DE102013217905A1 - Camshaft adjuster with movement decoupling component between pin and control piston - Google Patents

Abstract

The invention relates to a camshaft adjuster (1) with a central valve (2) having pressure fluid openings (3) in which a control piston (4) is longitudinally displaceable in the direction of an axis of rotation (5) of the camshaft adjuster (1) for opening or closing the pressure fluid openings (3) with an actuator having a pin longitudinally displaceable in the direction of rotation, wherein the pin and the control piston (4) are positioned relative to each other so that axial forces are transmitted between them depending on the case, wherein between the pin and the control piston (4) an axialkraftweiterendes intermediate component (6) is arranged, wherein the intermediate member (6) is arranged rotatably as Bewegungsentkopplungsbauteil (7) to the pin and the control piston (4).

Description

Field of the invention

The invention relates to a camshaft adjuster, comprising a central valve having one or more radial pressure fluid openings, in which a control piston is arranged longitudinally displaceable in the direction of an axis of rotation of the camshaft adjuster for opening or closing the pressure fluid openings, and with an actuator / actuator having a pin which can be displaced electromagnetically in the direction of rotation axis / Tappet, wherein the pin / plunger and the control piston are positioned to each other so that case-dependent axial forces are transmitted between them, wherein between the pin and the control piston a axialkraftweiterbendes intermediate member is arranged.

From the prior art, the use of camshaft adjusters is known, for example. From the DE 10 2006 031 517 A1 , There is disclosed a switching device for a pressure oil operated camshaft adjuster. This camshaft adjuster, which as such is connected to a camshaft drive train via a camshaft sprocket and permits a change in the cam position of a camshaft relative to that camshaft wheel during operation of a corresponding internal combustion engine, has specific features. It has a valve device which comprises a valve housing element and a valve slide element which is accommodated in the valve housing element. It also has an actuator for causing a displacement of the valve spool member in the valve housing member from a first position, which causes a first switching state, to a second position, which causes a second switching state. The actuator has a coil device, a plunger element and an armature, which is displaceable in accordance with a voltage applied to the coil device voltage of a first Aktuatorschaltstellung in a second Aktuatorschaltstellung. The armature is coupled via that plunger element with the displacement element. As a special feature, the DE 10 2006 031 517 A1 out that an adjustment structure is provided to vote the switching position correlation of the actuator with the valve device. For complete elimination of dead play between the plunger element and the support element, the armature is urged in the coil housing in its axial end position in the armature housing, and then pressed the plunger element through the armature until the head is seated on the support member and the valve slide element also its maximum disengaged Reached position.

Such camshaft adjusters with central valve pistons and magnetic pins make variable cam timing devices feasible. Unfortunately, the previous solutions in terms of wear are still optimized. Thus, the pin / actuating pin, which is translationally displaceable by a magnet, partly even in the de-energized state already permanent contact with the control piston, which can also be referred to as a slide and is part of the central valve. It is not known if he can rotate in this position. If the magnet is energized, the pin moves against the rotating slide and due to the magnetic forces, the pin can then no longer rotate. As a result, it acts in the manner of a drill with respect to a flat surface of the slide / control piston on which it meets when transmitting axial force. As a result, it generates wear on the flat surface / plane surface of the slide / control piston, whereby the tip of the pin itself wears.

It is the object of the present invention to eliminate or at least reduce the disadvantages of the prior art and to eliminate the previously systemic "Bohrverschleiß" to reduce and / or to distribute the wear depth or the wear volume such that the wear-induced stroke loss of Control piston is minimized. In addition, a cost reduction with simultaneous manufacturability of different variants should be achieved.

Disclosure of the invention

This object is achieved in a generic device according to the invention in that the intermediate component is arranged rotatably as Bewegungsentkopplungsbauteil to the pin and the control piston. The movement decoupling member is rotatably disposed to each of the two components mentioned.

It must then no longer be a flat surface / plane surface of the control piston held. Also, the control piston can be made of a tube and thus be made cheaper than forming part, as before. This also saves material.

Advantageous embodiments are claimed in the subclaims and are explained in more detail below.

Thus, it is advantageous if the movement decoupling component is rotatably mounted in a pin facing the end of the control piston or rotatably mounted on a control piston facing the end of the pins. On the one hand, the movement decoupling component, for example, formed as a ball or spherical disc, can then be inserted into the distal end of the control piston / slider, while on the other hand, on the pin / Plunger, on the distal end, which faces the control piston, a cup-like cover can be applied. Thus, although axial forces can be transmitted, the rotation of the control piston, which is ultimately drehunverschieblich stored in the central valve, which in turn drehunverschieblich coupled to the rotor, that is coupled to the camshaft, then has no wear on the force in the axial direction element or the axialkraftaufnehmende Element.

An advantageous embodiment is also characterized in that the Bewegungsentkopplungsbauteil is designed as a ball or cap-like shoe. The sliding shoe can then be formed like an elephant foot and can be put over the distal end of the pin. The assembly is facilitated.

It is also wear-reducing if there is a spherical contact between the movement decoupling component and the pin or the control piston. It is also expedient if the movement decoupling component has a convex surface facing the pin and / or the control piston.

It should also be noted that it is advantageous if the surface is formed like a spherical segment. Alternatively, the surface may also be ellipsoidal.

If the ball is retained axially by a retaining clip but is rotatably supported in all directions in a receiving opening in the pin-facing end face of the control piston, the ball can simply be set in motion, for instance by gravity and when the motor is running on the ball Centrifugal force, wherein within their play in the bracket and / or by rotation by the control piston and / or via corresponding contact and / or oil shear and / or rotation by the eccentric Ölumströmung a movement is initiated.

It is also advantageous if the retaining clip, the ball and the receiving opening are coordinated so that the ball of pressurized fluid, such as oil can be flowed around. The coupling of the individual components in the manner of a sliding bearing is then made possible.

It is also advantageous if on the side facing away from the pin of the ball is a fixing washer in contact with the ball / is befindlich, wherein the fixing plate preferably has an oil passage / oil passage opening and further preferably has a cross-shaped cross-section.

It is also advantageous if a gap that can be filled with lubricating grease is present between the sliding shoe and the pin.

An advantageous embodiment is also characterized in that the control piston is made of plastic or includes such plastic.

Likewise, it is advantageous if the movement decoupling component consists of a metal alloy or includes this metal alloy.

In other words, a ball with a simple metal clip is used instead of a conventional flat surface / flat surface in which the ball can move and supports friction, so that due to the ball rotation and movements of the otherwise occurring "Bohrverschleiß" is minimized and the wear volume the entire sphere surface and a larger area of the pin is distributed.

Instead of the plane surface, a ball with mounting stop tabs in the control piston is fixed in a friction-free and easily movable manner with a simple fixing disk, so that oil flows during operation produce an additional rotational force on the ball.

The dimensional chain with tolerances of the system is adjusted so that in the de-energized magnet a clearance between the pin and the control piston with and without ball is present.

On the non-magnetic pin, a wear-resistant sliding shoe with a large tap radius is attached in a variant. The result is a higher absorbable wear volume.

While so far the magnet has pressed the pin with its tip against a plane surface of the rotating control piston, this is now solved differently. When energized magnet now a game between the pin and the control piston is present.

The magnet pushes the pin with its flat face executed after overcoming the game against the ball, which is guided in the retaining clip and axially fixed in both directions. The retaining clip is supported on the magnet-side end face of the control piston and consists of three or more legs, so that the ball can be well flowed around by oil. The ball then experiences different driving forces, such as those that are due to gravity, which are caused by centrifugal force caused by running, caused by forced movements / rotation of the control piston at contact points of the ball with the control piston and by occurring oil shear and / or rotation caused by an eccentric Ölumströmung.

In one variant, the magnet pushes the pin with its plan executed end face after overcoming the game against the ball, which is held axially and radially in the control piston through the fixing disc with Öldurchströmkanälen and through the mounting stop with play. The fixing is accurately positioned and fixed with the Öldurchströmkanälen as a sheet metal cross with wedge shape in the control piston bore.

Alternatively, the magnet can push the pin with the sliding shoe against the plane of the rotating control piston. With de-energized magnets, there is a clearance between the pin and the control piston. The sliding shoe is held on the pin with lubricating grease and has a large radius, for example greater than or equal to 100 mm, from a contact surface to the plane surface of the piston.

The invention will be explained in more detail with the aid of a drawing, in which different embodiments are shown. Show it:

1 a longitudinal section of a first embodiment of a camshaft adjuster according to the invention,

2 a second embodiment in a for 1 comparable presentation,

3a a side view of a fixing disc, similar to one, which in the second embodiment according to 2 is in contact with a ball-like motion decoupling element within a control piston bore,

3b a plan view of the fixing from 3a , and

4 a third embodiment of a camshaft adjuster according to the invention, in which, unlike the first two embodiments instead of a ball, a sliding block is used and this is also different than in the first two embodiments attached to the pin and not on the control piston.

The figures are merely schematic in nature and are only for the understanding of the invention. The same elements are provided with the same reference numerals. Individual aspects of the embodiments can be interchanged. Features that are not shown as essential to the invention are purely optional.

In 1 is a section of a first camshaft adjuster according to the invention 1 shown. The camshaft adjuster 1 has a central valve 2 on, the Druckfluidleitöffnungen 3 has pointing radially outward. Through the Druckfluidleitöffnungen 3 Pressure fluid, such as hydraulic fluid, such as oil spent in vane between a rotor, not shown, and a stator, not shown.

The central valve 2 is inserted into the rotor and non-positively inserted into a camshaft, not shown, for example. Screwed.

Concentric within the central valve 2 is a control piston 4 used. The control piston 4 is inside the central valve 2 along a rotation axis 5 arranged longitudinally displaceable.

The longitudinal displacement is caused by the action of a pin / plunger. The pin itself is not shown. Its shape in the end is but out 4 deducible.

The pin is moved axially by a magnet, with appropriate energization, evoking an electromagnetic force, so that a tip of the pin on an intermediate component 6 meets. The intermediate component 6 is as a movement decoupling component 7 educated. The motion decoupling component 7 can, as in the embodiment of 1 and 2 represented as a sphere 8th be formed, or, as in the embodiment according to 4 shown as a sliding shoe 9 be educated. The sliding shoe 9 can also be called a cap.

Coming back to the embodiment according to 1 be explained that a retaining clip 10 on a magnet-side end face 11 supported. The retaining clip 10 consists of several thighs 12 , Between the retaining clip 10 and the ball 8th is a game 13 available.

A magnet pushes the pin, not shown, with its flat end face after overcoming the game 13 against the ball 8th in the retaining clip 10 guided and fixed axially in both directions.

Something different is the ball 8th in the control piston 4 according to the second embodiment, see 2 , held. There will be a fixing disc 14 used, which Öldurchströmkanäle 15 having. The fixing disc 14 can also have a polygonal, square or round outer edge and with a mounting stop 16 on the retaining clip 10 interact. The fixing disc 14 can be attached to the retaining clip 10 be firmly attached.

In the 3a and 3b are two views of the fixing disc 14 reproduced, wherein the fixing disc 14 basically a cross-shaped Cross section and the individual cross legs 17 all are the same length.

Waiving a ball 8th , which is additionally usable, can also, as in 4 represented, the sliding shoe 9 attached to a distal end of the pin, wherein the sliding shoe 9 a spherical surface 18 has, which is provided by a radius R, which is about 100 mm in size. The crowned surface 18 meets a flat face 19 of the control piston 4 , after overcoming a gap 20 ,

LIST OF REFERENCE NUMBERS

1

 Phaser

2

 central valve

3

 Druckfluidleitöffnung

4

 spool

5

 axis of rotation

6

 between component

7

 Movement decoupling component

8th

 Bullet

9

 shoe

10

 retaining clip

11

 face

12

 leg

13

 game

14

 affixation

15

 Öldurchströmkanal

16

 assembly stop

17

 cross leg

18

 spherical surface

19

 plane face

20

 distance

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102006031517 A1 [0002, 0002]

Claims (4)

Camshaft adjuster ( 1 ) with a pressure fluid openings ( 3 ) having central valve ( 2 ), in which for opening or closing the pressure fluid openings ( 3 ) a control piston ( 4 ) in the direction of a rotation axis ( 5 ) of the camshaft adjuster ( 1 ) is longitudinally displaceable, and with an actuator having a longitudinally displaceable pin in the rotational direction, wherein the pin and the control piston ( 4 ) are positioned relative to one another in such a way that axial forces are transmitted between them, whereby between the pin and the control piston ( 4 ) an axial force-yielding intermediate component ( 6 ), characterized in that the intermediate component ( 6 ) as a movement decoupling component ( 7 ) to the pin and the control piston ( 4 ) is rotatably arranged. Camshaft adjuster ( 1 ) according to claim 1, characterized in that the movement decoupling component ( 7 ) rotatably in a pin facing the end of the control piston ( 4 ) or rotatable on a control piston ( 4 ) facing the end of the pin is attached. Camshaft adjuster ( 1 ) according to one of claims 1 to 2, characterized in that the movement decoupling component ( 7 ) as a ball ( 8th ) or sliding shoe ( 9 ) is trained. Camshaft adjuster ( 1 ) according to one of claims 1 to 3, characterized in that between the movement decoupling component ( 7 ) and the pin or the control piston ( 4 ) there is a spherical contact.

Images