DE102017126169B4 - Hydraulic camshaft adjuster - Google Patents

Abstract

The invention relates to a hydraulic camshaft adjuster (1), comprising a stator (2) in which a rotor (3) is rotatably arranged, wherein the stator (2) has at least one wing (4), and a locking system (6, 7, 8, 9, 10), with which the rotor (3) relative to the stator (2) in a center position (M) can be locked. In order to easily approach the center position, the invention provides that the locking system (6, 7, 8, 9, 10) comprises a fluid line (8) which is incorporated in at least one of the wings (4), wherein the fluid line ( 8) has a first portion (8a) permitting a flow of hydraulic fluid from a first sub-chamber (A) into a second sub-chamber (B) and a second portion (8b) containing a flow of hydraulic fluid from the second sub-chamber (8). B) into the first sub-chamber (A), wherein in the first section (8a) of the fluid line (8) a first check valve (9) is arranged, the flow of hydraulic fluid from the first sub-chamber (A) into the second sub-chamber (B ) and prevented in the opposite direction, wherein in the second section (8b) of the fluid line (8) a second check valve (10) is arranged, which allows the flow of hydraulic fluid from the second sub-chamber (B) in the first sub-chamber (A) and in the opposite direction g prevents, wherein the first control element (6) in a position of the rotor (3), in which the first control element (6) is not in a link (11), the flow of hydraulic fluid in the second section (8b) of the fluid line ( 8) is blocked and in a position of the rotor (3) in which the first control element (6) is in the link (11), the flow of hydraulic fluid in the second section (8 b) of the fluid line (8) releases, and wherein the second control element (7) in a position of the rotor (3), in which the second control element (7) is not in the link (11) blocks the flow of hydraulic fluid in the first section (8a) of the fluid line (8) and in a position of the rotor (3) in which the second control element (7) is in the slot (11) releases the flow of hydraulic fluid in the first section (8a) of the fluid line (8).

Description

Field of the invention

• - einen Stator, in dem ein Rotor drehbar angeordnet ist, wobei der Stator mindestens einen Flügel aufweist, wobei der Flügel in einer Hydraulikkammer des Stators angeordnet ist, so dass eine erste Teilkammer von einer zweiten Teilkammer getrennt wird,
• - ein Zentralventil, das den Strom von Hydraulikfluid in die erste Teilkammer und in die zweite Teilkammer steuert,
• - ein Verriegelungssystem, mit dem der Rotor relativ zum Stator in einer Mittenposition verriegelt werden kann, wobei das Verriegelungssystem ein erstes Steuerelement und ein zweites Steuerelement umfasst, die durch Beaufschlagung mit Hydraulikfluid über das Zentralventil in einer entsperrten Position gehalten werden können und die bei Wegnahme des Drucks des Hydraulikfluids eine Verriegelung veranlassen können, wobei das erste Steuerelement und das zweite Steuerelement mit einer Kulisse in Wirkverbindung gebracht werden können, die im Stator oder einem mit diesem verbundenen Bauteil ausgebildet ist, wobei die Kulisse eine axiale Lage des Steuerelements bestimmt,
• - eine Hydraulikpumpe zur Bereitstellung von Hydraulikfluid und
• - einen Tank zur Aufnahme von Hydraulikfluid, wobei - das Verriegelungssystem eine Fluidleitung umfasst, die in mindestens einen der Flügel eingearbeitet ist, wobei die Fluidleitung einen ersten Abschnitt aufweist, der einen Fluss von Hydraulikfluid von der ersten Teilkammer in die zweite Teilkammer zulässt, und einen zweiten Abschnitt aufweist, der einen Fluss von Hydraulikfluid von der zweiten Teilkammer in die erste Teilkammer zulässt, - wobei im ersten Abschnitt der Fluidleitung ein erstes Rückschlagventil angeordnet ist, das den Fluss von Hydraulikfluid von der ersten Teilkammer in die zweite Teilkammer zulässt und in die Gegenrichtung verhindert, und - wobei im zweiten Abschnitt der Fluidleitung ein zweites Rückschlagventil angeordnet ist, das den Fluss von Hydraulikfluid von der zweiten Teilkammer in die erste Teilkammer zulässt und in die Gegenrichtung verhindert.

The invention relates to a hydraulic camshaft adjuster, comprising

• a stator in which a rotor is rotatably arranged, the stator having at least one vane, wherein the vane is arranged in a hydraulic chamber of the stator, so that a first sub-chamber is separated from a second sub-chamber,
• a central valve which controls the flow of hydraulic fluid into the first sub-chamber and into the second sub-chamber,
• a locking system for locking the rotor relative to the stator in a central position, the locking system comprising a first control element and a second control element which can be held in an unlocked position by applying hydraulic fluid through the central valve and which acts to remove the rotor Pressure of the hydraulic fluid can cause a locking, wherein the first control element and the second control element can be brought into operative connection with a gate which is formed in the stator or a component connected thereto, wherein the gate determines an axial position of the control,
• a hydraulic pump for providing hydraulic fluid and
• a tank for receiving hydraulic fluid, wherein the locking system comprises a fluid conduit incorporated in at least one of the wings, the fluid conduit having a first portion allowing flow of hydraulic fluid from the first subchamber into the second subchamber, and second section, which allows a flow of hydraulic fluid from the second sub-chamber into the first sub-chamber, - wherein in the first portion of the fluid line, a first check valve is arranged, which allows the flow of hydraulic fluid from the first sub-chamber into the second sub-chamber and in the opposite direction prevents, and - wherein in the second portion of the fluid line, a second check valve is arranged, which allows the flow of hydraulic fluid from the second sub-chamber into the first sub-chamber and prevents in the opposite direction.

Background of the invention

A hydraulic camshaft adjuster of this kind is for example from the DE 10 2014 212 617 A1 known. Similar and other solutions show the DE 10 2012 211 870 A1 , the DE 10 2014 215 136 B4 , the DE 10 2014 223 020 B4 , the DE 10 2014 222 407 B4 , the DE 10 2015 209 313 A1 and the US 2014/0244141 A1 ,

In general, the use of such camshaft adjuster in all engines with variable valve timing makes sense. A center locking concept is used in particular in camshaft adjusters, with which, for example, an Atkinson cycle in the engine to be implemented. Here, the adjuster is not in one of the end positions of the adjustment, but in the locked center position between early and late adjustment at engine start. As a result, the starting ability is ensured at a cold start of the engine.

Here, it is provided that the camshaft adjuster be designed in such a way that with the aid of the camshaft alternating torques (ie on the basis of "CTA" = Cam Torque Activated), the center position also exists when the engine stops or starts the internal combustion engine, the rotor being actuated by means of a so-called hydraulic ratchet the center position is pulled.

For the aforementioned "CTA" operation different modes of action are known to bring the camshaft adjuster at engine stop in the center lock. On the one hand, the said hydraulic ratchet, on the other hand also a mechanical ratchet is used. Both principles of operation make use of the alternating torques of the camshaft and thus reach the center lock through the principle of a freewheel.

The complexity of the prior art midlock concepts in terms of the number of parts required and their installation have relatively high costs result, which makes the realization of a correspondingly equipped internal combustion engine more expensive.

The DE 10 2014 215 136 B4 shows a hydraulic camshaft adjuster, designed as a Flügelzellenversteller with which a phase angle of the camshaft relative to a crankshaft held or changed, the camshaft adjuster comprises a stator and a rotor and a control system, the pressure or hydraulic fluid with the interposition of a hydraulic valve and Connecting lines and hydraulic lines at least one pressure chamber feeds or discharges, wherein the pressure chambers are each divided by a rotor-fixed wing into separate, mutually acting, chamber pairings forming working chambers, wherein in at least one wing a control device is introduced, which is for selective release and interruption of a flow connection between the Working chambers is determined, and the switchable via an actuator Hydraulic valve comprises a plurality of work spans and connected to a pressure source P-port and a tank connected to a T-port and the rotor is a locking device is integrated, consisting of two axially adjustable, spring-loaded locking piston, if necessary, a relative movement between the rotor and prevent the stator, in which at least one locking piston from a first switching position against a spring force in a second switching position is displaceable and locked in a rotation of the rotor from a stop position FRUEH or SPAET in a center locking position (MVP) in a locking slot, each locking piston of Locking device has an axial bore, which each produce separate flow connections between the working chambers of a pressure chamber in a position match with a connecting line.

The DE 10 2014 205 568 A1 shows a camshaft adjusting device with a Flügelzellenversteller with a connectable to a crankshaft of an internal combustion engine stator and rotatably mounted in the stator, connectable to a camshaft rotor, wherein on the stator a plurality of webs are provided, which an annular space between the stator and the rotor in a plurality subdividing pressure chambers, the rotor having a rotor hub and a plurality of radially outwardly extending blades extending from the rotor hub, which subdivide the pressure chambers into two groups of working chambers with a different effective direction that can be acted upon in each case by a pressure medium flowing or flowing in a pressure medium circuit. and a center locking device for locking the rotor in at least one locking position relative to the stator, wherein the center locking device at least two spring-loaded Verr. Lockable in a stator-fixed locking link Having iegelungsstifte in a receiving space, which lock at a rotation of the rotor from a stop position "early" or "late" in the locking position from different directions in the locking link, wherein the locking pin with the respective receiving space forms a valve device, wherein the locking pin is a valve pin forms, wherein the valve pin is a stepped pin.

Object of the invention

The present invention has for its object to design a generic camshaft adjuster so that it is possible to realize in a simpler and thus cost-effective manner, the hydraulic center locking concept. This is to reduce the manufacturing and assembly costs and thus cost savings are possible.

Summary of the invention

The solution of this object by the invention is characterized in that the first control in a position of the rotor in which the first control is not in the backdrop blocked the flow of hydraulic fluid in the second section of the fluid line and in a position of the rotor, in which the first control is in the gate, releases the flow of hydraulic fluid in the second section of the fluid line, and wherein the second control in a position of the rotor, in which the second control is not in the gate, the flow of hydraulic fluid in the blocked first portion of the fluid line and in a position of the rotor, in which the second control is in the backdrop, the flow of hydraulic fluid in the first portion of the fluid line releases.

The two sections of the fluid line are preferably formed as straight holes in the wing. Preferably, the two sections of the fluid line intersect.

The check valves are preferably arranged in each case at the end of the sections of the fluid line adjacent to the partial chamber in the respective section of the fluid line.

In this case it can be provided that the check valves are formed as flat elements and arranged in each case a groove which extends in the wing in the direction of the axis of rotation of the camshaft adjuster.

Preferably, a single gate for both controls is arranged or provided.

The controls can be arranged in each case a bore in the rotor. They can each be designed as a pin, which is arranged against the bias of a spring in the bore in the rotor.

The gate preferably has an extension in the circumferential direction in the stator or in a component connected thereto which corresponds to the distance between the two control elements in the circumferential direction. It is preferably formed as a curved slot in the stator or a component connected thereto.

The proposed solution thus depends on the realization of a hydraulic freewheel, with bypasses between the two sub-chambers A and B (Supporting chambers) are created. This bypass between the support chambers is realized in the proposed concept by two check valves in the wing, which separates the support chambers from each other, as well as through holes from the check valves to the lock pins. The activation or deactivation of the bypasses (ie the closing or the release of the same) is caused by the locking pins.

Essential features of the proposed solution are thus the two check valves in one of the wings and adjoining the same by-pass channels.

The opening or the closing of the bypasses results from the interaction of the channels with the check valves and the locking piston (locking pins). There are no separate control piston required, which reduces the number of parts and thus the cost.

When the motor is switched off, the bypasses with the non-return valves between the support chambers and the corresponding circuit of the locking pins allow oil to be forced from the decreasing chamber into the larger one (the camshaft alternating moment acts towards the center).

Conversely, (i.e., the camshaft alternating moment acts away from the center, toward the end stop), no oil can flow due to the check valves.

The realization of the flow of oil through the wing by means of flow channels (bypass holes) and check valves is less expensive and thus more cost-effective than the previously known Midlock concepts.

The proposed solution creates a new realization possibility in a center-locking phaser. Furthermore, costs can be reduced because a simpler construction concept becomes possible. In particular, manufacturing costs and assembly costs are reduced because the number of parts can be reduced compared to previously known solutions.

Furthermore, there is a lower risk of leakage from the A / B subchambers into the C channel, since the length of the C channel is less. Thus, a conceivable Selbstentriegelung the locking piston due to pressure peaks from the A / B subchambers is unlikely.

list of figures

• 1 in der Vorderansicht einen Nockenwellenversteller, bei dem sich der Rotor relativ zum Stator in einer verriegelten Mittenposition befindet,
• 2 eine perspektivische Darstellung des Nockenwellenverstellers gemäß 1,
• 3 die Vorderansicht des Nockenwellenverstellers, wobei sich der Rotor desselben in einer „Spät“-Stellung befindet und wobei infolge eines Schleppmoments des Rotors in Richtung „Früh“ eine relative Verschiebung zwischen Rotor und Stator erfolgen kann,
• 4 den Schnitt C-C gemäß 3,
• 5 den Schnitt D-D gemäß 3,
• 6 die Vorderansicht des Nockenwellenverstellers, wobei sich der Rotor desselben in einer „Spät“-Stellung befindet und wobei infolge eines Schleppmoments des Rotors in Richtung „Spät“ keine relative Verschiebung zwischen Rotor und Stator erfolgen kann,
• 7 den Schnitt E-E gemäß 6 und
• 8 den Schnitt F-F gemäß 6.

In the figures, an embodiment of the invention is shown. Show it:

• 1 in the front view, a phaser, in which the rotor is in a locked center position relative to the stator,
• 2 a perspective view of the camshaft adjuster according to 1 .
• 3 the front view of the camshaft adjuster, wherein the rotor of the same is in a "late" position and wherein due to a drag torque of the rotor in the direction of "early" a relative displacement between the rotor and stator can take place,
• 4 the cut C - C according to 3 .
• 5 the cut D - D according to 3 .
• 6 the front view of the camshaft adjuster, wherein the rotor thereof is in a "late" position and wherein due to a drag torque of the rotor in the direction "late" no relative displacement between the rotor and stator can take place,
• 7 the cut e - e according to 6 and
• 8th the cut FF according to 6 ,

Detailed description of the figures

In the 1 and 2 is a camshaft adjuster 1 shown that a stator 2 and a relative to this rotatable rotor 3 having. The rotor 3 has (at least one) wings 4 , where the wing 4 in a hydraulic chamber 5 of the stator 2 extends into it and here a first sub-chamber A from a second sub-chamber B separates. In regular operation of the camshaft adjuster 1 is by supplying hydraulic oil in the sub-chambers A or. B (caused by a central valve, not shown) a desired relative rotational position between the stator 2 and rotor 3 manufactured. Not shown is a hydraulic pump ( P ) or a tank ( T ), as they are needed for the supply of pressure oil.

Hereinafter, only the new features of the hydraulic camshaft adjuster are shown, since the general operation of such a phaser is well known. For hydraulic control of such an element and in particular for controlling the adjuster with a central valve is expressly for example on the DE 10 2013 226 437 B4 the patent applicant, where detailed information is included.

In normal operation of the camshaft adjuster 1 Accordingly, the sub-chambers A and B supplied in the desired manner with hydraulic oil. A locking system 6 . 7 . 8th . 9 . 10 is passive in this operating mode, which is accomplished by placing in a C port (see the oil supply line 14 according to the same 1 ) Pressure oil is passed. This has the consequence that a first control 6 and a second control 7 such by means of the pressure of the hydraulic fluid against a spring 13 (see the 4 and 5 or. 7 and 8th ) pressed the controls 6 . 7 take a non-locked position and thus the camshaft adjuster 1 is in his normal working position.

For locking the camshaft adjuster 1 with the rotor 3 in a middle position M as they are in the 1 and 2 is shown, is the camshaft adjuster 1 provided with a special design that allows the drag torque (CTA = cam torque activated) between rotor 3 and stator 2 Make sure that the rotor 3 in said center position M is brought.

This includes the locking system 6 . 7 . 8th . 9 . 10 a fluid line 8th in one of the wings 4 is incorporated (see the 1 and 2 as well as the 3 and 6 ). The fluid line 8th has a first section 8a containing a flow of hydraulic fluid from the first subchamber A into the second compartment B allows; Further, a second section 8b present a flow of hydraulic fluid from the second sub-chamber B into the first compartment A allows.

In the first part 8a the fluid line 8th is a first check valve 9 arranged, which is the flow of hydraulic fluid from the first sub-chamber A into the second compartment B allows and prevents in the opposite direction. In the second section 8b the fluid line 8th is a second check valve 10 arranged, which is the flow of hydraulic fluid from the second sub-chamber B into the first compartment A allows and prevents in the opposite direction.

The check valves 9 and 10 are in grooves 12 (please refer 2 ) used in the wing 4 are incorporated.

The two controls 6 and 7 (Control pins) are on average in the 4 . 5 . 7 and 8th to see. You can change their axial position a against the action of a spring 13 change, which is initially dependent on whether in C -Port pressure is applied or not. Furthermore, the axial position of the controls 6 and 7 determined by whether they are in the field of a backdrop 11 reach in the housing cover of the stator 2 trained or incorporated there.

As can be seen from the sectional views according to the 4 and 5 or. 7 and 8th results cause the controls 6 or. 7 depending on their axial position, whether the respective section 8a or. 8b the fluid line 8th is released or blocked.

This is achieved by having the first control 6 in a position of the rotor 3 in which is the first control 6 not in the scenery 11 located, the flow of hydraulic fluid in the second section 8b the fluid line 8th blocked and in a position of the rotor 3 in which is the first control 6 in the scenery 11 located, the flow of hydraulic fluid in the second section 8b the fluid line 8th releases (when the pressure in the C -Port is taken away).

Accordingly, the second control 7 in a position of the rotor 3 in which is the second control 7 not in the scenery 11 located, the flow of hydraulic fluid in the first section 8a the fluid line 8th blocked and in a position of the rotor 3 in which is the second control 7 in the scenery 11 located, the flow of hydraulic fluid in the first section 8a the fluid line 8th releases (if the pressure in the C-port is removed).

With reference to 3 can be seen that here a drag torque on the rotor 3 is exercised, which this from the illustrated "late" position towards the desired center position M would turn. This can in the illustrated position of the controls 6 and 7 done: The control 7 is located in the 5 shown position in which a fluid flow through the second section 8b the fluid line 8th can take place (see the indicated flow path in 3 ). Accordingly, fluid from the sub-chamber A in the sub-chamber B flow and so does the rotor 3 be rotated in the direction of the center position (in the other hydraulic chambers is through the central valve, a short circuit between the sub-chambers A and B manufactured, s. the here entered arrows of the hydraulic flow, so that said rotation of the rotor 3 not hindered). The first control 6 is here in the 4 shown position and not yet in the engagement area of the backdrop 11 ,

Acts the drag torque on the rotor in the other direction, as in 6 implied, the rotor would 3 pushed from the illustrated "late" position even further to late-stop. However, this is prevented by the fact that despite the opened first section 8a the fluid line 8th (see position of the second control 7 ) the check valve 9 the return flow through the fluid line from the sub-chamber B in the sub-chamber A prevented.

Thus, the drag moments between rotor act 3 and stator 2 so long in the way described until the rotor 3 in the middle position M has moved and can lock here, since then both controls 6 and 7 in the field of scenery 11 (this condition is in the 1 and 2 reached and shown).

Accordingly, the "cam torque activated" (CTA) operation is readily implemented to drive the rotor 2 in the middle position M bring to.

LIST OF REFERENCE NUMBERS

1

Phaser

2

stator

3

rotor

4

wing

5

hydraulic chamber

6, 7, 8, 9, 10

locking system

6

first control (control pin)

7

second control (control pin)

8th

fluid line

8a

first section of the fluid line

8b

second section of the fluid line

9

first check valve

10

second check valve

11

scenery

12

groove

13

feather

14

Oil supply line C -Port

A

first compartment

B

second sub-chamber

C

C -Port for unlocking

P

hydraulic pump

T

tank

a

axial position

M

center position

Claims (10)

A hydraulic phaser (1) comprising - a stator (2) in which a rotor (3) is rotatably mounted, said stator (2) having at least one vane (4), said vane (4) being mounted in a hydraulic chamber (5 ) of the stator (2) is arranged so that a first sub-chamber (A) is separated from a second sub-chamber (B), - a central valve, the flow of hydraulic fluid in the first sub-chamber (A) and in the second sub-chamber (B a locking system (6, 7, 8, 9, 10) with which the rotor (3) can be locked relative to the stator (2) in a central position (M), the locking system (6, 7, 8 , 9, 10) comprises a first control element (6) and a second control element (7) which can be held in an unlocked position by applying hydraulic fluid (C) via the central valve and which can cause locking upon removal of the pressure of the hydraulic fluid , wherein the first control element (6) and the second control element ement (7) can be brought into operative connection with a link (11) which is formed in the stator (2) or a component connected thereto, the link (11) having an axial position (a) of the control element (6, 7) - a hydraulic pump (P) for providing hydraulic fluid and - a tank (T) for receiving hydraulic fluid, wherein the locking system (6, 7, 8, 9, 10) comprises a fluid line (8) which in at least one of Wing (4) is incorporated, wherein the fluid line (8) has a first portion (8a), which allows a flow of hydraulic fluid from the first sub-chamber (A) in the second sub-chamber (B), and a second portion (8b) , which allows a flow of hydraulic fluid from the second sub-chamber (B) into the first sub-chamber (A), wherein in the first portion (8a) of the fluid line (8) a first check valve (9) is arranged, which controls the flow of hydraulic fluid from the first sub-chamber (A) in the second sub-chamber (B) zul and in the opposite direction, wherein in the second portion (8b) of the fluid line (8) a second check valve (10) is arranged, which allows the flow of hydraulic fluid from the second sub-chamber (B) in the first sub-chamber (A) and in prevents the opposite direction, characterized in that the first control element (6) in a position of the rotor (3) in which the first control element (6) is not in the link (11), the flow of hydraulic fluid in the second section (8b ) of the fluid line (8) and in a position of the rotor (3) in which the first control element (6) in the link (11), the flow of hydraulic fluid in the second section (8b) of the fluid line (8) releases , and wherein the second control element (7) in a position of the rotor (3), in which the second control element (7) is not in the link (11), the flow of hydraulic fluid in the first portion (8a) of the fluid line (8 ) and in a position of the rotor (3), in which the second control element (7) is in the slot (11), the flow of hydraulic fluid in the first portion (8a) of the fluid line (8) releases. Hydraulic camshaft adjuster (1) to Claim 1 , characterized in that the two portions (8a, 8b) of the fluid line (8) are formed as straight holes in the wing (4). Hydraulic camshaft adjuster (1) to Claim 1 or 2 , characterized in that the two sections (8a, 8b) of the fluid line (8) intersect. Hydraulic camshaft adjuster (1) according to one of Claims 1 to 3 , characterized in that the check valves (9, 10) respectively at the end of the portions (8a, 8b) of the fluid line (8) adjacent to the sub-chamber (A, B) in the respective section (8a, 8b) of the fluid line (8) are arranged , Hydraulic camshaft adjuster (1) to Claim 4 , characterized in that the check valves (9, 10) formed as flat elements and in each case a groove (12) are arranged, which extends in the wing (4) in the direction of the axis of rotation of the camshaft adjuster (1). Hydraulic camshaft adjuster (1) according to one of Claims 1 to 5 , characterized in that a single link (11) for both controls (6, 7) is arranged. Hydraulic camshaft adjuster (1) according to one of Claims 1 to 6 , characterized in that the control elements (6, 7) in each case a bore in the rotor (3) are arranged. Hydraulic camshaft adjuster (1) to Claim 7 , characterized in that the control elements (6, 7) are each formed as a pin which is arranged against the bias of a spring (13) in the bore in the rotor (3). Hydraulic camshaft adjuster (1) according to one of Claims 1 to 8th , characterized in that the link (11) in the stator (2) or in a component connected thereto has an extension in the circumferential direction, which corresponds to the distance between the two control elements (6, 7) in the circumferential direction. Hydraulic camshaft adjuster (1) according to one of Claims 1 to 9 , characterized in that the link (11) is formed as a curved slot in the stator (2) or a component connected thereto.

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