DE102008011116A1 - Camshaft adjuster i.e. blade cell adjuster, for internal-combustion engine of motor vehicle, has set of casings arranged in such manner that three separate axial pressure medium lines are formed - Google Patents

Abstract

The adjuster (1) has a stator (2) in drive connection with a crankshaft. A rotor (3) is pivotably connected with a cam shaft (14) at a front side, where the rotor is adjustably mounted on the stator. A cavity is fluidically connected with a set of radial pressure medium lines in the rotor. A control member has two casings that are concentrically surrounded to each other, where the control member is made of plastics. The casings are arranged in such a manner that three separate axial pressure medium lines are formed.

Description

Field of the invention

The Invention is in the technical field of internal combustion engines and relates to a camshaft adjuster for an internal combustion engine according to the preamble of claim 1.

State of the art

In Internal combustion engines are mechanically actuated of gas exchange valves typically via one of a Crankshaft driven camshaft, with over arrangement and shape of the cam opening and closing times the gas exchange valves are selectively adjustable. Is applied to the opening and closing times of the gas exchange valves in dependence the current operating state of the internal combustion engine influence taken, a number of beneficial effects can be achieved, such as a reduction in pollutant emissions, a reduction fuel consumption and an increase in efficiency, Maximum torque and maximum power of the internal combustion engine.

A change the opening and closing times of the gas exchange valves can by changing the relative rotational position (phase angle) be achieved between cam and crankshaft, for what purpose in modern motor vehicles special devices, so-called Camshaft adjuster, are used.

Generally include camshaft adjuster one with the crankshaft in drive connection stationary drive part, a camshaft fixed output part and a switched between input and output part actuator, which transmits the torque from the drive part to the output part and a fixation and adjustment of the relative rotational position between allows these two.

at a hydraulic Flügelzellenversteller is the drive part by an outer rotor driven by the crankshaft ("Stator") and the output part through one with the camshaft rotatably connected inner rotor ("rotor") shaped. The rotor is concentric with the stator in a central cavity of the stator rotatably mounted. In a usual design is the rotor end face rotatably connected to the camshaft.

typical Way distributed in the stator circumferentially arranged work spaces formed, in each of which one connected to the rotor radial Wing extends, making each working space in two Substantially pressure-tight pressure chambers is shared. Related to the drive direction of the stator divides each wing Working space in a leading pressure chamber and a trailing pressure chamber. By targeted pressurization of the pressure chambers of a pressure chamber pair Can the wings within the work spaces be pivoted, which causes over the rotatably connected to the camshaft rotor a change the relative rotational position (phase angle) between cam and crankshaft is effected. A limitation of the adjustment angle between the rotor and stator is made by attacking the wings against the radial walls of workrooms or by special facilities for limiting the adjustment angle.

A Control of the Flügelzellenverstellers done by a electronic control device based on electronic recorded characteristics of the internal combustion engine, such as speed and load, the inflow and outflow of pressure medium to or from the individual Pressure chambers via, for example, as a proportional valve trained control valve regulates.

at an actuation of the gas exchange valves must the cams in the area of their starting ramp that of a valve spring held in the closed position gas exchange valve against the Open spring force, which increases the drive torque is, and are in the range of their deceleration ramp of the spring force applied, whereby the drive torque is reduced. The hereby Alternating moments generated are on the non-rotatably connected to the camshaft Rotor transferred. In the case of insufficient pressure medium supply, like this during the starting phase of the internal combustion engine or idle, the transferred carry Alternating moments cause the wings within the work spaces beat back and forth, which promoted the wear and causes unwanted noise. In addition, the phase angle between crankshaft and camshaft fluctuates greatly, so that the internal combustion engine does not start or runs restless.

To avoid this problem, hydraulic Flügelzellenversteller are usually equipped with a locking device for non-rotatable locking of the stator and rotor in a - designated as the base position - selectable phase position. As a base position, a thermodynamically favorable phase position of the camshaft is selected for the start of the internal combustion engine, which depends on the specific design of the internal combustion engine. This is usually a so-called early, late or middle position. Based on the drive direction of the stator or camshaft corresponds to the late position of a final rotational position of the rotor in the direction of traversing (volumes of the leading pressure chambers are maximum), the early position of a final rotational position of the rotor in the forward direction (volumes of trailing pressure chambers are maximum) and the center position of a phase position, the is at least approximately in the middle between the early and late position.

Flügelzellenversteller are well known as such and for example in the publications DE 20 2005 008 264 U1 . EP 1 596 040 A2 . DE 10 2005 013 141 A1 and DE 199 08 934 A1 the applicant described in detail.

The Locking device comprises in a typical embodiment at least one axial locking pin received in the rotor, which is urged by a spring in the axial direction of its inclusion is and positively engage in a locking link can, which encapsulate in an axial side plate of a rotor Housing is shaped. For a release is the locking pin is applied to the front side with pressure medium and can pushed back in this way in its inclusion in the rotor become.

Becomes is selected as the basic position, the early position is the locking gate usually with the pressure chambers, for example, with the leading pressure chambers, fluidically connected. For a lock in the middle position is however, usually a separate pressure medium supply required around the locking pin independent of the pressure chambers to act hydraulically.

is the camshaft adjuster is connected to the front side of the camshaft, there is a supply of the pressure chambers and the locking link with pressure medium so far typical way of axial pressure medium lines in the camshaft, with pressure medium lines in the rotor and stator are fluidically connected.

This However, it is associated with considerable manufacturing disadvantages, because the axial pressure medium lines in the camshaft a high processing cost require and, as in the practice of industrial mass production has often been contaminated with residual impurities that can not be safely removed despite washing, thereby improving the patency the axial pressure medium lines can be impaired. This is especially true when locking in center position, so that three separate axial pressure medium lines in the camshaft have to be shaped.

moreover axial pressure lines create positioning problems the camshaft adjuster, since the camshaft adjuster due to the required fluidic connection of the axial Pressure medium lines of the camshaft with the pressure medium lines The rotor must be positioned relatively accurately, which is high requirements for the required manufacturing tolerances brings with it.

In the German Offenlegungsschrift DE 10135146 A1 a generic device for relative rotation angle change of a camshaft is described, in which a control sleeve is provided, by which on the one hand between the inside of the control sleeve and a central screw for fixing the device to the camshaft and on the other hand between the outside of the control sleeve and the hub of an impeller (rotor ) is formed in each case an axial oil passage.

adversely in the device shown there is in particular the fact that through the control sleeve only two axial oil flows separated from one another to the rotor, so that the device shown there for the rotation angle change not is usable when more than two separate axial oil flows are required, for example in a camshaft adjuster with center locking.

Object of the invention

In contrast, the object of the present invention is a generic camshaft adjuster to provide for an internal combustion engine, by which the disadvantage can be avoided.

Solution of the task

These and further objects are according to the proposal of the invention a camshaft adjuster with the characteristics of the independent Patent claim solved. Advantageous embodiments of Invention are indicated by the features of the subclaims.

One generic hydraulic camshaft adjuster includes a drive connected to a crankshaft Drive part and a camshaft fixed output part in concentric Arrangement is mounted rotatably adjustable to the drive part. Between Drive and driven part is a hydraulic actuator connected, which transmits the torque from the drive part to the output part and a fixation and adjustment of the relative rotational position (phase position) between these two possible. The phase angle of the output part is adjustable within a maximum rotation angle range. Of the Camshaft adjuster is via the output part with a Front side of the camshaft rotatably connected.

A generic camshaft adjuster further comprises a control comprising at least one axial sleeve, which in an at least partially formed by the camshaft Cavity is accommodated so that a plurality (at least two) of separate axial pressure medium lines are formed, which are fluidically connected to pressure medium lines in the output part.

Of the Inventive camshaft adjuster draws in a significant way characterized in that the control at least two sleeves at least partially concentrically surrounding each other which are arranged so that at least three separate axial pressure medium lines are formed. In the control is between two adjacent sleeves each have an axial pressure medium line shaped. According to the invention can thus in an advantageous Way to the production of axial pressure medium lines in the camshaft be waived, so that the aforementioned disadvantages avoided can be.

at an advantageous embodiment of the invention Camshaft adjuster are two mutually adjacent sleeves designed so that the radially outer sleeve has a shorter axial dimension than the radially inside located sleeve. This allows in an advantageous manner Way a simple fluidic connection of between two adjacent sleeves shaped axial pressure medium line with a shaped in the camshaft, in particular radial pressure medium line.

at a further advantageous embodiment of the invention Camshaft adjuster is the control in an axially stepped cavity taken, thereby easily an axial pressure medium line between the radially outermost sleeve and an inner peripheral wall of the cavity can be realized.

at a further advantageous embodiment of the invention Camshaft adjuster are the concentrically arranged sleeves through between the sleeves arranged support elements supported against each other, which is a simple technical Production of the control, in particular of a plastic Material, for example by injection molding, allows.

at a further advantageous embodiment of the invention Camshaft adjuster is the control in the form of a double sleeve with formed an outer sleeve surrounding an inner sleeve, whereby, for example, a hydraulic camshaft adjuster with central locking by three separate pressure medium flows is controllable. In a particularly simple technical realization the inner sleeve is not at its two end portions surrounded by the outer sleeve, leaving the between Inner and outer sleeve shaped axial pressure medium line in a simple manner with a pressure medium pump or a pressure medium tank fluidically connectable. The control is advantageous so housed in a stepped cavity, that a first axial Pressure medium line between the outer sleeve and an inner peripheral surface of the cavity, a second axial pressure medium line between inner and outer sleeve and a third axial pressure medium line within the inner sleeve are shaped. Furthermore, it may be advantageous if the control by a the output member with the camshaft rotatably connecting central bolt is fixed in the stepped cavity.

at a further advantageous embodiment of the invention Camshaft adjuster is the camshaft with at least three Provided radial pressure medium lines, which with the at least three separate axial pressure medium lines fluidically are connected. This embodiment allows a simple fluidic connection of the axial pressure medium lines with a pressure medium pump or pressure medium tank.

The Invention further extends to an internal combustion engine, equipped with at least one camshaft adjuster as described above is.

Brief description of the drawings

The Invention will now be described with reference to an embodiment with reference to the accompanying drawings is taken. Same or equivalent elements are in the Drawings with the same reference numbers. Show it:

1 in a schematic perspective partial sectional view of a Flügelzellenversteller invention;

2 in a further sectional view of the Flügelzellenversteller of 1 ;

3 in a further sectional view of the Flügelzellenversteller of 1 ;

4 in a further sectional view of an enlarged section of the Flügelzeilenverstellers of 1 in the area of the control;

5 in a perspective view of the control of the Flügelzellenverstellers of 1 ;

6 in a sectional view along line BB, the control of 5 ;

7 in a sectional view along line AA, the control of 5 ,

Detailed description the drawings

With reference to 1 to 7 is an embodiment of the invention a total with the reference number 1 designated hydraulic Flügelzellenversteller described.

Accordingly, the vane cell adjuster comprises 1 as a drive part one with a (not shown) crankshaft in drive connection standing external rotor or stator 2 and as a driven part in a central cavity of the stator 2 concentrically arranged inner rotor or rotor 3 , The stator 2 is on an inner peripheral surface 4 rotationally adjustable on the rotor 3 stored.

The inner peripheral surface 4 of the stator 2 is with a plurality of evenly distributed in the circumferential direction, radial recesses 5 provided in each one of the rotor 3 radially projecting wing 6 protrudes, causing each recess 5 in a pair of opposing pressure chambers 7 . 8th is shared. Based on a drive direction of the stator 2 , which corresponds here, for example, in an axial frontal view clockwise, runs a pressure chamber 7 ("Pressure chamber A") after, whereas the other pressure chamber 8th ("Pressure chamber B") precedes. A relative rotational position (phase angle) of rotor 3 to Stator 2 can in a selectable Verstellwinkelbereich, here, for example, from the two-sided attack of the wings 6 not shown radial side walls of the recesses 5 results, be adjusted. Similarly, a special device for limiting the maximum Verstellwinkeis be provided, for example, in a stator made of sheet metal 2 to avoid the wings 6 against the side walls of the recesses 5 beat.

The stator 2 is part of the rotor 3 pressure-tight encapsulating housing, the two axial side plates 9 . 10 includes, each with a pressure chambers 7 . 8th facing sealing surface are provided, which the pressure chambers 7 . 8th close pressure-tight in the axial direction. The stator 2 , the two side plates 9 . 10 and another pot-shaped housing section 11 are by several axial fixing screws 12 connected to a fixed unit. This unit is by means of a central screw 13 frontally on a camshaft 14 is attached. For this purpose, the two side plates 9 . 10 and the rotor 3 in the area of a hub section 15 provided with a central opening. The central screw 13 grips with her screw shaft 16 from the outside through this passage through and is by means of a threaded portion 17 with a complementary threaded axial threaded bore 18 the camshaft 5 screwed. For a mounting, the central screw 13 through a screw head 19 attached turning tool in the threaded hole 18 be screwed.

The camshaft 14 is with a first stepped bore 20 provided, which extends in the axial direction and into the threaded hole 18 passes. The first stepped bore 20 comprises four staggered arranged in the axial direction of the first to fourth ring stages 21 - 24 related to the central axis of rotation of the camshaft 14 are concentrically arranged and tapped 18 decreasing diameter, so that the first stepped bore 20 rejuvenated in this direction.

An axially extending second stepped bore 25 is in the hub section 15 of the rotor 3 shaped. The second stepped bore 25 comprises three staggered in the axial direction arranged first to third ring stages 26 - 28 related to the central axis of rotation of the camshaft 14 are arranged concentrically and, by the camshaft 14 directed away, having decreasing diameter, so that the second stepped bore 25 rejuvenated in this direction.

The first ring steps 21 . 26 , the second ring steps 22 . 27 and the third ring steps 23 . 28 the two stepped holes 20 . 25 each have the same diameter to each other. The two stepped holes 20 . 25 In this way, together they form a cavity, which can be subdivided, at least mentally, into several concentric step spaces. So is between the first two ring stages 21 . 26 an axially extending first step space 29 formed with a first diameter corresponding to the first two ring stages. Between the two second ring steps 22 . 27 is an axially extending second step space 30 with a second diameter corresponding to the two second annular steps, which diameter is smaller than the first diameter. Similarly, between the two third ring stages 23 . 28 an axially extending third step space 31 with a third diameter corresponding to the two third annular steps, which is smaller than the second diameter, shaped. According to the axially staggered arrangement of the first to third ring stages has the second step room 30 a larger axial dimension than the first step room 29 or the third step room 31 a larger axial dimension than the second step space 30 ,

In the of the two stepped holes 20 . 25 co-shaped cavity is formed in the form of a double-sleeve control 32 used. The control 32 includes a hollow cylindrical outer sleeve 33 , which is a hollow cylindrical inner sleeve 34 concentrically surrounds, with the outer sleeve 33 by means of three in the circumferential direction evenly distributed support struts 35 at the inner sleeve 34 supported. The outer sleeve 33 points opposite to the inner sleeve 34 a shortened axial dimension, so that the outer sleeve 33 exposed at its two end portions.

The (outer) diameter of the inner sleeve 34 corresponds to the radial dimension (diameter) of the third step space 31 , leaving an outer surface 36 the inner sleeve 34 at the two end portions of the inner sleeve 34 an inner peripheral surface 37 of the third step room 31 is applied. As the axial dimension of the inner sleeve 34 the axial distance between the two third ring stages 23 . 28 corresponds, the control can 32 through the central screw 13 passing through the inner sleeve 34 passed through, between the two third ring stages 23 . 28 axially braced and fixed in position.

Between the central screw 13 and the inner surface 38 the inner sleeve 34 is a third annular space extending in the axial direction 39 Shaped in one of the rotor 3 shaped first recess 40 empties.

The (outer) diameter of the outer sleeve 33 corresponds to the diameter of the second step room 30 , leaving an outer surface 41 the outer sleeve 33 at its two end portions of an inner peripheral surface 42 of the second step room 30 is applied. In its axial dimension is the outer sleeve 33 with respect to the axial distance of the two second ring stages 22 . 27 shortened so that between the inner peripheral surface 42 of the second step room 30 and the outer surface 36 the inner sleeve 34 a second annulus 43 shaped in fluid communication with the formed between inner and outer sleeve gap 44 stands.

The outer surface 41 the outer sleeve 33 forms together with an inner peripheral surface 45 of the first step room 29 a first annular space extending in the axial direction 46 ,

In the axial space between the third step room 31 and the fourth ring step 24 forms the first stepped bore 20 the camshaft 14 a first recess 50 at the fourth ring step 24 into the threaded hole 18 passes. The first recess 50 is in fluid communication with the third annulus 39 ,

The camshaft 14 is still with three axially offset radial bores 47 - 49 provided, wherein a first radial bore 47 in the first annulus 46 , a second radial bore in the second annulus 43 and a third radial bore in the second recess 50 empties.

In order to avoid that with an insufficient supply of pressure medium occurring during operation of the internal combustion engine at the camshaft alternating moments on the rotor 3 can be transferred, the rotor 3 by a locking device with the stator 2 locked in the middle position (base position) rotatably. The locking device comprises for this purpose an axial locking pin 51 in a shot 52 of the rotor 3 is included. The locking pin 51 is by a spring element 53 in one of the first side plate 9 shaped locking gate 54 urged, which the locking pin 51 for non-rotatable locking of stator 2 and rotor 3 surrounds positively.

The spring element 53 rests at one end on one of the second side plate 10 resting support part 55 from and engages with its other end in an unspecified recess of the locking pin 51 , To the locking pin 51 in his recording 52 push back, creating the positive connection between stator 2 and rotor 3 is canceled, the locking pin 51 be subjected to pressure medium on the front side. The locking pin 51 is provided for this purpose with a frontal recess.

In the Flügelzellenversteller 1 can the pressure chambers A, the pressure chambers B and the locking link 54 the locking device are fed independently with pressure medium, for which purpose three separate pressure medium paths are provided for supplying and discharging pressure medium.

For example, a first pressure medium path is set up for the pressure chambers A, which in the camshaft 14 shaped first radial bore 47 , the first annulus 46 and a fluidically connected to the pressure chambers A radial first fluid channel 56 includes, to which the first annulus 46 connected.

In a corresponding manner, a second pressure medium path, which is different from the first pressure medium path, is set up for the pressure chambers B, which second radial bore 48 , the second annulus 43 , the intermediate space formed between inner and outer sleeve 44 , As well as a fluidically connected to the pressure chambers B (not shown in the sections) comprises radial second pressure medium channel, to which the gap 44 connected.

For the supply of the locking link 54 one of the first and second pressure medium paths of different third pressure medium path is set, which is the third radial bore 49 , the second recess 50 , the third annulus 39 , the first recess 40 and a third pressure medium channel 57 which is the first recess 40 with the locking link 54 fluidically connects, includes.

The three radial bores 47 - 49 can each be connected to a pressure medium pump or a pressure medium tank to pressure fluid to the pressure chambers A, B and the locking link 54 to be supplied or deduced therefrom.

In the basis of the 1 to 7 illustrated vane cell adjuster 1 can through the control 32 in a simple manner an axial supply or discharge of pressure medium can be realized by means of three different pressure medium flows, thereby to supply the pressure chambers A, B and a locking device with separate pressure medium flows. In contrast to conventional camshaft adjusters can be advantageously dispensed with the production of axial pressure fluid channels in the camshaft, which can bring a high processing effort and can cause problems with residual dirt. In addition, the control allows 32 a particularly simple installation of the Flügelzellenverstellers 1 because the first to third annular spaces provide a simple flow connection between the camshaft 5 and rotor 3 allow.

The control 32 is preferably made of a plastic material, for example by injection molding, whereby manufacturing tolerances can be compensated in an advantageous manner.

The The embodiment shown in the figures can be simpler Be modified to more than three different pressure medium flows in the camshaft axially to the rotor. For example four different axial flows of pressure medium can be realized this is just a triple-sleeve of three concentric Provide single sleeves. Generally, that by a n-sleeve control (n is a natural number greater than 1) n + 1 different pressure medium flows in axial direction can be passed to the rotor.

1

Vane phasers

2

stator

3

rotor

4

peripheral surface

5

recess

6

wing

7

pressure chamber A

8th

pressure chamber B

9

first side plate

10

second side plate

11

cup-shaped housing section

12

fixing screw

13

central screw

14

camshaft

15

hub portion

16

screw shaft

17

threaded portion

18

threaded hole

19

screw head

20

first stepped bore

21

first Ring step (first stepped bore)

22

second Ring step (first stepped bore)

23

third Ring step (first stepped bore)

24

fourth Ring step (first stepped bore)

25

second stepped bore

26

first Ring step (second stepped bore)

27

second Ring step (second stepped bore)

28

third Ring step (second stepped bore)

29

first stepped space

30

second stepped space

31

third stepped space

32

control

33

outer sleeve

34

inner sleeve

35

support strut

36

outer surface (Inner sleeve)

37

inner Peripheral surface (third step room)

38

palm (Inner sleeve)

39

third annulus

40

first recess

41

outer surface (Outer sleeve)

42

inner Peripheral surface (second step space)

43

second annulus

44

gap

45

inner Peripheral surface (first step room)

46

first annulus

47

first radial bore

48

second radial bore

49

third radial bore

50

second recess

51

locking pin

52

admission

53

spring element

54

locking link

55

supporting part

56

first Pressure fluid channel

57

third Pressure fluid channel

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 202005008264 U1 [0010]
• - EP 1596040 A2 [0010]
• DE 102005013141 A1 [0010]
• - DE 19908934 A1 [0010]
• - DE 10135146 A1 [0016]

Claims (11)

Camshaft adjuster ( 1 ) for an internal combustion engine, comprising: - a driving part which is in driving connection with a crankshaft ( 2 ), - one with a camshaft ( 14 ) at its end side rotatably connected output member ( 3 ), the rotationally adjustable to the drive part ( 2 ) is mounted and its relative rotational position to the drive part by means of at least one oppositely acting pressure chamber pair ( 7 . 8th ) comprehensive hydraulic actuator is adjustable, - at least one axial sleeve comprehensive control ( 32 ), which in an at least partially formed by the camshaft cavity ( 20 . 25 ) is received so that a plurality of separate axial pressure medium lines are formed, which with pressure medium lines ( 56 . 57 ) in the stripping section ( 3 ) are fluidically connected, characterized in that the control ( 32 ) at least two sleeves (at least partially concentrically surrounding each other) ( 33 . 34 ), which are arranged so that at least three separate axial pressure medium lines ( 39 . 43 . 46 ) are formed. Camshaft adjuster according to claim 1, characterized in that adjacent sleeves ( 33 . 34 ) are formed so that the radially outwardly located sleeve ( 33 ) has a shorter axial dimension than the radially inner sleeve ( 34 ) Has. Camshaft adjuster according to claim 2, characterized in that the control element ( 32 ) is received in an axially stepped cavity. Camshaft adjuster according to one of claims 1 to 3, characterized in that the sleeves ( 33 . 34 ) by between the sleeves arranged support elements ( 35 ) are supported against each other. Camshaft adjuster according to one of claims 1 to 4, characterized in that the control element ( 32 ) in the form of a double sleeve with an inner sleeve ( 34 ) surrounding outer sleeve ( 33 ) is trained. Camshaft adjuster according to claim 5, characterized in that the inner sleeve ( 34 ) at its two end portions not from the outer sleeve ( 33 ) is surrounded. Camshaft adjuster according to claim 6, characterized in that the control element ( 32 ) in a stepped cavity ( 20 . 25 ), that a first axial pressure medium line ( 46 ) between the outer sleeve ( 33 ) and a peripheral surface ( 45 ) of the cavity, a second axial pressure medium line ( 44 ) between inner sleeve ( 34 ) and outer sleeve ( 34 ) and a third axial pressure medium line ( 39 ) are formed within the inner sleeve. Camshaft adjuster according to one of claims 5 to 7, characterized in that the control element ( 32 ) by an output part ( 3 ) with the camshaft ( 14 ) rotatably connecting central screw ( 13 ) in the stepped cavity ( 20 . 25 ) is fixed. Camshaft adjuster according to one of claims 1 to 8, characterized in that the camshaft ( 14 ) with at least three radial pressure medium lines ( 47 . 48 . 49 ), which with the at least three separate axial pressure medium lines ( 39 . 43 . 46 ) are fluidically connected. Camshaft adjuster according to one of claims 1 to 9, characterized in that the control element ( 32 ) is made of a plastic, for example by injection molding. Internal combustion engine with a camshaft adjuster according to one of claims 1 to 10.