DE102017126174A1 - 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), wherein the wing (4) 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 (6), the flow of hydraulic fluid into the first sub-chamber (A) and in the second sub-chamber (B) controls a locking system (7, 8) with which the rotor (3) can be locked relative to the stator (2) in a central position (M), the locking system (7, 8) being a first control element (7) which can be held in an unlocked position by the application of hydraulic fluid (C) via the central valve (6) and which can cause a lock when the pressure of the hydraulic fluid is removed, the first control element (7) being provided with a guide (7). 9) brought into operative connection who can, which is formed in the stator (2) or a component connected thereto, wherein the link (9) determines an axial position (a) of the first control element (7), a hydraulic pump (P) for providing hydraulic fluid and a tank (T) for receiving hydraulic fluid. In order to increase the dynamics of the camshaft adjuster when assuming the center position, the invention provides that the first control element (7) adjoins a first flow channel (10) in the rotor (3) which is a fluidic to a subchamber (A, B) Connection is achieved, wherein the first flow channel (10) can be opened or closed depending on the axial position of the first control element (7) and wherein from the first control element (7) a first opening (11) through the rotor (3) in the direction of tank ( T) leads.

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 umfasst, das durch Beaufschlagung mit Hydraulikfluid über das Zentralventil in einer entsperrten Position gehalten werden kann und das bei Wegnahme des Drucks des Hydraulikfluids eine Verriegelung veranlassen kann, wobei das erste Steuerelement mit einer Kulisse in Wirkverbindung gebracht werden kann, die im Stator oder einem mit diesem verbundenen Bauteil ausgebildet ist, wobei die Kulisse eine axiale Lage des ersten Steuerelements bestimmt,
• - eine Hydraulikpumpe zur Bereitstellung von Hydraulikfluid und
• - einen Tank zur Aufnahme von Hydraulikfluid.

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 with which the rotor can be locked relative to the stator in a central position, the locking system comprising a first control member which can be held in an unlocked position by the application of hydraulic fluid through the central valve and when the pressure of the hydraulic fluid is removed Lock can cause, wherein the first control 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 first control,
• a hydraulic pump for providing hydraulic fluid and
• - A tank for holding hydraulic fluid.

Background of the invention

A hydraulic camshaft adjuster of this kind is for example from the DE 10 2012 201 556 B4 known. Similar and other solutions show the DE 10 2012 201 570 A1 , the DE 10 2012 201 551 A1 , the US 2003/196626 A1 , the US 2011/017156 A1 and the US 2013/220253 A1 , Part of such cam phasers is to provide a locking function in the central position of the rotor blade in the hydraulic chamber, and this should be possible in a reliable and inexpensive manner.

It is known to design camshaft adjusters in such a way that with the aid of the camshaft alternating torques (ie on the basis of "CTA" = Cam Torque Activated; also available when stopping the engine), the center position is also present when the engine stops or starts the internal combustion engine Rotor is pulled by means of a so-called hydraulic ratchet in the center position. The hydraulic ratchet is also combined with the so-called "smart phasing" function, as components for both functions can be used simultaneously, which provides cost advantages. This is also known as a "smart lock".

The aforementioned "Smart Lock" function provides cost advantages over a simple "Midlock" manufacturer. However, it is necessary for hydraulic oil in the rotor (as from the above DE 10 2012 201 566 B2 and from the DE 10 2012 201 570 A1 known) or by means of a collecting bell (as from the above DE 10 2012 201 551 A1 known) in the spring cover store. Since the stored oil can no longer be used for the hydraulic ratchet function due to the then high oil viscosity (and the resulting flow resistance through the check valve inlets of the vane), this is combined with a simple mechanical ratchet function. This then jumps as a "fail-safe" function, for example, when the engine was shut down after stalling unlocked and the oil then reaches a high viscosity at low ambient temperature.

When using the oil pressure of the hydraulic pump in the so-called "Oil Pressure Activated" operation for starting the center position of the engine is stopped, remains for the camshaft adjuster only a short time window from switching off the ignition until the disappearance of the pump pressure to come to the center position. Typically, these are only a few tenths of a second. The camshaft adjuster is commanded to drive to the center by the central valve in the base position shorts the working chambers and vented the C-channel. As a result, depending on the position, one of the locking pins can retract. Mostly the rotor is at a position outside the center position at this time. The smaller Midlock chamber (eg subchamber "B") is supplied with oil by the pump. The larger chamber (eg, the sub-chamber "A") must now be emptied quickly and oppose as little as possible the inflation of the other chamber.

The problem is that in the short time available sometimes insufficient hydraulic fluid from the camshaft adjuster via the central valve (which is connected to the tank) can be dissipated, so that can not always be ensured that the required center position is reliably achieved.

Object of the invention

The present invention is therefore the object of a generic camshaft adjuster in such a way that it is possible to approach the center position of the camshaft adjuster in a reliable manner in the short time while oil pressure is still available. Around To achieve this, the dynamics of the camshaft adjuster should be increased when taking the center position.

Summary of the invention

The solution of this problem by the invention is characterized in that the first control adjacent to a first flow channel in the rotor, which creates a fluidic connection to a sub-chamber, wherein the first flow channel can be opened or closed depending on the axial position of the first control and wherein from the first control a first opening through the rotor leads in the direction of the tank.

Preferably, the locking system further comprises a second control member which can be held in an unlocked position by applying hydraulic fluid through the central valve and which can cause locking upon removal of the pressure of the hydraulic fluid, whereby the second control member can be engaged with the linkage. wherein the gate defines an axial location of the second control, the second control adjacent to a second flow channel in the rotor creating a fluidic connection to the other of the sub-chambers, the second flow channel being opened or closed depending on the axial location of the second control can and wherein the second control element performs a second opening through the rotor in the direction of the tank.

The cross section of the first flow channel and / or of the second flow channel is preferably between 1 mm ² and 30 mm ² , more preferably between 7.5 mm ² and 15 mm ² . Preferably, the cross section of the first opening and / or the second opening is between 1 mm ² and 30 mm ² , more preferably between 7.5 mm ² and 15 mm ² .

The gate, according to a possible embodiment of the invention has a contact surface for the first and optionally the second control, which has a linear course. In this case, it is preferably provided that the slide has a floor running at a constant distance from the rotor.

According to another preferred embodiment of the invention, the slide on a contact surface for the first and optionally the second control, which has a non-linear course. In this case, it is preferably provided that the slide has at least one floor running at a constant distance from the rotor and at least one ramp adjoining the floor. In particular, it can be provided that the scenery has two ramps that connect to the two sides of the soil. Hereby, the backdrop can make a targeted rotorpositionsbezoge throttling the hydraulic flow rate.

The first flow channel and / or the second flow channel preferably run parallel to a further flow channel, via which hydraulic fluid for normal operation of the camshaft adjuster is passed.

The backdrop is preferably formed as a curved slot in the stator or a component connected thereto.

The controls are preferably designed as a pin which is arranged against the bias of a spring in a bore in the rotor.

According to a preferred further embodiment, it is provided that the stator or a component connected to it has segments which increase or attenuate the ventilation to the tank along the possible adjustment positions.

Thus, the proposed concept is based on an oil-pressure-activated starting of the center position, wherein a special design for a quick oil removal is proposed for improved locking.

It illustrates one possible circuit of center-locking oil pressure-activated start-up of the center position, and the proposed specific design for quick oil drainage can be applied across the board for improved interlocking.

The proposed concept thus restricts not, as usual, to direct the hydraulic oil of the chamber to be reduced to the T-port of the central valve. Due to the necessary design of the central valve ("sequence control") for stable hydraulic clamping of the camshaft adjuster and the tight space can there a certain cross-sectional area for the discharge of the oil to the tank are not exceeded.

Therefore, in order to improve the dynamics of the camshaft phaser, it is proposed to direct the hydraulic fluid in midlock operation directly out of the mid-position-approaching sub-chambers (i.e., from the "midlock chambers"), without passing over the valve, out of the phaser.

According to a development of the invention, it is proposed to selectively throttle the discharge of the oil via this direct path (preferably position-dependent) in order to preserve the mechanics of the adjuster.

list of figures

• 1 schematisch einen Nockenwellenversteller mit einer möglichen Schaltung einer Öldruck-aktivierten Mittenverriegelung mit seiner hydraulischen Versorgung, wobei der Verriegelungsvorgang in eine Mittenposition aus einer „Spät“-Stellung dargestellt ist,
• 2 schematisch den Schnitt durch den Nockenwellenversteller, wobei der zu 1 korrespondierende Zustand gezeigt ist,
• 3 einen Schnitt durch einen Abschnitt des Nockenwellenverstellers, wobei der in der Mittenposition verriegelte Zustand dargestellt ist,
• 4 einen Schnitt durch einen Abschnitt des Nockenwellenverstellers gemäß 3, wobei der nicht verriegelte Zustand (Normalbetrieb des Nockenwellenverstellers) dargestellt ist,
• 5 in perspektivischer Darstellung den Rotor des Nockenwellenverstellers, wobei die Fließwege des Hydraulikfluids dargestellt sind,
• 6 in perspektivischer Darstellung einen Abschnitt des Nockenwellenverstellers,
• 7 eine Darstellung analog zu 3, wobei eine spezielle Ausgestaltung der Kulisse für die Verriegelung der Steuerelemente dargestellt ist, und
• 8 in perspektivischer Darstellung den Nockenwellenversteller mit transparenter Darstellung eines speziell ausgestalteten Deckels des Stators (Dichtdeckel), wobei die Mittenposition des Rotors relativ zum Stator dargestellt ist; in dieser Figur sind noch zwei entsprechende Darstellungen des Nockenwellenverstellers außerhalb der Mittelposition zu sehen.

In the figures, embodiments of the invention are shown. Show it:

• 1 1 schematically shows a camshaft adjuster with a possible connection of an oil pressure-activated center lock with its hydraulic supply, wherein the locking process is shown in a middle position from a "late" position,
• 2 schematically the section through the camshaft adjuster, wherein the 1 corresponding state is shown
• 3 a section through a portion of the camshaft adjuster, wherein the locked in the center position state is shown,
• 4 a section through a portion of the camshaft adjuster according to 3 , wherein the unlocked state (normal operation of the camshaft adjuster) is shown,
• 5 in a perspective view of the rotor of the camshaft adjuster, wherein the flow paths of the hydraulic fluid are shown,
• 6 in a perspective view a portion of the camshaft adjuster,
• 7 a representation analogous to 3 , wherein a special embodiment of the gate for the locking of the controls is shown, and
• 8th in a perspective view of the camshaft adjuster with transparent representation of a specially designed cover of the stator (sealing cover), wherein the center position of the rotor is shown relative to the stator; in this figure are still two corresponding representations of the camshaft adjuster outside the center position to see.

Detailed description of the figures

From the synopsis of 1 and 2 is a camshaft adjuster 1 it can be seen that a stator 2 and a relative to this rotatable rotor 3 having. The rotor 3 has several wings 4 which is in respective hydraulic chambers 5 of the stator 2 extend and here in each case a first sub-chamber A from a second sub-chamber B separate. In regular operation of the camshaft adjuster 1 is by supplying hydraulic oil through a central valve 6 in the sub-chambers A or. B a desired relative rotational position between stator 2 and rotor 3 manufactured.

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 7 . 8th , is passive in this mode of operation, which is accomplished by passing pressurized oil into a C port. As a result, controls 7 . 8th such by means of the pressure of the hydraulic fluid against a spring 16 pressed that controls 7 . 8th take a non-locked position and thus the camshaft adjuster 1 is in his normal working position.

From the 1 and 2 It can also be seen how to proceed to the rotor 3 relative to the stator 2 in the middle position M to spend (in 8th is shown) and lock there.

The locking itself takes place through a backdrop 9 placed in a lid of the stator 2 is incorporated. Once the pressure in the C-port has been removed and the prerequisite for locking is created, the controls can 7 . 8th with appropriate relative position between stator 2 and rotor 3 in the scenery 9 due to the action of the spring 16 engage and thus cause the lock. For this, however, the rotor must 3 first in the middle position M to be brought.

The central valve 6 is this in the in 1 shown position ("midlock" position) switched. The sub-chambers A and B are shorted in this position and the C port on the tank T switched to locking the controls 7 . 8th to make possible.

The two controls 7 and 8th can do both in 1 take shown switching positions, depending on the axial position a that from the backdrop 9 is determined.

Out 1 it can be seen that the rotor 3 relative to the stator 2 is in a "late" position and accordingly for locking in the middle position M "Back" must be turned. The (even when stopping the engine for a short time) in the hydraulic pump P existing pressure acts due to the switching position of the control 7 on the sub-chamber B and thus causes the said required rotation of the rotor 3 so that the middle position M can be approached.

It is essential that provisions are made that a sufficiently rapid outflow of hydraulic fluid from the sub-chambers A . B can be done. How this is to be done according to the present proposal follows from the others 3 to 8th ,

The first control 7 for this purpose borders on a first flow channel 10 in the rotor 3 to the partial chamber B creates a fluidic connection. The first flow channel 10 depends on the axial position a of the first control 7 open or closed, taking from the first control 7 a first opening 11 through the rotor 3 towards the tank T leads.

Analog borders also the second control 8th to a second flow channel 12 in the rotor 3 to the partial chamber A creates a fluidic connection. The second flow channel 12 depends on the axial position a of the second control 8th open or closed, with the second control 8th a second opening 13 through the rotor 3 towards the tank T leads.

The two mentioned flow channels 10 and 12 go there - like out 5 can be seen - parallel to other flow channels 14 and 15 , is passed through the hydraulic fluid for normal operation of the camshaft adjuster. Meanwhile, the two flow channels lead 10 and 12 directly to the vent to the tank T (See also this 6 ).

A gentle initiation of the controls 7 . 8th in the locked position is by a special design of the backdrop 9 possible. This is in 7 shown. After that, there is the scenery 9 from a middle area with a floor 9 ' , on both sides of two ramps 9 " connect. If a control 7 . 8th in the area of the backdrop 9 reaches, the opening becomes 10 or. 12 in the course of the ramp in cross section increasingly reduced. As a result, the hydraulic fluid volume flow is throttled and the relative rotation of the rotor to the stator is delayed in a position-dependent manner.

Thus, the following can be said in total:

The direct discharge of the oil takes place (instead of in the previously known manner via the central valve to the tank) via an additional (radial) bore, which does not open into the T-port, but runs into the locking pin hole. The locking pin 7 . 8th releases said hole depending on position in midlock operation. The oil can now behind the locking pin 7 . 8th run and step over the recesses ( 11 or. 13 ) of the cartridge. The cross-sectional areas of the radial bore and the recesses of the cartridge are preferably approximately equal. A slight back pressure on the cartridge is not detrimental, as this helps the locking pin 7 . 8th to hold in position. Due to the low flow resistance can now be locked fast.

At high moments, the pins can 7 . 8th are mechanically heavily impacted when hitting the end of the scenery. Therefore, it is proposed according to a preferred embodiment of the invention to decelerate by selectively throttling the process, the movement during locking to a necessary level (see this particular 7 where the pins 7 . 8th locked with throttling are shown).

This happens in the embodiment in that the pin 7 . 8th on a flatter backdrop or in the middle position by means of ramps flattened locking link 9 running. With the backdrop 9 with ramps 9 " The locking speed is specifically maximized at an initially distant position and braked shortly before the impact of the locking pins. This can also be done via the throttling of the cartridge outlet. This is done by the with the stator 2 firmly connected sealing cover 17 with the attached sealing lid segments 18 (S. 8th ) accomplished. They throttle in the middle position the process.

LIST OF REFERENCE NUMBERS

1

Phaser

2

stator

3

rotor

4

wing

5

hydraulic chamber

6

central valve

7, 8

locking system

7

first control (control pin)

8th

second control (control pin)

9

scenery

9 '

Ground of the backdrop

9 ''

Ramp the backdrop

10

first flow channel

11

first opening

12

second flow channel

13

second opening

14

further flow channel (for normal operation)

15

further flow channel (for normal operation)

16

feather

17

sealing cover

18

Sealing cover segments

A

first compartment

B

second sub-chamber

C

C-port for unlocking

P

hydraulic pump

T

tank

M

center position

a

axial direction

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 102012201556 B4 [0002]
• DE 102012201570 A1 [0002, 0004]
• DE 102012201551 A1 [0002, 0004]
• US 2003196626 A1 [0002]
• US 2011017156 A1 [0002]
• US 2013220253 A1 [0002]
• DE 102012201566 B2 [0004]
• DE 102013226437 B4 [0024]

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 (6), the flow of hydraulic fluid in the first sub-chamber (A) and in the second Partial chamber (B) controls, - a locking system (7, 8) with which the rotor (3) relative to the stator (2) in a center position (M) can be locked, wherein the locking system (7, 8) a first control ( 7), which can be held in an unlocked position by the application of hydraulic fluid (C) via the central valve (6) and which can cause a lock when the pressure of the hydraulic fluid is removed, the first control element (7) being provided with a link (9 ) can be brought into operative connection in the stator (2) or a component connected thereto, wherein the link (9) determines an axial position (a) of the first control element (7), - a hydraulic pump (P) for providing hydraulic fluid and - a tank (T) for Receiving hydraulic fluid, characterized in that the first control element (7) adjacent to a first flow channel (10) in the rotor (3), which to a partial chamber (A, B) creates a fluidic connection, wherein the first flow channel (10) dependent from the axial position of the first control element (7) can be opened or closed and wherein the first control element (7) a first opening (11) through the rotor (3) in the direction of the tank (T) leads. Hydraulic camshaft adjuster to Claim 1 characterized in that the locking system (7, 8) further comprises a second control member (8) which can be held in an unlocked position by pressurization with hydraulic fluid (C) via the central valve (6) upon removal of the pressure of the hydraulic fluid a locking can be caused, wherein the second control element (8) with the link (9) can be brought into operative connection, wherein the link (9) determines an axial position (a) of the second control element (8), wherein the second control element (8 ) adjoins a second flow channel (12) in the rotor (3) which creates a fluidic connection to the other of the subchambers (A, B), the second flow channel (12) being opened depending on the axial position of the second control element (8) or can be closed by the second control element (8), a second opening (13) through the rotor (3) in the direction of the tank (T). Hydraulic camshaft adjuster to Claim 1 or 2 , characterized in that the cross section of the first flow channel (10) and / or the second flow channel (12) is between 1 mm ² and 30 mm ² , preferably between 7.5 mm ² and 15 mm ² . Hydraulic camshaft adjuster according to one of the Claims 1 to 3 , characterized in that the cross section of the first opening (11) and / or the second opening (13) is between 1 mm ² and 30 mm ² , preferably between 7.5 mm ² and 15 mm ² . Hydraulic camshaft adjuster according to one of the Claims 1 to 4 , characterized in that the link (9) has a contact surface for the first and optionally the second control element (7, 8), which has a non-linear course. Hydraulic camshaft adjuster to Claim 5 , characterized in that the link (9) at least one with a constant distance from the rotor (3) extending bottom (9 ') and at least one of the bottom (9') subsequent ramp (9 "). Hydraulic camshaft adjuster to Claim 6 , characterized in that the link (9) has two ramps (9 ") which adjoin the two sides of the bottom (9 '). Hydraulic camshaft adjuster according to one of the Claims 1 to 7 , characterized in that the first flow channel (10) and / or the second flow channel (12) parallel to a further flow channel (14, 15) extend, is passed over the hydraulic fluid for normal operation of the camshaft adjuster. Hydraulic camshaft adjuster according to one of the Claims 1 to 8th , characterized in that the link (9) is formed as a curved slot in the stator (2) or a component connected thereto. Hydraulic camshaft adjuster according to one of the Claims 1 to 9 , characterized in that the control elements (7, 8) are designed as a pin which is arranged against the bias of a spring (16) in a bore in the rotor (3).

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