DE102011085572A1 - Hydraulic camshaft adjusting device i.e. vane-type adjuster, for use in combustion engine, has locking mechanism comprising openings, where one of openings of channels is arranged between other openings of channels of work chambers - Google Patents

Abstract

The device (1) has a locking mechanism for blocking and/or unblocking a relative twist between a focal distance (2) and an output element (3). The output element includes a central opening (6), and hydraulic unit channels (x, y, z) comprise a hydraulic unit for conducting hydraulic fluid to the locking mechanisms and work chambers. The channels comprise openings (a, b, c) that are spaced from a rotational axis (8) in an axial direction. One of the openings of the channels of the locking mechanism is arranged between other openings of the channels of the work chambers.

Description

Field of the invention

The invention relates to a camshaft adjuster.

Background of the invention

Camshaft adjusters are used in internal combustion engines for varying the timing of the combustion chamber valves in order to make the phase relation between crankshaft and camshaft in a defined angular range, between a maximum early and a maximum late position, variable. Adjusting the timing to the current load and speed reduces fuel consumption and emissions. For this purpose, camshaft adjuster are integrated into a drive train, via which a torque is transmitted from the crankshaft to the camshaft. This drive train may be formed for example as a belt, chain or gear drive.

In a hydraulic camshaft adjuster, the output element and the drive element form one or more pairs of mutually acting pressure chambers, which can be acted upon by hydraulic fluid. The drive element and the output element are arranged coaxially. By filling and emptying individual pressure chambers, a relative movement between the drive element and the output element is generated. The rotationally acting on between the drive element and the output element spring urges the drive element relative to the output element in an advantageous direction. This advantage direction can be the same or opposite to the direction of rotation.

One type of hydraulic phaser is the vane phaser. The vane cell adjuster comprises a stator, a rotor and a drive wheel with an external toothing. The rotor is designed as a driven element usually rotatably connected to the camshaft. The drive element includes the stator and the drive wheel. The stator and the drive wheel are rotatably connected to each other or alternatively formed integrally with each other. The rotor is coaxial with the stator and located inside the stator. The rotor and the stator are characterized by their, radially extending wings, oppositely acting oil chambers, which are acted upon by oil pressure and allow relative rotation between the stator and the rotor. The wings are either formed integrally with the rotor or the stator or arranged as "inserted wings" in designated grooves of the rotor or the stator. Furthermore, the vane cell adjusters have various sealing lids. The stator and the sealing lids are secured together via several screw connections.

Another type of hydraulic phaser is the axial piston phaser. In this case, a displacement element is axially displaced via oil pressure, which generates a helical gear teeth relative rotation between a drive element and an output element.

Another design of a camshaft adjuster is the electromechanical camshaft adjuster having a three-shaft gear (for example, a planetary gear). One of the shafts forms the drive element and a second shaft forms the output element. About the third wave, the system by means of an adjusting device, such as an electric motor or a brake, rotational energy supplied or removed from the system. A spring may additionally be arranged, which supports or returns the relative rotation between the drive element and output element.

The US 2004/0139937 A1 shows a camshaft adjuster with an assembly of an output element 9 , The working chambers by two juxtaposed hydraulic fluid channels 20 be supplied with hydraulic fluid. An adjoining in the axial direction of the working chambers locking mechanism 33 respectively. 47 couples the output element 9 with the drive element 3 ,

Summary of the invention

The object of the invention is to provide a camshaft adjuster which is particularly compact in the axial direction.

According to the invention, this object is solved by the features of claim 1.

In particular, in hydraulic camshaft adjusters, which have a drive element and an output member, each forming a plurality of wings, the wings divide oppositely acting working chamber and the working chambers are pressurized with hydraulic fluid to a relative rotation about the axis of rotation of the camshaft adjuster between the drive element and the output member reach, the arrangement of the hydraulic fluid channels is advantageous to form a weight-reduced camshaft adjuster, which also requires little space in the axial direction.

According to the invention it is achieved that a disposed within the driven element Locking mechanism can be controlled by its own hydraulic fluid channel without additional axial space. Preferably, the use of a central valve, which is received by a central opening of the camshaft at the camshaft adjuster end of the camshaft, is suitable. Alternatively, instead of the central valve, a hydraulic fluid channel adapter or sleeve assembly may hold the hydraulic fluid channels within the camshaft separate from each other. Keep the hoses separated from each other inside the camshaft. The hydraulic fluid channels of the output element each have an orifice, which are arranged in a central opening of the hub of the output element.

According to the invention the mouth of the hydraulic fluid channel of the locking mechanism between the mouths of the hydraulic fluid channels of the working chambers is arranged. Particularly advantageous is the invention under realization of a lock in intermediate position. The intermediate position is the position between the input member and the output member where the displacement angle is greater than zero, i. the position can be found within the adjustment range. For example, in a hydraulic camshaft phaser with vane, there is a spacing of a vane of the output member to an associated vane of the driver, so that these two vanes do not contact each other.

In addition to the lock for the intermediate position, further interlocks can be used. Preferably, a further locking in base position is provided. The base position is the position between the input member and the output member where the displacement angle is zero or maximum, i. This position can be found in one of the extreme positions of the adjustment between the drive element and output element. For example, in a hydraulic camshaft phaser with vane spacing of a wing of the output member to an associated wing of the drive member is not provided, so that in this position of the drive element to the output member whose wings contact each other.

With the inventive arrangement of the hydraulic fluid channels in the camshaft adjuster, or their mouths to the camshaft, which leads to the individual consumers, such as working chambers and locking mechanism, an extremely compact and especially in the axial direction space-saving arrangement of the hydraulic fluid channels and the consumer itself is possible.

Next is a separate possibility of control, the lock for the base position and the lock for the intermediate position, is given according to the invention by the arrangement of the hydraulic fluid channels.

An orifice is defined as the inlet or outlet cross section of the respective hydraulic fluid channel of the output element. It can be designed as a plane or spatially curved cross-sectional area.

In one embodiment of the invention, an opening of a hydraulic fluid channel is formed partially encircling. Advantageously, thus an increased and thus expensive requirement for the angular positioning accuracy between the mouth and one of these opposing opening is reduced and additional angular positioning means can be dispensed with. In addition, the possibility is given to form the mouth in addition to training in the circumferential direction in the axial direction and to nest with an adjacent mouth to save further axial space.

Ideally, an opening of a hydraulic fluid channel is formed completely circumferentially. A requirement for an angular positioning, so that the mouth of the associated opening faces, can be completely eliminated.

In a particularly preferred embodiment, a hydraulic fluid channel has a crescent-shaped recess. The sickle-shaped recess is advantageous on the one hand to form a partially circumferential mouth of the hydraulic fluid channel. On the other hand, the crescent-shaped recess in the inventive arrangement of the hydraulic fluid channels is a simple and inexpensive, e.g. by a side milling cutter, geometry to be produced in order to connect in the further course of the hydraulic fluid channel further sections of the hydraulic fluid channel fluid-conducting. The further sections may be formed by bores or other types of material recesses.

In one embodiment of the invention, openings of a camshaft projecting into the central opening are opposite the openings of the output element. The camshaft has within the hub of the camshaft adjuster at least three axially spaced openings. The mouths of the output element are formed and arranged on the inner peripheral surface of the central opening. Ideally, these openings are each facing openings of the camshaft, which are formed by an outer peripheral surface of the camshaft. So a direct hydraulic fluid transfer is formed. The camshaft at least partially penetrates the central opening of the driven element.

Alternatively, instead of a camshaft, a hydraulic fluid adapter or a sleeve assembly may have these openings.

In a further embodiment of the invention, the drive element is received by the central opening of the output element in such a way that corresponding to some mouths of the output element corresponding openings of the drive element. The drive element may have a hub provided for this, which engages in the central opening of the output element. The openings of the drive element are provided for the supply of hydraulic fluid. Thus, mouths of the drive element are opposite the mouths of the output element, but in the inventive arrangement and sequence in the axial direction.

In a preferred embodiment, an intermediate position of the drive element is defined to the output element by the locking mechanism. The intermediate position is, according to the above definition, a position of the drive element to the output element within the adjustment range, ideally the center position, i. almost the middle of the adjustment range.

In a further embodiment of the invention, the hydraulic fluid channel of the locking mechanism leads in the further course of the locking mechanism out of the driven element out into a groove of a cover element.

The groove of the lid member is also formed as a locking link and in its course partially in the circumferential direction. The groove of the lid member faces a further mouth of the hydraulic fluid channel. The hydraulic fluid channel directs hydraulic fluid from the mouth to the central opening to the mouth to the groove of the lid member.

In an advantageous embodiment, the locking mechanism has a plurality of individual locks. The formation of multiple latches to secure a position, e.g. the base position, the intermediate position or the center position, advantageously increase the reliability because at least one locking piston with its associated locking link is engaged or engageable. The requirement for a reliable securing of the position is thereby increased, because it may have the one or more other locking piston a short-term malfunction, wherein at least one of the other locking piston is operated properly.

The output element has a spring space in which a restoring spring is arranged. The return spring has windings which are arranged successively in the axial or radial direction and define the winding body. The return spring generates a torque between the input member and the output member in a rotational direction to assist the relative rotation. Several return springs are alternatively conceivable to support both directions of rotation of the drive element and driven element respectively or to increase the torque in one direction by the use of multiple return springs.

In a particularly advantageous embodiment, a hydraulic fluid channel of a working chamber leads to a spring chamber. The spring chamber is preferably arranged in the radial direction between the working chambers and the hub of the output element with the central opening. The hydraulic fluid to the working chamber passes through the spring chamber, which advantageously acts as a hydraulic fluid reservoir and at the same time the turns of the return spring are lubricated.

In a particularly preferred embodiment of the invention, one of the locking mechanisms has a fluid-conducting connection to the spring chamber. The stored in the spring chamber volume of hydraulic fluid is passed on a short path to the locking mechanism and operated on the other hand by the fluid-conducting connection with the working chamber at the same time as the pressure of the working chamber. This reduces the response time and synchronizes the operation of the locking mechanism with the working chamber.

The inventive arrangement of the hydraulic fluid channels in the hub of the driven element a compact design in the axial direction is achieved, taking into account the separate control of locking mechanism and working chambers.

Brief description of the drawings

Embodiments of the invention are illustrated in the figures.

Show it:

1 a longitudinal section through a camshaft adjuster according to the invention along the section line II of 2 to 4 .

2 a first cross section of the camshaft adjuster after 1 along the section line II-II 1 .

3 a second cross section of the camshaft adjuster after 1 along the section line III-III 1 and

4 a third cross section of the camshaft adjuster after 1 along the section line VI-VI 1 ,

Detailed description of the drawings

1 shows a longitudinal section through a camshaft adjuster according to the invention 1 along the section line II of 2 to 4 ,

The camshaft adjuster 1 has a drive element 2 and an output element 3 on which coaxial with each other and the axis of rotation 8th of the camshaft adjuster 1 are arranged. The drive element 2 and the output element 3 each have several radially directed wings 4 , with which oppositely acting working chamber A, B are divided. The operation of such a Flügelzellenverstellers is known from the prior art.

The output element 3 has a central opening 6 which is from one end of a camshaft 6 is completely penetrated. The output element 3 is by means of a mother 19 against a stop surface of the camshaft 9 with the camshaft 9 Tense against rotation. The output element 3 and the drive element 2 be through a cover element 12 and a side cover 18 in the axial direction 7 limited. The drive element 2 has on an outer circumferential surface a toothing for a, known from the prior art operative connection with a traction mechanism. The cover element 12 and the side cover 18 be with the drive element 2 Tense against rotation.

Radial between the working chamber A, B and the central opening 6 is a spring room 11 from the output element 3 designed, which for a return spring 16 is provided. The operation of the return spring 16 is also known from the prior art.

The output element 3 has three orifices a, b, c, which according to the invention in the axial direction 7 are arranged consecutively. In this case, the mouth b, which is associated with the hydraulic fluid channel y, between those orifices a and c, which are assigned to the hydraulic fluid channels x and z, respectively. The hydraulic fluid passage y guides the hydraulic fluid to a locking mechanism 5 to and the hydraulic fluid channels x and z lead the hydraulic fluid to the working chamber A and B. The mouths a, b and c are formed completely circumferential. The orifices a, b, c are thus circumferential, curved surfaces through which hydraulic fluid flows. At the mouths a, b, c of the hydraulic fluid channels x, y and z each have a groove closes 15 at. The openings a, b and c are respectively openings x ', y' and z 'of the camshaft 9 opposite, whereby the hydraulic fluid through the camshaft 9 to the camshaft adjuster 1 can get. The openings x ', y' and z 'are as holes 17 educated. An orientation of the angular position between the output element 3 and the camshaft 9 is not necessary, because the mouths a, b and c are formed circumferentially, whereby the openings x ', y' and z 'are always in fluid communication therewith.

The cover element 12 has an at least partially circumferential groove 13 , which as part of the hydraulic fluid channel y for the locking mechanism 5 is trained. The groove 13 is formed by a recess formed predominantly in the axial direction 20 supplied with hydraulic fluid. The axial recess 20 is in turn cut by a crescent-shaped recess 10 , which in turn with the groove 15 communicated. The groove 13 the lid element 12 distributes the hydraulic fluid in the circumferential direction of two latches 5a and 5c the locking mechanism 5 , The locks 5a and 5c are for locking in intermediate position, with the remaining third lock 5b the locking mechanism 5 is intended for locking base position.

The camshaft 9 has a largely constant outer diameter, which is the constant inner diameter of the central opening 6 contacted. Stepped training of the camshaft 9 , which with stepped training of the central opening 6 correspond, are conceivable. The openings x ', y' and z 'are four times evenly distributed over the circumference. Alternatively to the formation as a bore, the openings x ', y' and z 'may be formed as slots or slots.

2 shows a first cross section of the camshaft adjuster 1 to 1 along the section line II-II 1 , The 2 shows in its sectional plane the course of the hydraulic fluid along the hydraulic fluid channel x for the working chamber A. The hydraulic fluid channel x is fed from the openings x 'of the camshaft 9 , These openings x 'open into the circumferential orifice a of the hydraulic fluid channel x. The circumferential mouth a is part of the groove 15 at this axial position, which is the camshaft bearing remote position.

The following course takes the hydraulic fluid to the working chamber A. Through the mouth a, the hydraulic fluid from the openings x 'of the camshaft 9 in the camshaft adjuster 1 and collects in the circumferential groove 15 , Starting from this groove 15 the hydraulic fluid channel x extend 3 Evenly distributed over the circumference and radially directed holes 16 of the output element 3 , These holes 16 be from the spring chamber 11 interrupted, whereby the hydraulic medium is also in the spring chamber 11 will collect. Starting from the spring chamber 11 continue in the course of drilling 16 the hydraulic fluid is supplied to the working chamber A. There are three working chambers A and three oppositely acting working chambers B available.

The lock 5b the locking mechanism 5 can over the spring chamber 11 be supplied and printed. This is done via not shown grooves in the cover element 12 wherein a groove of the lid member 12 as known from the prior art, as a locking link for the lock 5b is provided. By printing the hydraulic fluid channel x thus the lock 5b pressed and unlocked. Preferably, the lock is 5b assigned to the base item.

3 shows a second cross section of the camshaft adjuster after 1 along the section line III-III 1 , The 3 shows in its sectional plane the course of the hydraulic fluid along the hydraulic fluid channel y for the locking mechanism 5 , The hydraulic fluid channel y is fed from the openings y 'of the camshaft 9 , These openings y 'open into the circumferential mouth b of the hydraulic fluid channel y. The circumferential mouth b is part of the groove 15 at this axial position, the central position between the hydraulic fluid channels x and z.

Following course takes the hydraulic fluid to the locking mechanism 5 , About the mouth b, the hydraulic fluid from the openings y 'of the camshaft occurs 9 in the camshaft adjuster 1 and collects in the circumferential groove 15 , Starting from this groove 15 of the hydraulic fluid channel y close two, approximately diametrically opposed crescent-shaped recesses 10 at. The crescent-shaped recesses 10 can be easily introduced through a side milling cutter. The side milling cutter first finds its coaxial position with the axis of rotation 8th , is then delivered radially and forms the crescent-shaped pockets. The respective zenith of each crescent-shaped recess 10 in turn each intersects an axial recess 20 at. The axial recesses 20 transport the hydraulic fluid further in the axial direction 7 to the lid element 12 with his groove 13 which in fluid communication with these axial recesses 10 stands. The groove 13 is at the same time the locking link of the locks 5a and 5c the locking mechanism 5 , By printing the hydraulic fluid channel y, the locks 5a and 5c operated and unlocked. Preferably, the locks position 5a and 5c the output element 3 to the drive element 2 in an intermediate position.

4 a third cross section of the camshaft adjuster after 1 along the section line VI-VI 1 , The 4 shows in its sectional plane the course of the hydraulic fluid along the hydraulic fluid channel z for the working chamber B. The hydraulic fluid channel z is fed from the openings z 'of the camshaft 9 , These openings z 'open into the circumferential mouth c of the hydraulic fluid channel z. The circumferential orifice c is part of the groove 15 at this axial position, which is the camshaft bearing near position.

The following course takes the hydraulic fluid to the working chamber B. About the mouth c, the hydraulic fluid from the openings z 'of the camshaft 9 in the camshaft adjuster 1 and collects in the circumferential groove 15 , Starting from this groove 15 of the hydraulic fluid channel z extend 3 Evenly distributed over the circumference and radially directed holes 16 of the output element 3 , These three holes 16 each guide the hydraulic fluid into the respective working chamber B.

LIST OF REFERENCE NUMBERS

1

 Phaser

2

 driving element

3

 output element

4

 wing

5

 locking mechanism

5a

lock

5b

lock

5c

lock

6

 central opening

7

 axial direction

8th

 axis of rotation

9

 camshaft

10

crescent-shaped recess

11

spring chamber

12

cover element

13

Groove (cover element)

14

Return spring

15

 Groove (output element)

16

Bores (output element)

17

Bores (camshaft)

18

side cover

19

mother

20

axial recess

a

 muzzle

b

 muzzle

c

 muzzle

x

 Hydraulic fluid channel

y

 Hydraulic fluid channel

z

 Hydraulic fluid channel

x '

 opening

y '

 opening

z '

 opening

A

 working chamber

B

 working chamber

V

 fluid-conducting connection

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 2004/0139937 A1 [0007]

Claims (10)

Camshaft adjuster ( 1 ) with - a drive element ( 2 ) and an output element ( 3 ) and a plurality of working chambers (A, B), - wherein the working chambers (A, B) are pressurizable with hydraulic fluid to a relative rotation of the drive element ( 2 ) to the output element ( 3 ) about the axis of rotation ( 8th ) of the camshaft adjuster ( 1 ), - wherein a locking mechanism ( 5 ) are provided, the relative rotation between the drive element ( 2 ) and the output element ( 3 ) can lock or unlock, - wherein the output element ( 3 ) a central opening ( 6 ) and - a plurality of hydraulic fluid channels (x, y, z), the hydraulic means to the locking mechanism ( 5 ) and the working chambers (A, B), - wherein the hydraulic fluid channels (x, y, z) mouths (a, b, c) to the central opening ( 6 ), these openings (a, b, c) being in the axial direction ( 7 ) of the axis of rotation ( 8th ), characterized in that the mouth (b) of the hydraulic fluid channel (y) of the locking mechanism ( 5 ) between the mouths (a, c) of the hydraulic fluid channels (x, z) of the working chambers (A, B) is arranged. Camshaft adjuster according to claim 1, characterized in that an orifice (a, b, c) of a hydraulic fluid channel (x, y, z) is partially formed circumferentially. Camshaft adjuster according to claim 2, characterized in that a hydraulic fluid channel (x, y, z) is a crescent-shaped recess ( 10 ) having. Camshaft adjuster according to claim 1, characterized in that the orifices (a, b, c) corresponding openings (x ', y', z ') one in the central opening ( 6 ) projecting camshaft ( 9 ). Camshaft adjuster according to claim 1, characterized in that the drive element ( 2 ) from the central opening ( 6 ) is received such that some mouths (a, b, c) of the output element ( 3 ) corresponding openings of the drive element ( 2 ). Camshaft adjuster according to claim 1, characterized in that the locking mechanism ( 5 ) an intermediate position of the drive element ( 2 ) to the output element ( 3 ) Are defined. Camshaft adjuster according to claim 1, characterized in that the hydraulic fluid channel (y) of the locking mechanism ( 5 ) in the further course to the locking mechanism ( 5 ) from the output element ( 3 ) out into a groove ( 13 ) a cover element ( 12 ) leads. Camshaft adjuster according to claim 1, characterized in that the locking mechanism ( 5 ) of a plurality of individual locks ( 5a . 5b . 5c ) consists. Camshaft adjuster according to claim 1, characterized in that a hydraulic fluid channel (x, z) of a working chamber (A, B) to a spring chamber ( 11 ) a return spring ( 14 ), which torque between the drive element ( 2 ) and output element ( 3 ) generates leads. Camshaft adjuster according to claim 8 and 9, characterized in that the one of the locks ( 5a . 5b . 5c ) a fluid-conducting connection (V) to the spring chamber ( 11 ) Has.

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