece are coupled together such that due to the adjustment of the the first actuator of the stator is not and the coupling piece is rotated relative to the drive wheel and as a result of the adjustment of the second actuator, the coupling piece is not and the rotor is rotated relative to the drive wheel.

Such a coupling can be attained particularly advantageously if it is provided that the stator with the coupling piece and the coupling piece with the rotor each delimit at least one pressure chamber whose sizes are determined by the supply and removal of a fluid (gas or liquid), in particular a liquid. are changeable.

Furthermore preferably, it can then be provided that the stator with the coupling piece and the coupling piece with the rotor each delimit at least a first pressure chamber and at least one second pressure chamber, wherein the first pressure chambers are provided for connection to an external fluid supply and the second pressure chambers fluid-conducting each other are connected. The (or respectively one) first pressure chamber and the (a) second pressure chamber of each actuator can be separated from each other in particular by means of the coupling piece. As a result, a particularly compact coupling of the actuator can be achieved in an advantageous manner by flowing into the first (n) pressure chamber (s) of the actuator, for example, the first actuator, inflowing fluid to an enlargement of this first pressure chamber (s), whereby the this second pressure chamber (s) of the same actuator are reduced to the same extent by the second pressure chamber (s) of the same actuator, the fluid contained in this second pressure chamber (s) entering the (respectively) second fluidically connected second pressure chamber (n) of the other (second) actuator overflowed, whereby these second (n) pressure chamber (s) (s) are increased, resulting in a reduction of the / the first pressure chamber (s) of this other (second) actuator due to the separation by means of the coupling piece, wherein fluid contained in said first pressure chamber (s) is removed.

In order to be able to realize a sufficiently high adjusting moment of the phaser even with a relatively low fluid pressure, it can preferably be provided that the stator with the coupling piece and the coupling piece with the rotor each delimit three, four, five or more pressure chambers. If both first and second pressure chambers are provided for the actuators, respectively three, four, five or more first pressure chambers and three, four, five or more second pressure chambers should be provided. The resulting from such a relatively high number of trained in the writers pressure chambers resulting limitation of the maximum achievable for the individual adjuster adjustment angle is unproblematic as a result of the total in terms of the camshaft achievable adjustment angle coupling of at least two actuators. In this respect, it may be provided, for example, that the first actuator and / or the second actuator individually has a maximum displacement angle of only about 50 °.

A combination according to the invention comprises, in addition to an inventive Phase adjuster at least one rotationally transmitting and in particular rotationally fixed to the connecting piece of the phaser connected camshaft.

An internal combustion engine according to the invention comprises a valve drive with at least one such combination of phaser according to the invention and associated camshaft.

An inventive motor vehicle comprises such an internal combustion engine according to the invention, wherein the internal combustion engine can be provided in particular for generating a traction drive power for the motor vehicle. The motor vehicle may in particular be a wheel-based motor vehicle (preferably a car or a truck). Use in other motor vehicles, such as rail vehicles or ships, is also possible.

• 1: eine erfindungsgemäße Brennkraftmaschine;
• 2: eine erfindungsgemäße Kombination eines Phasenstellers und einer Nockenwelle;
• 3: den Phasensteller gemäß der 2 ohne Gehäuse und in einer ersten Endstellung;
• 4: den Phasensteller gemäß der 3 in einer mittleren Stellung;
• 5: den Phasensteller gemäß den 2 und 3 kurz vor dem Erreichen einer zweiten Endstellung; und
• 6: ein erfindungsgemäßes Kraftfahrzeug.

The invention will be explained in more detail with reference to an embodiment shown in the drawings. In the drawings shows, in a simplified representation:

• 1 an internal combustion engine according to the invention;
• 2 a combination according to the invention of a phaser and a camshaft;
• 3 : the phaser according to the 2 without housing and in a first end position;
• 4 : the phaser according to the 3 in a middle position;
• 5 : the phaser according to the 2 and 3 shortly before reaching a second end position; and
• 6 : a motor vehicle according to the invention.

The 1 shows in simplified representation an internal combustion engine 10 according to the invention. This includes an internal combustion engine 12 , which is formed in the present embodiment as a four-cylinder (series) reciprocating engine and can be operated for example according to the gasoline or diesel principle. These are in a cylinder crankcase 14 cylinder 16 formed in which pistons 18 are guided longitudinally axially movable. A movement of the pistons caused by combustion processes 18 is over connecting rod 20 on one in the cylinder crankcase 14 rotatably mounted crankshaft 22 transfer. This rotation of the crankshaft 22 can on driven wheels of a motor vehicle (see. 6 ) be transmitted. The internal combustion engine 10 can thus serve to generate the traction drive power for the motor vehicle.

A rotation of the crankshaft 22 is also using a tax drive 24 , which may be formed in the form of a toothed belt or chain drive, for example, on a in a cylinder head housing 26 of the internal combustion engine 12 rotatably mounted first camshaft 28 transfer. At this first camshaft 28 it may be an intake camshaft, by means of intake valves 30 be actuated via the fresh gas in combustion chambers, by the cylinders 16 , the piston 18 as well as the cylinder head housing 26 are limited, can be introduced controlled. In this case, this fresh gas is burned with fuel injected directly into the combustion chambers to the through the crankshaft 22 controlled movement of the pistons 18 inside the cylinder 16 to effect.

By means of a gear transmission 32 (with a ratio of one) becomes a rotational movement of the first camshaft 32 on a second camshaft (not visible), which is then an exhaust camshaft of the engine 10 can act, transfer. Accordingly, this second camshaft actuates exhaust valves (not visible), by means of which exhaust gas, which was produced during combustion of the fuel fresh-gas mixtures in the combustion chambers, can be removed in a controlled manner.

By means of a fuel pump (not shown) can injectors 34 of the internal combustion engine 12 Fuel from a fuel tank (not shown) of the internal combustion engine 10 fed. be by means of injectors 34 The fuel can then be injected under relatively high pressure and at predetermined times in the combustion chambers.

Both the first camshaft 28 as well as the second camshaft can each have a phaser 36 be associated with one or both of these Phasensteller 36 can be configured according to the invention.

Such an inventive phaser is in combination with an associated camshaft in the 2 to 5 shown.

This includes next to a drive wheel 38 (see. 1 ) and a connector (not visible), which serves for the rotationally transmitting connection with one of the camshafts, a first actuator 40 and a second actuator 42 , which according to the invention are coupled to each other in such a way that by the individual controller 40 . 42 adjustable adjustment angle is additive to the connector and thus transferred to the associated camshaft.

In the exemplary use of the in the 2 to 5 phase adjuster 36 shown for adjusting the phase angle of the first camshaft 28 the internal combustion engine according to the 1 can be provided that the drive wheel rotatably with a stator 44 of the first author 40 connected is. This stator 44 of the first author 40 includes, optionally in a one-piece design, an annular boundary wall 46 , from which a ring-cylindrical connecting piece 48 in the direction of the cam (not shown) comprising portion of the camshaft 28 extends. This connection piece 48 can the non-rotatable connection with a drive wheel 38 , For example, the upper gear of the timing gear 24 the internal combustion engine according to the 1 , serve. From the concerning the connecting piece 48 opposite side of the boundary wall 46 extend in parallel with respect to the longitudinal or rotational axis 50 the camshaft 28 extending alignments a total of four dividers 52 , on the inside on an annular cylindrical bottom part of a coupling piece 54 are movably mounted. The stator 44 and the coupling piece 54 are rotatable on a portion of the camshaft 28 stored.

The coupling piece 54 includes, optionally in a one-piece design, adjacent to the bottom part 56 an annular boundary wall 58 as well as four of the boundary wall 58 in the direction of the stator 44 extending dividers 60 which are also parallel to the axis of rotation 50 the camshaft 28 have extending orientations. The free ends of the dividers 52 of the stator 44 lie sealingly with respect to the stator 44 proximal side of the boundary wall 58 of the coupling piece 54 on and the free ends of these dividers 60 as well as the bottom part 56 of the coupling piece 54 lie sealingly with respect to the coupling piece 56 proximal side of the boundary wall 46 of the stator 44 at. In combination with the in the 2 illustrated housing 62 of the phaser 36 limit the stator 44 and the coupling piece 36 in each case four first pressure chambers 64 and four second pressure chambers 66 arranged in an alternating arrangement over the circumference (with respect to the axis of rotation 50 the camshaft 28 ) of the first author 40 are arranged distributed. Accordingly, there are in each case between two circumferentially adjacent separating webs 52 of the stator 52 a first pressure chamber 64 and a second pressure chambers 66 by means of a divider 60 of the coupling piece 54 are separated from each other.

Due to the rotatability of the coupling piece 54 relative to the stator 44 are the sizes (volumes) of the pressure chambers 64 . 66 changeable, wherein an enlargement or reduction of the first pressure chambers 64 to a proportional, respectively opposite change in the sizes of the second pressure chambers 66 leads.

The second stopper 42 includes next to the coupling piece 54 a rotor 68 , where the coupling piece 54 and the rotor 68 in a similar way as this for the coupling piece 54 and the stator 44 is provided, interlocking and rotatable are combined. This includes the coupling piece 54 also on the rotor 68 facing side of its boundary wall 58 four dividers 60 and a ring cylindrical bottom part 56 , There are two each on different sides of the boundary wall 58 arranged dividers 60 of the coupling piece 54 arranged in alignment. The free ends of the rotor 68 facing dividers 60 and the associated floor part 56 of the coupling piece 54 lie sealingly on an annular boundary wall 70 of the rotor 68 at. At the same time, the free ends of four (parallel with respect to the axis of rotation 50 the camshaft 28 aligned) separating webs 72 of the rotor 68 sealing on the side facing the boundary wall 56 of the coupling piece 54 on, so that the coupling piece 54 and the rotor 68 in combination with the housing 62 of the phaser 36 also each four first pressure chambers 64 and four second pressure chambers 66 of the second phaser 42 limit, each between two adjacent dividers 72 of the rotor 68 a first pressure chamber 64 and a second pressure chamber 66 are arranged, by means of a divider 60 of the coupling piece 54 are separated from each other.

Alternatively, it is also possible that the bottom parts described as components of the coupling piece 54 56 Part of the stator 44 and / or the rotor 68 are on which the the respective bottom part 56 assigned dividers 60 of the coupling piece 54 are movably guided.

In all first pressure chambers 64 of the first author 40 and the second author 42 opens at the smallest possible distance (in the circumferential direction) to each of the stator 44 or the rotor 54 associated divider 52 . 72 one in the boundary wall 46 . 70 of the stator 44 or the rotor 68 integrated connection opening 74 about which the first pressure chambers 64 to an external fluid supply 76 (see. 1 ), which is a fluid reservoir 78 as well as a conveying device which can be controlled with respect to the delivery rate 80 may include, is connectable. Furthermore, in the boundary wall 58 of the coupling piece 54 a total of four overflow openings 82 integrated, through each of which a second pressure chamber 66 of the first author 40 and a second pressure chamber 66 of the second author 42 fluidly connected. Here are the overflow 82 also in the smallest possible distance (in the circumferential direction) to the respective second pressure chambers 66 limiting divider 60 of the coupling piece 54 arranged.

For a rotation of the camshaft 28 (relative to the drive wheel 38 ) of, for example, in the 3 end position shown in one of the 4 and 5 shown positions is provided by means of the fluid supply 76 a fluid (in particular a liquid, eg an oil) with a defined overpressure into the first pressure chambers 64 of the first author 40 introduce, which creates these first pressure chambers 64 enlarge. This results in a proportional reduction of that of the first actuator 40 trained second pressure chambers 66 , wherein in these second pressure chambers 66 of the first author 40 contained fluid via the overflow openings 82 in each case with these fluidly connected second pressure chambers 66 of the second author 42 overflowed, causing these second pressure chambers 66 of the second author 42 , proportional to the reduction of the second pressure chambers 66 of the first author 40 , enlarge. This enlargement of the second pressure chambers 66 of the second author 42 in turn leads to a proportional reduction of the first pressure chambers 64 of the second author 42 , wherein in these first pressure chambers 64 of the second author 42 existing fluid is discharged via the associated connection openings 74.

This functionality of the phaser according to the invention 36 is in total with a maximum achievable rotation of the rotor 68 and the one with the rotor 68 rotatably connected camshaft 28 relative to the stator 44 and thus relative to the drive wheel 38 connected, the addition of the two maximum achievable adjustment of the two individual actuator 40 . 42 corresponds to the maximum achievable adjustment angle of the two individual actuator 40 . 42 by the angle of the largest possible (circular segment) sliding movement of the dividers 60 of the coupling piece 54 each within two adjacent dividers 52 . 72 of the stator 44 and the rotor 68 is limited. Overall, thus, for the camshaft 28 an almost twice as large adjustment angle for the assigned camshaft 28 be realized, as by the use of a single actuator with a structure according to the two writers 40 . 42 the phaser according to the invention 36 it is possible. This is due to the fluidic coupling of the two controllers 40 . 42 for the coupled adjustment of the two controllers 40 . 42 required flow rate of fluid not larger than they are for the adjustment of a single actuator 40 . 42 would.

In the described coupling of the two controllers 40 . 42 serves the coupling piece 54 as a rotor for the first steller 40 effected adjustment and at the same time as a stator for by the second actuator 42 effected adjustment, wherein the coupling piece 54 not resting, but as that element of the second actuator 42 acts against which the rotor 68 rotates.

For turning back the camshaft 28 starting from one of the in the 4 and 5 represented positions in the direction of in the 3 shown end position can be provided by switching the fluid supply 76 why they have a corresponding changeover valve 84 may have, the first pressure chambers 64 of the second author 42 to pressurize the fluid, resulting in an enlargement of these first pressure chambers 64 of the second author 42 and, due to the described fluidic coupling of the two actuators 40 . 42 , resulting in a reduction of the first pressure chambers 64 of the first author 40 leads, wherein in these first pressure chambers 64 of the first author 40 contained fluid partially via the associated connection openings 74 is dissipated.

Additionally or alternatively, it may also be provided that a reverse rotation of the camshaft by means of a spring element, which has been increasingly biased in the previous twisting, is effected.

Alternatively to the basis of the 2 to 5 described use and design of the phaser 36 can also be provided, a drive wheel with the previously designated as a rotor component 68 rotatably connecting, whereby this serves as a stator of the phaser, while the previously designated as a stator component 44 serves as a rotor which is provided for the non-rotatable or at least rotationally transmitted connection with a camshaft. This camshaft may, for example, be an outer shaft of a double camshaft, which is rotatably mounted within limits on an inner shaft, said inner shaft preferably with the now used as a stator component 68 can be connected rotatably.

Additionally or alternatively, it can also be provided that with the now used as a rotor component 44 a gear of the gear transmission 32 the internal combustion engine 10 according to the 1 is connected, whereby this acting as a rotor component 44 rotationally transmitting with the second camshaft of the internal combustion engine 10 would be connected, so that by an adjustment of the phaser 36 the phase angle of the second camshaft by means of the first camshaft 28 assigned and as a drive wheel 38 a gear wheel of the timing drive 24 using phase phasor 36 can be realized.

LIST OF REFERENCE NUMBERS

10

Internal combustion engine

12

internal combustion engine

14

cylinder crankcase

16

cylinder

18

piston

20

pleuel

22

crankshaft

24

Timing

26

Cylinder head housing

28

first camshaft

30

intake valve

32

gear transmission

34

injector

36

phaser

38

drive wheel

40

first starter

42

second adjuster

44

stator

46

Boundary wall of the stator

48

Connecting piece of the stator

50

Longitudinal and rotational axis of the camshaft

52

Divider of the stator

54

coupling

56

Bottom part of the coupling piece

58

Boundary wall of the coupling piece

60

Divider of the coupling piece

62

Housing of the phaser

64

first pressure chamber

66

second pressure chamber

68

rotor

70

Boundary wall of the rotor

72

Divider of the rotor

74

port opening

76

fluid supply

78

fluid reservoir

80

conveyor

82

overflow

84

switching valve

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

• US 7841311 B2 [0005, 0006]
• DE 10201111630 A1 [0007]

Claims (10)

Phase adjuster (36) for a camshaft (28) of an internal combustion engine (10) with a drive wheel (38) and a connection piece for the rotationally transmitting connection to the camshaft (28), characterized by a first actuator (40) and a second actuator (40), wherein the actuators (40, 42) are coupled to one another in such a way that the adjusting angles which can be set by the individual actuators (40, 42) are transmitted additively to the connection piece. Phase adjuster (36) according to Claim 1 , characterized in that an adjustment of the first actuator (40) according to an adjustment direction to a rotation of the connecting piece and the second actuator (42) relative to the drive wheel (38) in a rotational direction and an adjustment of the second actuator (42) in the adjustment leads to a rotation of the connecting piece relative to the drive wheel (38) in the direction of rotation. Phase adjuster (36) according to Claim 2 characterized by a rotatably connected to the drive wheel (38) connected to the stator (44), a rotatably connected to the connector connected rotor (68) and a coupling piece (54), wherein the stator (44), the rotor (68) and the coupling piece ( 54) are coupled together such that due to the adjustment of the first actuator (40) the stator (44) is not and the coupling piece (54) is rotated relative to the drive wheel (38) and due to the adjustment of the second actuator (42) the coupling piece (54) and the rotor (68) is rotated relative to the drive wheel (38). Phase adjuster (36) according to Claim 3 , characterized in that the stator (44) with the coupling piece (54) and the coupling piece (54) with the rotor (68) each at least one pressure chamber (64, 66) limited, the sizes of which by the supply and discharge of a fluid variable are. Phase adjuster (36) according to Claim 4 , characterized in that the stator (44) with the coupling piece (54) and the coupling piece (54) with the rotor (68) each at least a first pressure chamber (64) and at least one second pressure chamber (66) limited, wherein the first pressure chambers (64) with a fluid supply (76) are connectable and the second pressure chambers (66) are fluid-conductively connected to each other. Phase adjuster (36) according to Claim 4 , characterized in that the stator (44) with the coupling piece (54) and the coupling piece (54) with the rotor (68) in each case three, four, five or more pressure chambers (64, 66) limited. Phase adjuster (36) according to Claim 5 , characterized in that the stator (44) with the coupling piece (54) and the coupling piece (54) with the rotor (68) in each case three, four, five or more first pressure chambers (64) and three, four, five or more second Pressure chambers (66) limited. Combination of a phaser (36) according to one of the preceding claims and a camshaft (28) connected in rotation with the connecting piece of the phaser (36). Internal combustion engine (10) with at least one combination according to Claim 8 comprehensive valvetrain. Motor vehicle with an internal combustion engine (10) according to Claim 9 ,

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