DE102006027349A1 - Camshaft adjuster with an electromagnetic actuator - Google Patents

Abstract

The invention relates to an electromagnetic actuator for the actuation of a hydraulic control valve for a camshaft adjuster. For known from the prior art embodiments passes through a plunger (6) on both sides of an anchor (23). On both sides of the armature, the plunger is mounted via bearings in the electromagnetic actuator (2). According to the invention, a pin (31) extends from a yoke part (15) of the electromagnetic actuator (2) into a longitudinal bore (30) of the armature (23). Between journal (31) and armature (23) has a plain bearing bushing (34) is interposed. The inventive design results in a particularly compact design of the electromagnetic actuator (2), in particular with low axial extent and / or radial extent.

Description

Description Field of the invention

The The invention relates to a camshaft adjuster with a hydraulic Control valve, which over a pestle through an electromagnetic actuator can be acted upon, in particular according to the preamble of claim 1.

Background of the invention

Phaser serve to influence the relative angular position of a camshaft across from a crankshaft of an internal combustion engine, reducing timing the internal combustion engine can be influenced. This is special advantageous in terms of power delivery, the torque characteristic over the Speed, emissions, consumption and noise the internal combustion engine. For camshaft adjusters with a hydraulic Actuator is an adjustment via a change the hydraulic conditions over a hydraulic control valve. Such a control valve can via an electromagnetic Actuator, for example, by a motor control, driven or be regulated, over a plunger forces on that Control valve exercises and different control states of the control valve causes. Such a hydraulic control valve is in particular as a proportional valve educated. In an electromagnetic actuator can in the magnetic field a coil may be arranged an armature which is coupled to the plunger is and displaceable in the direction of adjustment in bearings in a direction of adjustment guided is.

DE 199 08 146 A1 discloses a guide of the anchor by means of a central longitudinal bore of the armature passing through the plunger. The plunger is guided on both sides of the armature in axial ball bearings transversely to the direction of adjustment. Two yoke parts of the actuator form an aligned longitudinal bore in which the armature is displaceable to form a radial clearance and radially outboard the axial ball bearing is supported.

Out DE 198 09 175 A1 and DE 198 18 126 A1 It is known to store the armature directly in the region of its outer circumferential surface relative to a yoke member or a bobbin in the form of a sliding bearing displaceable.

Object of the invention

Of the Invention is based on the object in a camshaft adjuster an improved storage of an armature of an electromagnetic Propose actuator.

Summary of the invention

According to the invention Problem solved by the features of independent claim 1. Further Embodiments of the invention will become apparent according to the dependent claims 2-11.

• a) Die "Verlängerung" des Ankers durch einen den Anker durchsetzenden Stößel mit einem auf der gegenüberliegenden Seite des Steuerventils angeordneten Axialkugellager bedeutet, dass die axiale Baulänge des Aktuators um die Breite des Axialkugellagers vergrößert ist ( DE 199 08 146 A1 ).
• b) Die Lagerung des Ankers im Bereich seiner außenliegenden Mantelfläche gemäß DE 198 18 126 A1 bedeutet, dass die radialen Abmessungen des Aktuators durch im Bereich der Mantelfläche wirkende Gleitlagerbuchsen vergrößert sind. Weiterhin ist die Mantelfläche des Aktuators an die Lagerbedingungen anzupassen, was erhöhte Fertigungsanforderungen für diese Mantelfläche bedeutet. Weiterhin scheiden weitere Funktionen im Bereich der Mantelfläche durch die Nutzung der Mantelfläche als Lagerfläche aus.

Basically, the invention is based on the consideration that a bearing of the armature as "cantilevered storage" in which two bearings are arranged on one side of the armature, due to the forces and moments and the installation conditions is not advantageous. Rather, the storage requires support by bearings on both sides of the anchor. Particular attention is directed to the invention in this case on the side facing away from the tappet side of the armature bearing. The invention furthermore makes use of the knowledge that the bearing arrangements known from the prior art are disadvantageous with regard to the installation space conditions:

• a) The "extension" of the armature by an armature passing ram with an arranged on the opposite side of the control valve thrust ball bearing means that the axial length of the actuator is increased by the width of the thrust ball bearing ( DE 199 08 146 A1 ).
• b) The bearing of the armature in the region of its outer circumferential surface according to DE 198 18 126 A1 means that the radial dimensions of the actuator are increased by acting in the region of the lateral surface plain bearing bushes. Furthermore, the lateral surface of the actuator to adapt to the storage conditions, which means increased manufacturing requirements for this lateral surface. Furthermore, other functions in the area of the lateral surface are eliminated by the use of the lateral surface as the bearing surface.

Furthermore is for to take into account both the above-mentioned bearing arrangements that the magnetic Flow between a coil, yoke parts and the armature through the bearing elements not disturbed may be. This means, for example, that arranged in the region of the lateral surface Slide bearing elements with a suitable material for building a Magnetic field must be formed.

The knowledge explained above, the invention takes account of the fact that the bearing, which is arranged on the opposite side of the plunger of the armature, having a pin. The pin can in this case be arranged fixed to the housing. At such a pin, the armature is supported in the region of a central longitudinal bore transversely to the direction of adjustment. This means that not an anchor-proof "extension" in the form of a cantilevered ram for storage (as under a)) or a lateral surface of the anchor (so under b)), but much more an inner surface of the armature is used, which is provided by the longitudinal bore. Hereby, a trained according to the prior art without special function area of the armature can be used for the training of the camp without the storage requires special measures in the area of the lateral surface and the end faces of the armature. In particular, a production of the lateral surface with a diameter enabling storage, tolerances and surfaces is not required. A production of a longitudinal bore and a pin is also particularly easy. Also has an embodiment of the bearing with respect to a pin guided longitudinal bore as u. U. proven advantageous in terms of the magnetic flux in the actuator.

While in the Frame of the invention quite an immediate leadership of Anchor on the pin or an intermediate circuit of a rolling bearing, such as an axial ball bearing, between pins and longitudinal bore possible is one hits Another embodiment of the invention that between pin and one the longitudinal bore limiting inner lateral surface of the anchor is a plain bearing bushing interposed. About the plain bearing bush can on simple and inexpensive Make the tribological conditions between pin and lateral surface be given constructive. As an example of such a plain bearing bush A brass bush or bronze bushing can be used. Also possible is a use of a PTFE coating in the region of the sliding surfaces, in particular the lateral surface of the pin, a lateral surface a plain bearing bush and / or the inner circumferential surface of Longitudinal bore.

The Plain bearing bush can without degree of freedom in the direction of adjustment with the Pin or be connected to the inner circumferential surface of the longitudinal bore, being for securing in the longitudinal direction a positive connection, for example by means of a locking ring, or can use a latching connection. For a special design the invention, the plain bearing bush is pressed into the longitudinal bore, which a particularly simple and inexpensive, but equally reliable connection option represents.

By Use of a plain bearing bush can continue the manufacturing requirements for a plain bearing bushing supporting lateral surface and / or a relatively moving lateral surface can be reduced.

Basically it is sufficient if the pin is fixed to the housing. A particularly compact embodiment of the camshaft adjuster according to the invention may arise when the pin (immediately) opposite a Supported yoke part of the actuator is.

U. U. only be made possible according to the invention can the design of the anchor as a sintered part, creating a special simple production and cost-effective production is possible. Because the lateral surface If the anchor does not have to fulfill any bearing tasks, this can be a special one Design "sinterrohroh" remain, so immediately as the starting product of the sintering process without further post-processing getting produced.

Furthermore is possible according to the invention that for a further embodiment of the camshaft adjuster of the anchor Equalizing grooves owns. Possible is that end faces of the armature bound on both sides of the armature chambers, in which a hydraulic medium is arranged. With a shift the anchor for an adjusting movement changes the volume of such a chamber, with an exchange of Hydraulic medium between the two chambers via the Ausgleichsnuten. The compensation grooves can arbitrary cross-sections and longitudinal extensions have and are formed in particular as grooves of the lateral surface, which are oriented in the direction of adjustment.

For another Embodiment of the camshaft adjuster according to the invention serves the longitudinal bore not just the recording of the pin. Rather, in the longitudinal bore also the ram pressed. Here, the longitudinal bore be designed as a through hole, which then, for example on the one hand forms a press fit with the plunger and on the other a shifting leadership of the pin guaranteed. Also possible is the stepped training of the longitudinal bore with different Diameters on the one hand for the pestle and on the other hand for the pin.

A Another embodiment relates to another, second camp, with the plunger in the radial direction supported is. Such a second bearing can with a plain bearing bush be formed, which has a radially inner circumferential surface, at the ram radial supported is. Such a plain bearing bush provides a simple, inexpensive, but still efficient design for a second camp, where with the first bearing and the second bearing the reliable support with Anchor and pestle formed Unit possible is.

In particular, the plain bearing bush of the further bearing is designed as a forming part. In a particular embodiment of the invention, this formed as a formed part plain bearing bush in half longitudinal section in a first approximation to be called U-shaped. The U-shaped half longitudinal section has two side legs oriented parallel to one another and to a direction of adjustment, as well as a base leg oriented transversely to the direction of adjustment. The inside lying side legs forms a lateral surface on which the plunger rests either solid or to form a sliding connection. The other side leg is supported on a bore of an adjacent housing-fixed component, in particular fastened, or forms with this a sliding connection. By means of the transverse to the direction of adjustment of the base leg of the U, a radial distance between the plunger and a bore of the adjacent component can be bridged, so that it is possible that a diameter of this bore to other requirements, such as a mounting option of the armature can be adjusted.

For a special compact design of a camshaft adjuster according to the invention is the other component is a yoke part of the actuator. Advantageous developments The invention will become apparent from the claims, the description and the drawings. The advantages mentioned in the introduction of features and combinations of several features are merely by way of example, without these necessarily being embodiments of the invention must be achieved. Other features are the drawings - in particular the illustrated Geometries and the relative dimensions of several components to each other as well as their relative arrangement and operative connection - can be seen. The combination of features of different embodiments the invention or features of different claims also different from the selected ones The antecedents of the claims possible and is hereby stimulated. This also applies to such features are shown in separate drawings or in their description to be named. These features can be combined with features of different claims. As well can in the claims listed Features for further embodiments the invention omitted.

Brief description of the drawings

Further Features of the invention will become apparent from the following description and its associated Drawings in which embodiments of the invention are shown schematically. Show it:

1 a schematic representation of an interaction of an electromagnetic actuator, a hydraulic control valve and a hydraulic actuator in a camshaft adjuster and

2 an exemplary embodiment of an electromagnetic actuator for use in a cam shaft adjuster according to the invention.

Detailed description of the invention

1 schematically shows a phaser 1 , which is an electromagnetic actuator 2 , a hydraulic control valve 3 and a hydraulic actuator 4 having. The actuator 2 , the control valve 3 and the actuator 4 are, unless otherwise described here, formed substantially according to the above-mentioned prior art occur as known from the prior art in operative connection with each other and are as known from the prior art into each other and integrated into the environment of the internal combustion engine. The hydraulic control valve 3 is designed in particular as a proportional valve.

At the actuator 4 For example, it is a vane-cell unit in which chambers are separated by a vane, depending on the pressurization of the chambers an adjusting movement between a rotor and a stator can be brought, which are coupled on the one hand with a drive means driven by a traction drive and on the other hand with a camshaft. The hydraulic loading of the chambers is determined by one of the position of the actuator 2 dependent operating position of the hydraulic control valve 3 given or influenced.

The electromagnetic actuator 2 is via electrical signals 5 controlled or regulated, with exemplary embodiments for a control or regulating method and for suitable electrical signals 5 for example DE 198 18 126 A1 can be seen. According to the electrical signals 5 generates the actuator 2 a force and / or a movement for a plunger 6 over which the control valve 3 can be acted upon or the operating position of the control valve 3 can be influenced. The hydraulic control valve 3 communicates with a hydraulic environment 7 in which it can handle an increased pressure level, for example, provided by a pump or a pressure reservoir o. Ä., And a pressure sink, such as a non-pressurized container han30 can. About the control valve 3 becomes the hydraulic environment 7 different in different operating positions via pressure medium connections 8th with the actuator 4 , in particular the hydraulic chambers of the actuator 4 , connected.

2 shows an exemplary embodiment of an electromagnetic actuator 2 , The electrical signals 5 become a coil 9 of the actuator 2 over a plug 10 fed. The plug 10 is in the region of the radially outer circumferential surface on a housing 11 of the actuator 2 attached and provides the possibility of a quick connection with egg a suitable mating connector ready with a supply of electrical signals 5 to the coil 9 ,

The sink 9 is coaxial with a longitudinal axis or direction of adjustment 12 - 12 educated. Guide the electrical signals 5 to a current in the coil 9 , thus inducing a magnetic field. The sink 9 , optionally with a magnetizable coil material, radially inwardly forms a recess 13 with cylindrical lateral surface 14 out. On the control valve 3 opposite side is in the recess 13 exactly fitting a yoke part 15 used. For the in 2 illustrated embodiment is the yoke part 15 rotationally symmetrical formed with a U-shaped longitudinal section, the two side legs 16 . 17 parallel to the direction of adjustment 12 - 12 are oriented, as well as a base leg 18 , which is transverse to the direction of adjustment 12 - 12 is oriented. The side legs 16 . 17 form a cylindrical surface 19 , the exact fit in the lateral surface 14 is used and attached to this. The circumferential side legs 16 . 17 form an inner hollow cylindrical surface 20 that a minor game 21 opposite a substantially cylindrical lateral surface 22 an anchor 23 formed.

Next to the yoke part 15 is located in the magnetic flux on the yoke part 15 opposite side a yoke part 24 , which with a circular disk 25 , the part of the case 11 is, as well as a Polkern 26 is formed. The Polkern 26 is coaxial with the direction of adjustment 12 - 12 arranged and formed approximately socket-shaped. The Polkern 26 is stuck in a hole 42 the circular disk 25 added. The Polkern 26 is in the half-longitudinal section as sketched with an acute angle of about 5 ° to 10 ° and protrudes into the interior of the housing 11 into it. The boundary surfaces 27 . 28 of the pole core 26 are opposite the direction of adjustment 12 slightly inclined and part cone shaped. The inclination of the inner boundary surface 28 corresponds to the inclination of the lateral surface 22 of the anchor 23 in the pole core 26 facing end region. In the outlined position according to 2 forms between polkernels 26 and anchor 23 A gap 29 out. A soft iron circle for that by means of the coil 9 induced magnetic field passes over the yoke part 15 , the case 11 , Circular disk 25 and polkernels 26 and becomes both between yoke part 15 as well as between yoke part 24 , in particular in the area of the pole core 26 , and the movably mounted anchor 23 transfer. The magnetic field exerts over the gap 29 a magnetic force on the anchor 23 in direction of adjustment 12 - 12 out. The anchor 23 is stuck with the pestle 6 coupled in the in 2 sketched position approximately flush with the housing 11 ends and in a different operating position from the housing 11 protrudes. The pestle 6 is fitting in a longitudinal bore 30 of the anchor 23 taken up and opposite the anchor 23 attached.

For storage, the yoke has part 15 a coaxial with the direction of adjustment 12 - 12 and longitudinal axis oriented pin 31 , For the in 2 illustrated embodiment is the pin 31 via a press fit in a centric bore 32 of the yoke part 15 added. The pin 31 extends to form a radial clearance in the longitudinal bore 30 of the anchor 23 , The longitudinal bore 30 owns in the yoke part 15 facing end region a cross-sectional widening 33 into which a plain bearing bush 34 is used. The plain bearing bush has a hollow cylindrical portion with an outer circumferential surface, which at the anchor 23 is applied, and an inner circumferential surface, which on the pin 31 is applied. Furthermore, the plain bearing bush has 34 via a radially outwardly oriented collar, which between an end face of the armature 23 and the base leg 18 of the yoke part 15 is arranged. The sliding contact of the sliding bush 34 can between the outer circumferential surface of the plain bearing bush 34 and the anchor 23 and / or between the inner circumferential surface of the plain bearing bush 34 and the pin 31 be educated. spigot 31 , Plain bearing bush 34 and the cross-sectional extension 33 of the anchor 23 form a first camp 35 ,

A second camp 36 is on the yoke part 15 opposite side of the anchor 23 arranged. For this purpose finds a plain bearing bush 37 Insert, by means of which the plunger 6 allowing movement in the direction of adjustment 12 - 12 radially to the direction of adjustment 12 - 12 opposite the pole core 26 is supported. For the in 2 illustrated embodiment is the plain bearing bush 37 formed with a U-shaped semi-longitudinal section. The U-shaped half-length cut is with side legs 38 . 39 parallel to each other and parallel to the direction of adjustment 12 - 12 are oriented, as well as an outboard, approximately in alignment with the outside of the circular disk 25 arranged base legs 40 , which is transverse to the direction of adjustment 12 - 12 oriented, educated. With the radially inner circumferential side legs 39 an inner cylindrical surface is formed, which makes a sliding contact with the plunger 6 forms, while the outer lateral surface, with the side legs 38 is formed, fitting inside on the pole core 26 is present or attached opposite this. For the in 2 illustrated embodiment has the side legs 38 a radially outwardly oriented collar located on a corresponding shoulder of the pole core 26 is applied.

At the plain bearing bush 37 it is in particular a forming part. The anchor 23 can be designed as a sintered part. Here, the lateral surface 22 of the anchor 23 "Sunstroh" stay, because the It does not have to fulfill any tasks during storage. In the anchor 23 can, in particular when trained as a sintered part, parallel to the direction of adjustment 12 - 12 oriented compensation grooves 41 in the lateral surface 22 be provided, which are evenly or irregularly distributed over the circumference and, for example, over the lateral surface 22 in 12 - 12 or extend spirally.

1

Phaser

2

electromagnetic actuator

3

hydraulic control valve

4

actuator

5

electrical signal

6

tappet

7

hydraulic Surroundings

8th

Pressure fluid connection

9

Kitchen sink

10

plug

11

casing

12

setting direction

13

recess

14

lateral surface

15

yoke

16

side leg

17

side leg

18

base leg

19

lateral surface

20

lateral surface

21

game

22

lateral surface

23

anchor

24

yoke

25

Annular disk

26

pole core

27

boundary surface

28

boundary surface

29

gap

30

longitudinal bore

31

spigot

32

drilling

33

Cross-sectional widening

34

plain bearing bush

35

first camp

36

second camp

37

plain bearing bush

38

side leg

39

side leg

40

base leg

41

equalizing groove

42

drilling

Claims (11)

Camshaft adjuster with a hydraulic control valve ( 3 ), which via a plunger ( 6 ) by an electromagnetic actuator ( 2 ) is acted upon, wherein in the actuator ( 2 ) one with the pestle ( 6 ) coupled anchor ( 23 ) in warehouses ( 35 . 36 ) in a direction of adjustment ( 12 - 12 ) is slidably guided, characterized in that a bearing ( 35 ), which on the the ram ( 6 ) opposite side of the armature ( 23 ) is arranged, a pin ( 31 ), on which the armature ( 23 ) in the region of a central longitudinal bore ( 30 ) transverse to the direction of adjustment ( 12 - 12 ) supported by allowing a relative displacement between pins ( 31 ) and anchors ( 23 ) in the direction of adjustment ( 12 - 12 ). Camshaft adjuster according to claim 1, characterized in that between pins ( 31 ) and one the longitudinal bore ( 30 ) limiting inner lateral surface of the armature ( 23 ) a plain bearing bush ( 34 ) is interposed. Camshaft adjuster according to claim 2, characterized in that the plain bearing bush ( 34 ) in the longitudinal bore ( 30 ) is pressed. Camshaft adjuster according to one of claims 1 to 3, characterized in that the pin ( 31 ) opposite a yoke part ( 15 ) of the actuator ( 2 ) is supported. Camshaft adjuster according to one of the preceding claims, characterized in that the armature ( 23 ) is a sintered part. Camshaft adjuster according to one of the preceding claims, characterized in that the armature ( 23 ) Compensation grooves ( 41 ) owns. Camshaft adjuster according to one of the preceding claims, characterized in that the plunger ( 6 ) in the longitudinal bore ( 30 ) is pressed. Camshaft adjuster according to one of the preceding claims, characterized in that a further bearing ( 35 ), with which the plunger ( 6 ) is supported in the radial direction, with a plain bearing bush ( 37 ) is formed, which has a radially inner circumferential surface, on which the plunger ( 6 ) is radially supported. Camshaft adjuster according to claim 8, characterized in that the plain bearing bush ( 37 ) of the further camp ( 35 ) is formed as a formed part. Camshaft adjuster according to claim 9, characterized in that the plain bearing bush ( 37 ) of the further camp ( 35 ) in a semi-longitudinal section in a first approximation U-shaped with two parallel to the direction of adjustment ( 12 - 12 ) oriented side legs ( 38 . 39 ) of the U and a transverse to the direction of adjustment ( 12 - 12 ) oriented legs ( 40 ) of the U, wherein the inner side leg ( 39 ) the Mantelflä surface at which the ram ( 6 ), while the outer side legs ( 38 ) in a bore ( 42 ) is supported by an adjacent housing-fixed component. Camshaft adjuster according to claim 10, characterized in that the adjacent component is a yoke part ( 24 ), in particular a pole core ( 26 ) is.