DE102004049123A1 - Device for changing the timing of gas exchange valves of an internal combustion engine - Google Patents

Abstract

The The invention relates to a device (101) for modification the timing of gas exchange valves of an internal combustion engine with a hydraulic actuator (102) and a control valve (103). The device according to the invention (101) is with a center position lock of a hydraulic actuator (102). Continue to be guaranteed the device according to the invention (101) that in case of failure of an actuator (112), the control valve (103) controls the hydraulic actuator (102) in the center position is locked and the lock until the repair of the actuator (112) is held. Furthermore, the device according to the invention allows (101) starting the internal combustion engine in a locked position in a center position, without that at the start of the internal combustion engine a movable element (105) of the hydraulic actuator (102) strikes against a side wall of a pressure chamber (104). It will Method proposed to restart the actuator (102) bring the internal combustion engine in a locked center position and keep there.

Description

Territory of invention

The The invention relates to a device for changing the timing of Gas exchange valves of an internal combustion engine according to the preambles the claims 1, 2 and 3.

In Internal combustion engines are used to actuate the gas exchange valves Camshafts used. Camshafts are such in the internal combustion engine mounted on cams attached to cam followers, for example, bucket tappets, drag levers or rocker arms, abut. If a camshaft is set in rotation, so roll the cams on the cam followers, which in turn the gas exchange valves actuate. Due to the position and shape of the cams are thus both the opening duration as well as the opening amplitude but also the opening and closing times the gas exchange valves set.

modern Engine concepts go to make the valve train variable. On the one hand, valve lift and valve opening duration should be variable be until the complete shutdown of individual cylinders. That's what concepts are for such as switchable cam followers or electro-hydraulic or electric valve actuators intended. Furthermore, it has proved to be advantageous while the operation of the internal combustion engine affects the opening and closing times to be able to take the gas exchange valves. It is in particular desirable the opening or closing times the inlet or Separate valves to be able to influence separately, for example, targeted a defined valve overlap adjust. By setting the opening and closing times the gas exchange valves in dependence from the current engine map of the engine, for example, the current Speed or the current load, the specific fuel consumption lowered, the exhaust gas behavior positively influenced, the engine efficiency, the maximum torque and the maximum power are increased.

The described variability the valve timing is determined by a relative change in the phase angle of Camshaft to crankshaft reached. This is the camshaft mostly over a chain, belt, gear drive or equivalent drive concepts in drive connection with the crankshaft. Between that of the Crankshaft driven chain, belt or gear drive and The camshaft is a device for changing the timing of a Internal combustion engine, also called camshaft adjuster below, attached, which transmits the torque from the crankshaft to the camshaft. there this device is designed such that during operation of the internal combustion engine the phase angle between crankshaft and camshaft held securely and, if desired, the camshaft in a certain angular range with respect to the Crankshaft can be rotated.

In Internal combustion engines, each with a camshaft for the intake and the exhaust valves can this each equipped with a camshaft adjuster. This allows the opening and closing times the intake and exhaust valves shifted in time relative to each other and the valve overlaps be targeted.

Of the Location of modern camshaft adjuster is usually located on the drive side End of the camshaft. The camshaft adjuster can also on an intermediate shaft, a non-rotating component or the Crankshaft be arranged. It consists of one of the crankshaft driven, a fixed phase relation to this holding drive wheel, a driven part in drive connection with the camshaft and one transmitting the torque from the drive wheel to the output member Adjustment mechanism. The drive wheel can not in case of one the crankshaft arranged camshaft adjuster chain, Belt or gear executed be and is by means of a chain, a belt or a gear drive driven by the crankshaft. The adjustment mechanism can be electrical, operated hydraulically or pneumatically.

Two preferred embodiments hydraulically adjustable camshaft adjusters provide the so-called Axialkolbenversteller and Rotationskolbenversteller dar.

at the Axialkolbenverstellern is the drive wheel with a piston and this with the output member via helical gears in combination. The piston separates one by the driven part and the drive wheel formed cavity in two axially mutually arranged pressure chambers. If now the one pressure chamber is acted upon with pressure medium, while the other pressure chamber is connected to a tank, so shifts the piston in the axial direction. The axial displacement of the Piston is caused by the helical gears in a relative rotation of the drive wheel to the output part and thus the camshaft translates to the crankshaft.

A second embodiment of hydraulic phaser are the so-called rotary piston adjuster. In these, the drive wheel is rotatably connected to a stator. The stator and a rotor are arranged concentrically to one another, wherein the rotor is positively, positively or materially, for example by means of a press fit, a screw or welded joint is connected to a camshaft, an extension of the camshaft or an intermediate shaft. In the stator, a plurality of circumferentially spaced cavities are formed which extend radially outward from the rotor. The cavities are limited pressure-tight in the axial direction by side cover. In each of these cavities, a wing connected to the rotor extends, dividing each cavity into two pressure chambers. By selectively connecting the individual pressure chambers with a pressure medium pump or with a tank, the phase of the camshaft can be adjusted or held relative to the crankshaft.

to Control of the camshaft adjuster sensors capture the characteristics of the engine, such as the load condition and the speed. These Data is fed to an electronic control unit which after comparing the data with a characteristic field of the internal combustion engine the inflow and outflow of pressure medium to the various pressure chambers controls.

Around to adjust the phasing of the camshaft relative to the crankshaft is one of the two in hydraulic camshaft adjusters against each other acting pressure chambers of a cavity with a pressure medium pump and the other connected to the tank. The inflow of pressure medium to a chamber in connection with the discharge of pressure medium from the another chamber moves the pressure chambers separating piston in the axial direction, whereby Axialkolbenverstellern on the helical gears the camshaft is rotated relative to the crankshaft. In rotary piston adjusters is due to the pressurization of a chamber and the pressure relief the other chamber a displacement of the wing and thus directly one Rotation of the camshaft causes the crankshaft. To the phase position To hold both pressure chambers are either connected to the pressure medium pump or separated from both the pressure medium pump and the tank.

The Control of the pressure medium flows to or from the pressure chambers by means of a control valve, usually a 4/3 proportional valve. A valve housing is each with a connection for the pressure chambers (Working connection), a connection to the pressure medium pump and at least provided a connection to a tank. Within the essentially hollow cylindrical running valve housing an axially displaceable control piston is arranged. The control piston can by means of an electromagnetic actuator against the Spring force of a spring element axially in any position between two defined end positions are brought. The control piston is still on provided with annular grooves and control edges, whereby the individual pressure chambers optionally connected to the pressure medium pump or the tank can. Likewise, a position of the control piston may be provided, in the pressure medium chambers of both the pressure medium pump and are separated from the pressure tank.

In the DE 100 64 222 A1 such a device is shown. This is a device in rotary piston design. A standing in drive connection with the camshaft stator is rotatably mounted on a rotatably connected to a camshaft rotor. The stator is formed with recesses open to the rotor. In the axial direction of the device side covers are provided, which limit the device. The recesses are pressure sealed by the rotor, the stator and the side cover and thus form pressure chambers. In the outer circumferential surface of the rotor axial grooves are introduced, in which wings are arranged which extend into the recesses. The wings are designed such that they divide the pressure chambers into two oppositely acting pressure chambers. By supplying or discharging pressure medium to and from the pressure chambers, the phase position of the camshaft can be selectively held or adjusted relative to the crankshaft.

In the side covers two locking pins are arranged, which are acted upon by means of a spring means with a force in the direction of the rotor. In the end face of the rotor, which faces the locking pins, circumferentially extending grooves are mounted. The grooves are arranged and designed such that in a defined middle position, both locking pins engage in a respective groove when none of the grooves is acted upon by pressure medium. Each pin abuts a peripheral end of the respective groove. The rotor is thus locked relative to the stator whereby a relative rotation is prevented. About first and second pressure medium lines, the pressure medium chambers can be filled with pressure medium. If a first pressure medium chamber filled with pressure medium, so also an end face of a locking pin is acted upon with pressure medium. As a result, the corresponding pin is pressed into the receiving bore of the side cover and allows an adjustment of the rotor relative to the stator in one direction. In this case, the other groove in which the other Verrieglungspin still engages, designed such that an adjustment of the rotor from the center position is made possible up to a maximum value. Accordingly, the adjustment of the rotor relative to the stator runs in the other direction. The device is equipped with a compensation spring, which is attached at its one end to the rotor and at the other end to the stator and the drag torque, which the camshaft on balancing the rotor.

In DE 198 53 670 A1 a control valve is shown which serves to control the flow of pressure medium to the pressure chambers depending on the current load state of the internal combustion engine. The control valve consists of an actuating unit, a substantially hollow cylindrical valve housing and a substantially hollow cylindrical control piston, which is received axially displaceable within the valve housing. On the valve housing two working ports, an inlet and a drain port are formed. The adjusting unit can be, for example, an electromagnet, which shifts the control piston against the force of a spring by applying a control current via a push rod. Depending on the position of the control piston inside the valve housing, the inlet connection is connected to one of the two working connections and the tank connection to the other working connection or the working connections are disconnected from the inlet or outlet connection. As a result, pressure medium is supplied to a pressure chamber, while pressure medium flows out of the other pressure chamber, which causes a change in the phase position of the camshaft to the crankshaft.

One serious disadvantage of this control valve in conjunction with a Camshaft adjuster with center-position lock is the fact that in the de-energized state of the pressure medium connection with a the two work connections connected is. in case of malfunction of the actuator is So pressure medium to one of the two pressure chambers and at the same time directed to one of the two pins. This will cause the camshaft adjuster, dependent from the configuration of the control valve, after failure of the actuator twisted into one of the two maximum positions and this phase position over the kept the entire operation of the internal combustion engine. Because the mid-point, in the camshaft adjuster in depressurized state of the device locked, chosen so is that the internal combustion engine in this phase position of the camshaft has good starting and running properties relative to the crankshaft, result from a maximum phase shift relative to the center position worse starting and running characteristics of the internal combustion engine.

Summary the invention

Of the Invention is therefore the object of these disadvantages to avoid and thus propose a method by which the camshaft can be brought into a phasing relative to the crankshaft in which the hydraulic actuator in a position where it is either locked or in which it is locked while the first rotation of the camshaft automatically at restart the locking position is brought without a piston or wing at an end stop strikes.

Farther should a method be proposed, whereby the adjusting device in unlocked storage position in the locked position is brought.

• – Anfahren und Halten einer definierten Phasenlage φ+X°KW,
• – Ausschalten der Zündung,
• – Einstellen der zweiten oder vierten Steuerstellung (130, 132), um die Phasenlage φ+X°KW zu halten, bis die Drehzahlsensorik die Drehzahl n=0 meldet,
• – Detektieren der Drehzahl n über eine Drehzahlsensorik,
• – Halten der eingenommenen Steuerstellung (130, 132) für eine vorbestimmte Zeitspanne,
• – nach Ablauf der Zeitspanne Deaktivieren der Stelleinheit (112).

In a first method according to the preamble of claim 1, the object is achieved in that the following method steps are carried out in the order listed:

• - starting and holding a defined phase position φ + X ° KW,
• - switching off the ignition,
• - setting the second or fourth control position ( 130 . 132 ) to maintain the phasing φ + X ° CA until the speed sensor detects the speed n = 0,
• Detecting the rotational speed n via a rotational speed sensor system,
• - holding the assumed control position ( 130 . 132 ) for a predetermined period of time,
• - after expiry of the period of time deactivating the actuator ( 112 ).

• – In einem zweiten Verfahren nach dem Oberbegriff des Anspruchs 2 wird die Aufgabe erfindungsgemäß dadurch gelöst, dass folgende Verfahrensschrit te in der aufgeführten Reihenfolge während des Stoppvorgangs durchgeführt werden:
• – Anfahren und Halten einer definierten Phasenlage φ+X°KW,
• – Ausschalten der Zündung,
• – Einstellen der zweiten oder vierten Steuerstellung (130, 132), um die Phasenlage φ+X°KW zu halten, bis die Drehzahlsensorik die Drehzahl n=0 meldet,
• – Detektieren der Drehzahl n über eine Drehzahlsensorik,
• – Halten der eingenommenen Steuerstellung (130, 132) für eine vorbestimmte Zeitspanne,
• – nach Ablauf der Zeitspanne Deaktivieren der Stelleinheit (112). und dass dass folgende Verfahrensschritte in der aufgeführten Reihenfolge während des Startvorgangs durchgeführt werden:
• – Einstellen der ersten Steuerstellung
• – Detektion der Drehzahl n der Kurbelwelle oder der Nockenwelle,
• – ist die Drehzahl n>0: Detektion des Druckmitteldrucks p,
• – ist der Druckmitteldruck p größer als ein vorbestimmter Wert: Einstellen von Steuerstellungen nach dem in der Steuereinheit abgelegtem Kennfeld,

By this method, the adjusting device is brought into a phase position during the stopping process, which deviates from the center locking position by an amount X ° crankshaft (KW). The sign of X depends on the adjustment direction of the adjusting device, if this is not sufficiently filled with pressure medium. For example, if the device is equipped with no compensating spring or compensating spring, which has a low torque on the system rotor stator, the torque is smaller than the drag torque of the rotating camshaft, this phase position is relative to the center locking position in the early direction. In the event that the compensation spring torque is greater and opposite to the camshaft drag torque, this phase position is late relative to the center locking position. through the process steps. After issuing the ignition, that control position is to be assumed which prevents the actuator from moving into the middle position until a rotational speed sensor system signals the rotational speed n = 0. Subsequently, the assumed control position is held for a defined period of time. This is necessary because the speed sensor system in the last revolution of the camshaft / crankshaft already reports the rotational speed n = 0 and due to the alternating torques the actuator can be moved via the center position in the undesired position. By this holding time also relaxation effects of the internal combustion engine are intercepted, for example, relax piston or the like, which also the wrong Position can be taken.

• - In a second method according to the preamble of claim 2, the object is achieved in that the following Verfahrensschrit te be performed in the order listed during the stop process:
• - starting and holding a defined phase position φ + X ° KW,
• - switching off the ignition,
• - setting the second or fourth control position ( 130 . 132 ) to maintain the phasing φ + X ° CA until the speed sensor detects the speed n = 0,
• Detecting the rotational speed n via a rotational speed sensor system,
• - holding the assumed control position ( 130 . 132 ) for a predetermined period of time,
• - after expiry of the period of time deactivating the actuator ( 112 ). and that the following process steps are performed in the order listed during the startup process:
• - Setting the first control position
• Detection of the rotational speed n of the crankshaft or the camshaft,
• Is the rotational speed n> 0: detection of the fluid pressure p,
• The pressure medium pressure p is greater than a predetermined value: setting of control positions according to the map stored in the control unit,

Thereby is guaranteed that the lock is achieved when unlocked, and the Lock can be canceled only when the fluid pressure has reached a certain value and thus a sufficient pressure medium supply ensured the device is. This prevents a striking of a piston or wing, which is the case with an unlocked, not enough with Pressure medium supplied device would be.

• – Einstellen der ersten Steuerstellung
• – Detektion der Drehzahl n der Kurbelwelle oder der Nockenwelle,
• – ist die Drehzahl n>0: Detektion des Druckmitteldrucks p,
• – ist der Druckmitteldruck p größer als ein vorbestimmter Wert: Einstellen von Steuerstellungen nach dem in der Steuereinheit abgelegtem Kennfeld.

In a third method according to the preamble of claim 3, the object is achieved in that the following method steps are performed in the order listed:

• - Setting the first control position
• Detection of the rotational speed n of the crankshaft or the camshaft,
• Is the rotational speed n> 0: detection of the fluid pressure p,
• - Is the pressure medium pressure p greater than a predetermined value: Setting of control positions according to the filed in the control unit map.

Short description the drawings

Further Features of the invention will become apparent from the following description and from the drawings, in the embodiments of the invention are shown simplified. Show it:

1 a longitudinal section through a hydraulic actuator,

2 a cross section through a hydraulic adjusting device according to 1 .

3 a flowchart for a method for starting an internal combustion engine with a device according to the invention for changing the timing of gas exchange valves,

4 a schematic representation of a device according to the invention for changing the timing of gas exchange valves of an internal combustion engine,

5a a longitudinal section through a control valve of a device according to the invention for changing the timing of gas exchange valves of an internal combustion engine in a first control position,

5b a longitudinal section through the control valve 5a in a second control position,

5c a longitudinal section through the control valve 5a in a third control position,

5d a longitudinal section through the control valve 5a in a fourth control position,

6 in a diagram, the volume flow from the inlet port to the pressure chambers in dependence on the position of the control piston relative to the valve housing,

7 a flowchart for a method for the controlled shutdown of an internal combustion engine with a device according to the invention for changing the timing of gas exchange valves and

8th a schematic representation of a device for changing the timing of gas exchange valves of an internal combustion engine from the prior art.

Full Description of the drawing

The 1 and 2 show a hydraulic adjusting device 1a a device 1 for changing the timing of gas exchange valves of an internal combustion engine. The adjustment tung 1a consists essentially of a stator 2 and a concentrically arranged rotor 3 , A drive wheel 4 is non-rotatable with the stator 2 connected and formed in the illustrated embodiment as a sprocket. Also conceivable are embodiments of the drive wheel 4 as a belt or gear. The stator 2 is rotatable on the rotor 3 mounted, wherein on the inner circumferential surface of the stator 2 in the illustrated embodiment, five circumferentially spaced recesses 5 are provided. The recesses 5 be in the radial direction of the stator 2 and the rotor 3 , in the circumferential direction of two side walls 6 of the stator 2 and in the axial direction through first and second side covers 7 . 8th limited. Each of the recesses 5 is sealed pressure-tight in this way. The first and the second side cover 7 . 8th are with the stator 2 by means of connecting elements 9 , For example, screws connected.

On the outer circumferential surface of the rotor 3 are axially extending vane grooves 10 formed, with in each wing groove 10 a radially extending wing 11 is arranged. In every recess 5 a wing extends 11 , where the wings 11 in the radial direction on the stator 2 and in the axial direction on the side covers 7 . 8th issue. Every wing 11 divided a recess 5 in two pressure chambers working against each other 12 . 13 , To a pressure-tight concern of the wings 11 at the stator 2 to ensure there are between the groove reasons 14 the wing grooves 10 and the wings 11 Leaf spring elements 15 attached to the wing 11 act in the radial direction with a force.

By means of first and second pressure medium lines 16 . 17 can the first and second pressure chambers 12 . 13 be connected via an unillustrated control valve with a likewise not shown pressure medium pump or a tank, also not shown. As a result, an actuator is formed which causes a relative rotation of the stator 2 opposite the rotor 3 allows. It is envisaged that either all first pressure chambers 12 with the pressure medium pump and all second pressure chambers 13 connected to the tank or the exactly opposite configuration. Be the first pressure chambers 12 with the pressure medium pump and the second pressure chambers 13 Connected to the tank, the first pressure chambers expand 12 at the expense of the second pressure chambers 13 out. This results in a displacement of the wings 11 in the circumferential direction, in the by the first arrow 21 illustrated direction. By moving the wings 11 becomes the rotor 3 relative to the stator 2 twisted.

The stator 2 is in the illustrated embodiment by means of one on its drive wheel 4 attacking, not shown chain drive driven by the crankshaft. Equally conceivable is the drive of the stator 2 by means of a belt or gear drive. The rotor 3 is positively, positively or materially, for example by means of press fit or by a screw connection by means of a central screw, connected to a camshaft, not shown. From the relative rotation of the rotor 3 relative to the stator 2 , as a result of the supply and discharge of pressure medium to and from the pressure chambers 12 . 13 , results in a phase shift between the camshaft and crankshaft. By targeted introduction and discharge of pressure medium in the pressure chambers 12 . 13 Thus, the timing of the gas exchange valves of the internal combustion engine can be selectively varied.

The pressure medium lines 16 . 17 are executed in the illustrated embodiment as a substantially radially arranged bores extending from a central bore 22 of the rotor 3 extend to the outer lateral surface. Inside the central hole 22 can be arranged a central valve, not shown, via which the pressure chambers 12 . 13 can be selectively connected to the pressure medium pump or the tank. Another possibility is inside the central hole 22 to arrange a pressure medium distributor, the pressure medium lines 16 . 17 connects via pressure medium channels and annular grooves with the terminals of an externally mounted control valve.

The substantially radially extending side walls 6 the recesses 5 are with formations 23 provided in the circumferential direction in the recesses 5 extend. The formations 23 serve as a stop for the wings 11 and ensure that the pressure chambers 12 . 13 can be supplied with pressure medium, even if the rotor 3 one of its two extreme positions relative to the stator 2 occupies, in which the wings 11 on one of the side walls 6 issue.

With insufficient pressure medium supply of the device 1 For example, during the starting phase of the internal combustion engine, the rotor 3 uncontrolled relative to the stator due to the alternating and drag torque exerted by the camshaft 2 emotional. In a first phase, the drag torques of the camshaft urge the rotor relative to the stator in a circumferential direction which is opposite to the direction of rotation of the stator until it reaches the sidewalls 6 attacks. In the following, the alternating moments cause the camshaft on the rotor 3 exerts to a swinging back and forth of the rotor 3 and with it the wing 11 in the recesses 5 until at least one of the pressure chambers 12 . 13 completely filled with pressure medium. This leads to higher wear and noise developments in the device 1 , To prevent this are in the device 1 two locks development elements 24 intended. Each locking element 24 consists of a cup-shaped piston 26 which is in an axial bore 25 of the rotor 3 is arranged. The piston 26 is by a spring 27 acted upon in the axial direction with a force. The feather 27 is supported in the axial direction on one side of a venting element 28 from and is facing away from the axial end within the pot-shaped executed piston 26 arranged.

In the first page cover 7 is per locking element 24 a backdrop 29 formed such that the rotor 3 relative to the stator 2 can be locked in a position corresponding to the position during the start of the internal combustion engine. In this position, the pistons 26 at insufficient pressure medium supply of the device 1 by means of the springs 27 into the scenes 29 crowded. Furthermore, means are provided for the pistons 26 with sufficient supply of the device 1 with pressure medium in the axial bores 25 push back and thus unlock the lock. This is usually accomplished with pressure medium, which via not shown pressure medium lines in a recesses 30 is passed, which at the cover-side front end of the piston 26 is trained. Corresponds to the phase position φ, which corresponds to the starting position of the internal combustion engine, a center position of the wings 11 between the respective side walls 6 , so can a lock of the hydraulic actuator 1a in this position by the use of two locking elements 24 and customized backdrops 29 be accomplished.

To leakage oil from the spring chamber of the axial bore 25 to be able to derive the venting element 28 provided with axially extending grooves, along which the pressure medium to a bore in the second side cover 8th can be directed.

8th shows a device 101 for changing the timing of gas exchange valves of an internal combustion engine from the prior art. This consists of a hydraulic actuator 102 and a control valve 103 ,

The adjusting device 102 consists of a pressure room 104 by a sliding element 105 in two opposing pressure chambers 106 . 107 is divided. The movable element 105 is rotatably connected to the camshaft or the crankshaft, while the other component rotatably connected to the pressure chamber 104 connected is. The movable element 105 is motion-proof with two scenes 108 . 109 connected. Furthermore, with 110 respectively. 111 each denotes a locking pin, which is stationary to the pressure chamber 104 are attached. Every scenery 108 . 109 is ever a Verrieglungspin 110 . 111 assigned. Alternatively, the locking pins 110 . 111 with the element 105 move along and the scenes 108 . 109 in a to the pressure room 104 be formed stationary component.

The control valve 103 consists of an actuator 112 , a first spring element 113 and a valve body 114 , The actuator 112 For example, in the form of an electrical or hydraulic actuator 112 be educated. In the following, without limitation of generality, an electric actuator 112 be assumed, which is designed as an electromagnet. At the valve body 114 is a first working port A, a second working port B, an inlet port P and a drain port T formed. The first working port A is connected via a first pressure medium line 115 with the first pressure chamber 106 and the second working port B via a second pressure medium line 116 with the second pressure chamber 107 in connection. Furthermore, the drain port T is connected to a pressure medium reservoir 117 in connection. About a pressure medium pump 118 a filter 119 and a return check valve 120 the supply port P is pressurized with pressure medium. Via a third pressure medium line 121 is the first backdrop 108 in conjunction with the first pressure medium line 115 , Likewise, the second backdrop 109 via a fourth pressure medium line 122 in conjunction with the second pressure medium line 116 , The first and second scenery 108 . 109 are each formed as a groove, wherein the dimension in the direction of movement of the movable member 105 is greater than that of the respective Verrieglungspins 110 . 111 , Both locking pins 110 . 111 engage in the illustrated center position of the movable element 105 into the respective backdrop 108 . 109 and are in the direction of displacement of the movable element 105 arranged at one end of the respective groove.

By means of the actuator 112 the valve can against the spring force of the first spring element 113 in a second, a third and a fourth control position 130 . 131 . 132 to be brought. Is the valve in the second control position 130 which at low to no energization of the actuator 112 the case is, the second working port B is exclusively connected to the inlet port P and the first working port A exclusively to the drain port T.

Is the valve in the third control position 131 What with low to medium energization of the actuator 112 is the case, both working ports A, B are connected neither to the inlet port P nor to the drain port T. Alternatively it can be provided that both working ports A, B are connected exclusively to the inlet port P to compensate for leakage losses.

If the valve is in the fourth control position 132 , what with medium to maximum energization of the actuator 112 the case is, the first working port A is exclusively connected to the inlet port P and the second working port B exclusively to the drain port T.

In controlled operation of the internal combustion engine, the control valve 103 in the second control position 130 brought about an adjustment of the movable element 105 Towards late, marked by the second arrow 126 , to reach. Pressure medium is from the inlet port P via the second working port B and the second pressure medium line 116 to the second pressure chamber 107 directed. At the same time via the fourth pressure medium line 122 Pressure medium in the second backdrop 109 directed. This will be the second locking pin 111 against the force of a second spring 129 from the second backdrop 109 crowded. At the same time, the first pressure chamber 106 over the first pressure medium line 115 and the drain port T with the pressure medium reservoir 117 connected. By the flow of pressure fluid from the first pressure chamber 106 and the inlet of pressure medium to the second pressure chamber 107 becomes the movable element 105 moved towards late. At the same time, the first and the second scenery 108 . 109 also moved towards late. In this case, the first locking pin moves 110 within the first backdrop 108 while the second locking pin 111 outside the second backdrop 109 located.

To a phase angle φ of the hydraulic actuator 102 to hold the control valve 103 in the third control position 131 brought. Both working ports A, B are connected neither to the supply P nor to the drain port T. There is no inflow or outflow of pressure medium to or from the pressure chambers 106 . 107 instead and the phase angle φ is kept constant. To an adjustment of the movable element 105 towards early, characterized by the third arrow 128 to reach the control valve 103 in the fourth control position 132 brought. Pressure medium is from the inlet port P via the first working port A and the first pressure medium line 115 to the first pressure chamber 106 directed. At the same time, the third pressure medium line is used 121 Pressure medium in the first backdrop 108 directed. This will be the first locking pin 110 against the force of a first spring 127 from the first backdrop 108 crowded. At the same time, the second pressure chamber 107 via the second pressure medium line 116 and the drain port T with the pressure medium reservoir 117 connected. By the flow of pressure medium from the second pressure chamber 107 and the inlet of pressure medium to the first pressure chamber 106 becomes the movable element 105 moved towards early. At the same time, the first and the second scenery 108 . 109 also moved towards early. In this case, the second locking pin moves 111 within the second backdrop 109 while the first locking pin 110 outside the first backdrop 108 located.

Becomes the movable element 105 from a position of the in 8th shown center position differs over the center position adjusted, so locks the locking pin 110 . 111 , which is not acted upon by pressure medium in the respective backdrop 108 . 109 one. At the same time, the other locking pin 110 . 111 pressurized so that it is outside the backdrop 108 . 109 located. The movement is solely by the latched locking pin 110 . 111 limited.

Is the hydraulic actuator located 102 in the in 8th illustrated middle position and is the device 101 not supplied with sufficient pressure medium, which is the case for example when starting the internal combustion engine, both locking pins are in 110 . 111 in the respective scenery 108 . 109 engaged. Here are the locking pins 110 . 111 arranged in such a way and the scenes 108 . 109 executed such that the locking pins 110 . 111 at the ends of the scenes 108 . 109 located furthest apart. This is the movable element 105 relative to the pressure chamber 104 fixed. Alternatively, the locking pins can 110 . 111 at the ends of the scenes 108 . 109 are closest to each other. In this alternative embodiment would have the first backdrop 108 from the second pressure medium line 116 and the second backdrop 109 from the first pressure medium line 115 be acted upon with pressure medium. Also conceivable is an admission of the scenes 108 . 109 over the respective pressure chamber 106 . 107 , for example by means of a worm groove.

When stopping the internal combustion engine, there is the possibility that the displaceable element 105 is positioned in a late position relative to the center position. When restarting the device is 101 not yet sufficiently filled with pressure medium. Due to the drag torque of the camshaft is the element 105 in the direction of the late attack 133 driven and strikes there. This leads to increased wear of the components and unpleasant noise.

If the actuator falls 112 of the control valve 103 off, the power supply is interrupted, for example, by a defect of the electromagnet or the power connections, then the control valve 103 in the second control position 130 added. This causes the second locking pin 111 is unlocked and the camshaft is moved relative to the crankshaft in the late direction. As a result, the starting and running characteristics of the Internal combustion engine operating in the 8th center position are optimal, deteriorate.

In the schematically illustrated hydraulic actuator 102 For example, it may be an axial piston adjuster or a rotary piston adjuster. In the following, only the embodiment of a rotary piston adjuster is to be treated without limiting the generality. The pressure room 104 corresponds to the recesses 5 out 1 , The movable element 105 the wings 11 , The locking pins 110 . 111 can in the embodiment according to 1 either in a side cover of the rotary piston adjuster or in the rotor of the rotary piston adjuster within a bore, preferably a blind hole. The respective scenes 108 . 109 are formed in the respective other component.

In 4 is a device according to the invention 101 schematic, analog 8th represented. This is mostly with the in 8th shown identical, which is why the same reference numerals have been used for the same components. The difference of the device according to the invention 101 is that the control valve 103 additionally a first control position 140 having. The first control position 140 is activated when the actuator 112 assumes a state that corresponds to a low to no energization. The first spring element 113 in this case ensures that the first control position 140 is reached. In this position, neither the first nor the second working port A, B is connected to the inlet port P. Depending on the configuration of the hydraulic actuator 102 can now either the first or the second working port A, B are connected to the drain port T, while the other working port A, B does not communicate with the drain port T. Also conceivable is an embodiment in the in the first control position 140 the first and the second working port A, B communicates neither with the inflow port P nor with the outflow port T or both working ports A, B are exclusively connected to the outflow port T.

In addition to the first control position 140 has the control valve 103 likewise the in 8th illustrated second, third and fourth control positions 103 . 131 . 132 on, with the second control position 130 at a low to medium current, the third control position 131 at a medium to high current and the fourth control position 132 at a high to maximum current, the actuator 112 is taken.

In case of a defect of the actuator 112 or a fault in their power supply enters the control valve 103 automatically in the first control position 140 , wherein the switching valve 103 this position until the repair of the actuator 112 or their power supply stops. After a restart of the internal combustion engine is due to the insufficient pressure medium supply of the hydraulic actuator 102 the movable element 105 regardless of its position on the switching off of the internal combustion engine due to the towing and alternating moments moved to the middle position. There can both locking pins 110 . 111 into the respective backdrop 108 . 109 lock in, reducing the position of the movable element 105 in the pressure room 104 is fixed. Due to the configuration of the first control position 140 is no pressure fluid to the pressure chambers during operation of the internal combustion engine 106 . 107 and thus to the scenes 108 . 109 guided. This has the consequence that the movable element 105 relative to the pressure chamber 104 is held stationary and thus the phase angle φ between the camshaft and crankshaft is kept constant in the emergency position, in which the internal combustion engine has good starting and running properties.

The 5a to 5d show an example of a valve body 114 a control valve 103 a device according to the invention 101 , The valve body 114 consists of a valve housing 141 and a control piston 142 , The valve housing 141 is designed substantially hollow cylindrical, wherein in the outer circumferential surface thereof, three axially spaced annular grooves 143 . 144 . 145 are formed. Each of the ring grooves 143 to 145 represents a connection of the valve, wherein the axially outer annular grooves 143 . 145 the working connections A, B form and the middle annular groove 144 the inlet port P. A drain port T is through an opening in an end face of the valve housing 141 executed. Each of the ring grooves 143 to 145 is above first radial openings 146 with the inside of the valve body 141 in connection. Inside the valve housing 141 is a substantially hollow cylindrical executed control piston 142 arranged axially displaceable. The control piston 142 is at a front side of a second spring element 147 and on the opposite end face of a push rod 148 the actuator 112 acted upon with a force. By energizing the actuator 112 can the spool 142 against the force of the second spring element 147 in any position between a first and a second end stop 149 . 150 be moved.

The control piston 142 is with a first and a second ring bridge 151 . 152 Mistake. The outer diameter of the ring lands 151 . 152 are the inner diameter of the valve body 141 customized. Furthermore, in the control piston 142 between its frontal end, on which the push rod 148 attacks, and the second ring land 152 second radial openings 146a formed, whereby the interior of the control piston 142 with the interior of the valve housing 141 communicates. The first and the second ring bridge 151 . 152 are formed and on the outer circumferential surface of the control piston 142 arranged that control edges 153 to 156 depending on the position of the control piston 142 relative to the valve housing 141 a connection between the inlet port P and the working ports A, B releases or blocks and a connection between the working ports A, B and the drain port T releases or blocks. The outer diameter of the control piston 142 is in the areas between the pushrod 148 and the second ring land 152 and between the first ring land 151 and the second ring land 152 made smaller than the inner diameter of the valve housing 141 , As a result, between the first and the second ring land 151 . 152 a fourth annular groove 157 educated. Within the fourth ring groove 157 is a third Ringsteg 158 educated. The outer diameter of the third ring land 158 is the inner diameter of the valve body 141 customized. Furthermore, the third ring land 158 positioned so that it is in the first control position 140 of the control valve 103 the connection between the inlet port P and the second working port B locks.

5a shows the first control position 140 of the control valve 103 in which the control piston 142 from the actuator 112 over the pushrod 148 with a force between a minimum force and a small F _{1 is} applied. The push rod-side end face of the control piston 142 located in an area between the first end stop 149 (Displacement = 0 mm) and a displacement s ₁ . The connection between the inlet port P and the second working port B is through the third ring land 158 and the connection between the inlet port P and the first working port A through the first ring land 151 blocked. Furthermore, the connection between the second working port B and the drain port T by means of the second ring land 152 locked, while pressure fluid from the first working port A to the drain port T can flow. Since the pressure medium flow to both locking pins 110 . 111 and to both pressure chambers 106 . 107 is blocked in the first control position 140 no active adjustment take place. By connecting the first pressure chamber 106 with the reservoir 11 this is emptied. Depending on the position of the hydraulic actuator 102 becomes the movable element 105 immediately, or after a certain time, which is needed around the second pressure chamber 107 due to leakage to empty, driven due to drag or alternating torques of the camshaft in the center position and there permanently locked.

This control position corresponds to a configuration of the control valve 103 in the actuator 112 is energized and therefore the control piston 142 by means of the second spring element 147 at the first end stop 149 is shifted, so the displacement is zero. In this position is the valve when the actuator 112 defective or their power supply is interrupted.

5b shows the second control position 130 of the control valve 103 in which the control piston 142 from the actuator 112 over the pushrod 148 with a force between a small force F, and an average force F ₂ , F ₂ > F ₁ . This will be the spool 142 a distance S ₁ to S ₂ from the push rod side first end stop 149 shifted, where S ₂ > S ₁ . The first ring bridge 151 furthermore blocks the connection between the first working port A and the inflow port P, while further pressure fluid can flow from the first working port to the discharge port T. Furthermore blocked the second ring land 152 the connection between the second working port B and the drain port T, while both the second and the third ring land 152 . 158 a connection between the inlet port P and the second working port B releases. In this position is via the second working port B, the second and fourth pressure medium line 116 . 122 the second pressure chamber 107 and the second backdrop 109 Pressure medium supplied, whereby the second locking pin 111 is unlocked and the hydraulic actuator 102 Directed late. At the same time, pressure fluid flows out of the first pressure chamber 106 over the first pressure medium line 115 to the first working port A and from there to the drain port T.

5c shows the third control position 131 of the control valve 103 in which the control piston 142 from the actuator 112 over the pushrod 148 with a force between a mean F ₂ and a large force F _{3 is} applied, wherein F ₃ > F ₂ . This will be the spool 142 a distance S ₂ to S ₃ from the push rod side first end stop 149 shifted, where S ₃ > S ₂ . In this position of the switching valve block the first and the second ring land 151 . 152 the connections between the working ports A, B and the inlet port P and the connections between the working ports A, B and the drain port T. In this position of the control valve 103 will neither pressure medium to the pressure chambers 106 . 107 fed, nor can pressure medium from the pressure chambers 106 . 107 flow away. This control position thus corresponds to a holding position in which the phase angle φ between the camshaft and the crankshaft is kept constant.

5d shows the fourth control position 132 of the control valve 103 in which the control piston 142 from the actuator 112 over the pushrod 148 with a force between a large force F ₃ and a maximum force F _{4 is} applied, wherein F ₄ > F ₃ . This will be the spool 142 a distance S ₃ to S ₄ from the push rod side first end stop 149 shifted, where S ₄ > S ₃ . In this configuration, the first ring land is blocked 151 a connection between the first working port A and the drain port T, while the connection between the inlet port P and the first working port A both from the first annular web 151 , as well as from the third ring walkway 158 is released. Furthermore, from the second ring land 152 the connection between the inlet port P and the second working port B blocks while pressure means via the second working port B and the second radial ports 146a into the interior of the control piston 142 and from there to the drain port T can get. In this position of the control valve 103 becomes pressure medium from the second pressure chamber 107 via the second pressure medium line 116 to the second working port B and from there to the drain port T passed. At the same time, the first pressure medium line is via the first working port A. 115 and the third pressure medium line 121 Pressure medium to the first pressure chamber 106 and the first backdrop 108 directed. This will be the first locking pin 110 unlocked and the hydraulic actuator 102 adjusted to early.

By using the described 4/4-way valve, as a control valve 103 the device according to the invention 101 , no additional modules, such as additional control valves are needed to a device 101 with center-position interlock that launches automatically in a locked center position, hitting the element 105 (Wing at Vane adjusters) stops at a stop. Neither the space, nor the manufacturing or assembly costs are increased compared to the embodiment described in the prior art. At the same time the device 101 in case of failure of the actuator 112 brought into the center position and there to repair the actuator 112 locked.

6 sets the volume flow from the inlet connection T to the pressure chambers 106 . 107 depending on the duty cycle of the actuator 112 dar. The actuator 112 can be applied to a voltage, with either zero volts or a maximum value is applied. The duty cycle indicates the proportion of time in which the maximum value of the voltage at the actuator 112 is applied. The higher the duty cycle, the higher the force of the actuator 112 over the pushrod 148 on the control piston 142 is exercised. Thus, the duty cycle is a measure of the displacement of the control piston 142 inside the valve body 141 relative to the first end stop 149 ,

In a first range in which the duty cycle is between zero and a first value TV1 takes the control valve 103 the first control position 140 one. In this control position 140 are the connections between the inlet port P and the working ports A, B blocked, the flow is apart from leakage flows 0th

If the duty cycle lies between a first value TV1 and a second value TV2, then the control valve is located 103 in the second control position 130 , Pressure medium can pass from the inlet connection P to the second working connection B, while the connection between the inlet connection P and the first working connection A is blocked. The volumetric flow increases steadily as the duty cycle increases from a first value TV1 to a third value TV3, while when increasing further up to the second value TV2 it steadily decreases and finally at the value TV2 it approaches zero. Advantageously, for the second control position 130 only the area between TV3 and TV2 used.

In a third range between the value TV2 and a value TV4, duty cycles which lie in this range are referred to below as a hold duty ratio, the duty cycle of the volume flow is almost zero. This area corresponds to the third control position 131 of the control valve 103 in which both working connections A, B are not in connection with the inlet connection P.

If the value of the duty cycle is increased further from the value TV4 to 100%, then the volume flow from the feed port P to the pressure chamber increases 106 . 107 initially steadily too. The volume flow can rise steadily up to a duty factor of 100%, or, for design reasons, can go through a maximum. This area corresponds to the fourth control position 132 of the control valve 103 in that pressure medium is conducted from the inlet connection P to the first working connection A, while the connection between the inlet connection P and the second working connection B is blocked.

Besides the advantage that if the actuator fails 112 at a restart of the internal combustion engine, the hydraulic actuator 102 is locked in a center position and this lock is held, allows the device according to the invention 101 with intact actuator 112 a lock of the hydraulic actuator 102 in the center position when switching off the internal combustion engine or positioning the hydraulic actuator 102 such that when restarting the internal combustion engine, the hydraulic actuator 102 placed in the center position and locked there. This has the advantage that during the Starting process in which the device 101 not yet sufficiently filled with pressure medium, the hydraulic actuator 102 securely locked in the center position, creating a striking of the sliding element 105 on a side wall of the pressure chamber 104 is avoided, whereby increased wear and noise is avoided.

To operate the internal combustion engine, the different duty cycles, in particular TV1 to TV3 and the hold duty cycle TV _{hold must be known to} the engine control unit. The hold duty ratio is determined by the engine control unit as standard and stored in a memory unit. For the determination of TV1, TV2 and TV3 two possibilities are conceivable.

About the structural design and the consequent valve characteristics TV1, TV2 and TV3 can be determined in direct dependence on the holding load ratio TV _hold . The difference angles Y ₁ , Y ₂ and Y ₃ are stored permanently in a memory unit. The engine control unit determines the hold duty ratio TV _hold in an early phase of the operation of the internal combustion engine. For TV1, TV2 and TV3 then: TV1 = TV holding - Y1, TV2 = TV holding - Y2, TV3 = TV holding - Y3.

A second way is to have TV1 and TV2, optionally after each restart, determined by the engine control unit and store in the map. To determine TV1 and TV3, the camshaft angle signals and crankshaft angle signals can be used. Above all, the relative phase angle of the two waves and the temporal change of the phase position can be used for this purpose. For example, the following method can be used. A ramp of duty cycle of 0% is increased. The value TV1 is reached when an adjustment operation starts (at this point, one of the pressure chambers becomes 106 . 107 and a locking pin 110 . 111 subjected to pressure medium and the hydraulic actuator adjusted, which can be detected via camshaft angle sensors and crankshaft angle sensors). The value TV3 is reached when a maximum adjustment speed is exceeded. TV2 is reached when the phase position is kept constant. The determined values are then stored in a memory.

7 shows a flowchart of a method for controlling the device according to the invention 101 during a stop operation of the internal combustion engine, by which the hydraulic actuator 102 is brought into a position in which it is either locked after the stop of the internal combustion engine or in a position from which it is moved directly after the restart of the internal combustion engine in the center position and locked there.

When initiating the stopping process of the internal combustion engine, the rotational speed n> zero. The phase angle φ between the camshaft and the crankshaft is determined by means of the control valve 103 brought into a Abstellphasenlage, which differs by a defined amount X of the locking phase position φ _center . From the Abstellphasenlage is for a device 101 , which is executed without compensation spring, relative to the locking phase position φ _center shifted towards early. The same applies to a device 101 , which is equipped with a compensation spring, but whose torque is smaller than the drag torque of the camshaft. For a device 101 with a compensation spring which exerts a torque which is greater than the drag torque of the camshaft, the parking phase is shifted relative to the locking phase position φ _middle in the late direction. If the predetermined Abstellphasenlage is reached, the ignition is turned off and the value of the duty cycle is set such that this phase φ is held securely. In the case of setting a postponed Abstellphasenlage the duty cycle is thus between TV2 and 100%, in the case of a Abstellphasenlage which is relative to the Verrieglungsphasenlage φ _center adjusted late between TV4 and TV3. This duty cycle is maintained until the speed sensors report zero speed. Thereafter, the set duty cycle for a certain period of time Y is held before finally the actuator 112 is kept de-energized. The holding time of Y prevents during the last revolution of the internal combustion engine, during which the rotational speed sensor already delivers the rotational speed n = 0, due to pressure fluctuations caused by the alternating torques, the locking pins 110 . 111 unlocked and the movable element 105 is pushed over the center position in the wrong position.

The hydraulic actuator 102 is now either, due to the last revolution of the crankshaft, in the locked state or in a position in which it is automatically and immediately driven into the locked position either by the drag torque of the camshaft or the torque of the compensation spring when starting the internal combustion engine.

3 shows a flowchart of a method for starting an internal combustion engine with a device according to the invention 101 , which ensures that an already existing or during the first revolution of the crankshaft manufactured locking of the movable element 105 is held until the oil pressure within the internal combustion engine has risen to a value for the safe operation of the device 101 is needed. At the beginning of the starting process, the speed n and the duty cycle is zero. As long as the speed sensor reports a speed n = zero, the duty cycle is kept between zero% and the value TV1. If the speed sensor reports a speed> zero, the value of an oil pressure sensor is read out. As long as the value of the oil pressure p is smaller than a certain minimum value p _min , which is necessary for the device according to the invention 101 To operate safely, the value of the duty cycle is kept between zero% and the value TV1. If the oil pressure p exceeds the predetermined pressure, the device goes 101 in the regulated operation over and the duty cycle is adjusted depending on load condition of the machine between TV3 and 100%.

The aforementioned embodiments are only exemplary. Of course, the working connections A, B are interchangeable. Also included in the scope are devices 101 with center position locking of the hydraulic actuator 102 wherein only one locking pin can engage in a backdrop or a stepped backdrop. Also devices with any locking phasing with one or more locking pins. When considering the volume flows and the connections between different connections of the switching valve, pressure losses due to leakage were neglected.

1

contraption

1a

hydraulic Stellvorrich

tung

2

stator

3

rotor

4

drive wheel

5

recesses

6

Side wall

7

first side cover

8th

second side cover

9

connecting element

10

vane

11

wing

12

first pressure chamber

13

second pressure chamber

14

groove base

15

Leaf spring element

16

first Pressure medium line

17

second Pressure medium line

21

first arrow

22

central bore

23

formations

24

locking element

25

axial bore

26

piston

27

feather

28

A vent

29

scenery

30

recess

101

contraption

102

hydraulic Stellvorrich

tung

103

control valve

104

pressure chamber

105

element

106

first pressure chamber

107

second pressure chamber

108

first scenery

109

second scenery

110

first locking pin

111

second locking pin

112

actuator

113

first spring element

114

valve body

115

first Pressure medium line

116

second Pressure medium line

117

Pressure fluid reservoir

118

Hydraulic pump

119

filter

120

check valve

121

third Pressure medium line

122

fourth Pressure medium line

126

second arrow

127

first feather

128

third arrow

129

second feather

130

second control position

131

third control position

132

fourth control position

133

late stop

140

first control position

141

valve housing

142

spool

143

ring groove

144

ring groove

145

ring groove

146

first radial openings

146a

second radial openings

147

second spring element

148

pushrod

149

first end stop

150

second end stop

151

first ring land

152

second ring land

153

first control edge

154

second control edge

155

third control edge

156

fourth control edge

157

fourth ring groove

158

third ring land

P

inflow connection

T

drain connection

A

first working port

B

second working port

φ

phasing

φ _middle

Locking phase

X

amount

Y ₁

difference angle

Y ₂

difference angle

Y ₃

difference angle

TV _hold

holding duty

p _min

oil pressure

Claims (3)

Method for controlling a device ( 101 ) for changing the timing of gas exchange valves of an internal combustion engine during the stopping of the internal combustion engine with - a hydraulic actuator ( 102 ), the two opposing pressure chambers ( 106 . 107 ), - whereby by supply and removal of pressure medium to and from the pressure chambers ( 106 . 107 ) a phase position (φ) of a camshaft relative to a crankshaft held or can be selectively changed, - and with a control valve ( 103 ) with two working ports (A, B), a drain (T) and a supply port (P), wherein the first working port (A) with the first pressure chamber ( 106 ), the second working port (B) with the second pressure chamber ( 107 ) and the drain port (T) communicates with a tank and the inlet port (P) is acted upon with pressure medium, - wherein the control valve ( 103 ) by means of an actuator ( 112 ) in four control positions ( 103 . 131 . 132 . 140 ), wherein - in a first control position ( 140 ) of the control valve ( 103 ), neither the first working connection (A) nor the second working connection (B) communicates with the inflow connection (P), - in a second control position ( 130 ) of the control valve ( 103 ) the first working connection (A) communicates with the outflow connection (T) and the second working connection (B) communicates with the inflow connection (P), - in a third control position ( 131 ) of the control valve ( 103 ) the first and the second working connection (A, B) communicate neither with the outflow connection (T) nor with the inflow connection (P) or the first and the second working connection (A, B) communicate exclusively with the inflow connection (P), a fourth control position ( 132 ) of the control valve ( 103 ) the second working connection (B) communicates with the discharge connection (T) and the first working connection (A) with the supply connection (P), characterized in that the following process steps are carried out in the order listed: - starting and holding a defined phase position φ + X ° KW, - switching off the ignition, - setting the second or fourth control position ( 130 . 132 ) to keep the phase position φ + X ° KW until the speed sensor system reports the speed n = 0, - detecting the speed n via a speed sensor system, - holding the assumed control position ( 130 . 132 ) for a predetermined period of time, - after expiry of the period of time, deactivating the actuating unit ( 112 ). Method for controlling a device ( 101 ) for changing the timing of gas exchange valves of an internal combustion engine during the starting process of the internal combustion engine with - a hydraulic actuator ( 102 ), the two opposing pressure chambers ( 106 . 107 ), - whereby by supply and removal of pressure medium to and from the pressure chambers ( 106 . 107 ) a phase position (φ) of a camshaft relative to a crankshaft held or can be selectively changed, - and with a control valve ( 103 ) with two working ports (A, B), a drain (T) and a supply port (P), wherein the first working port (A) with the first pressure chamber ( 106 ), the second working port (B) with the second pressure chamber ( 107 ) and the drain port (T) communicates with a tank ei and the inlet port (P) is acted upon with pressure medium, - wherein the control valve ( 103 ) by means of an actuator ( 112 ) in four control positions ( 103 . 131 . 132 . 140 ), wherein - in a first control position ( 140 ) of the control valve ( 103 ), neither the first working connection (A) nor the second working connection (B) communicates with the inflow connection (P), - in a second control position ( 130 ) of the control valve ( 103 ) the first working connection (A) communicates with the outflow connection (T) and the second working connection (B) communicates with the inflow connection (P), - in a third control position ( 131 ) of the control valve ( 103 ) the first and the second working connection (A, B) communicate neither with the outflow connection (T) nor with the inflow connection (P) or the first and the second working connection (A, B) communicate exclusively with the inflow connection (P), a fourth control position ( 132 ) of the control valve ( 103 ) the second working port (B) with the drain port (T) and the first working port (A) communicates with the inlet port (P), characterized in that the following steps are performed in the order listed: - Setting the first control position - Detection of the speed n the crankshaft or the camshaft, - is the rotational speed n> 0: detection of the fluid pressure p, - is the fluid pressure p greater than a predetermined value: setting of control positions according to the filed in the control unit map. Method for controlling a device ( 101 ) for changing the timing of gas change-over valves of an internal combustion engine with - a hydraulic actuator ( 102 ), the two opposing pressure chambers ( 106 . 107 ), - whereby by supply and removal of pressure medium to and from the pressure chambers ( 106 . 107 ) a phase position (φ) of a camshaft relative to a crankshaft held or can be selectively changed, - and with a control valve ( 103 ) with two working ports (A, B), a drain (T) and a supply port (P), wherein the first working port (A) with the first pressure chamber ( 106 ), the second working port (B) with the second pressure chamber ( 107 ) and the drain port (T) communicates with a tank and the inlet port (P) is acted upon with pressure medium, - wherein the control valve ( 103 ) by means of an actuator ( 112 ) in four control positions ( 103 . 131 . 132 . 140 ), wherein - in a first control position ( 140 ) of the control valve ( 103 ), neither the first working connection (A) nor the second working connection (B) communicates with the inflow connection (P), - in a second control position ( 130 ) of the control valve ( 103 ) the first working connection (A) communicates with the outflow connection (T) and the second working connection (B) communicates with the inflow connection (P), - in a third control position ( 131 ) of the control valve ( 103 ) the first and the second working connection (A, B) communicate neither with the outflow connection (T) nor with the inflow connection (P) or the first and the second working connection (A, B) communicate exclusively with the inflow connection (P), a fourth control position ( 132 ) of the control valve ( 103 ) the second working port (B) communicates with the discharge port (T) and the first working port (A) with the supply port (P), characterized in that the following process steps are carried out in the order listed during the stop process: - starting and holding a defined Phase angle φ + X ° KW, - switching off the ignition, - setting the second or fourth control position ( 130 . 132 ) to keep the phase position φ + X ° KW until the speed sensor system reports the speed n = 0, - detecting the speed n via a speed sensor system, - holding the assumed control position ( 130 . 132 ) for a predetermined period of time, - after expiry of the period of time, deactivating the actuating unit ( 112 ), and that the following process steps are carried out in the order listed during the starting process: - setting the first control position - detecting the rotational speed n of the crankshaft or the camshaft, - is the rotational speed n> 0: detection of the fluid pressure p, - is the fluid pressure p greater than a predetermined value: setting of control positions according to the map stored in the control unit.