EP1797285A1

EP1797285A1 - Device for modifying the timing of gas exchange valves in an internal combustion engine

Info

Publication number: EP1797285A1
Application number: EP05782451A
Authority: EP
Inventors: Marco Schmitt; Jochen Auchter
Original assignee: Schaeffler KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2004-10-07
Filing date: 2005-09-03
Publication date: 2007-06-20
Anticipated expiration: 2025-09-03
Also published as: DE502005007868D1; CN100529335C; KR20070100231A; JP2008516129A; EP1914395A1; JP4982867B2; EP1797285B1; EP1914395B1; WO2006039966A1; CN101040102A; DE502005008502D1; KR101201609B1; DE102004049123A1

Abstract

The invention relates to a device (101) for modifying the timing of gas exchange valves in an internal combustion engine using a hydraulic regulator (102) and a control valve (103). The inventive device (101) is equipped with a central-position locking mechanism for the hydraulic regulator (102). According to the invention, if a controller (112), which regulates the control valve (103), malfunctions, the hydraulic regulator (102) is locked in the central position until the controller (112) is repaired. In addition, the inventive device (101) permits the internal combustion engine to be started in a locked central position, without a displaceable element (105) of the hydraulic regulator (102) striking a lateral wall of a pressure chamber (104) during said start procedure. The invention also relates to a method for bringing the hydraulic regulator (102) into a locked position and maintaining said position for a new start-up of the internal combustion engine in a locked central position.

Description

Name of the invention

Device for changing the timing of gas exchange valves

Internal combustion engine

description

Field of the invention

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

In internal combustion engines, camshafts are used to actuate the gas exchange valves. Camshafts are mounted in the internal combustion engine in such a way that cams attached to them abut cam followers, for example cup tappets, drag levers or rocking levers. If a camshaft is set in rotation, the cams roll on the cam followers, which in turn actuate the gas exchange valves. As a result of the position and the shape of the cams, both the opening duration and the opening amplitude but also the opening and closing times of the gas exchange valves are defined.

Modern engine concepts go to design the valve train variable. On the one hand, valve lift and valve opening duration should be variable, up to the complete shutdown of individual cylinders. For this purpose, concepts such as switchable cam followers or electrohydraulic or electric valve actuations are provided. Furthermore, it has proven advantageous to be able to influence the opening and closing times of the gas exchange valves during operation of the internal combustion engine. In this case, it is particularly desirable to be able to influence the opening or closing times of the inlet or outlet valves separately in order to set a defined valve overlap, for example. By the attitude the opening and closing times of the gas exchange valves in dependence on the current map range of the engine, for example, the current speed or the current load, the specific fuel consumption can be lowered, the exhaust behavior positively influenced, the engine efficiency, the maximum torque and the maximum power can be increased.

The described variability of the valve timing is achieved by a relative change in the phase angle of the camshaft to the crankshaft. The camshaft is usually via a chain, belt, gear drive or equivalent drive concepts in drive connection with the crankshaft. Between the driven by the crankshaft chain, belt or Zahn¬ wheel drive and the camshaft, a device for changing the Steuerzei¬ th an internal combustion engine, hereinafter also called camshaft adjuster, called attached, the torque from the crankshaft to the cam wave transmits. In this case, this device is designed such that during operation of the internal combustion engine, the phase angle between the crankshaft and camshaft securely held and, if desired, the camshaft can be rotated in a certain angular range relative to the crankshaft.

In internal combustion engines, each with a camshaft for the intake and exhaust valves, these can each be equipped with a camshaft adjuster. As a result, the opening and closing times of the intake and exhaust valves can be shifted relative to one another in terms of time and the valve overlaps can be adjusted in a targeted manner.

The seat of modern camshaft adjusters is usually located on the drive end of the camshaft. However, the camshaft adjuster can also be arranged on an intermediate shaft, a non-rotating component or the crankshaft. It consists of a driven by the crankshaft, a fixed phase relation to this holding drive wheel, a drive connection with the drive cam with the camshaft output part and a torque from the drive wheel to the driven part transmitting Verstellmechanis- In the case of a camshaft adjuster not arranged on the crankshaft, the drive wheel can be designed as a chain, belt or toothed wheel and is driven by the crankshaft by means of a chain drive, a belt drive or a toothed wheel drive. The adjustment mechanism can be operated electrically, hydraulically or pneumatically.

Two preferred embodiments of hydraulically adjustable camshaft adjusters are the so-called axial piston adjuster and rotary piston adjuster.

In the Axialkolbenverstellern the drive wheel is connected to a piston and this with the output part via helical gears in combination. The piston separates a cavity formed by the driven part and the drive wheel into two pressure chambers arranged axially relative to one another. If pressure medium is applied to one pressure chamber while the other pressure chamber is connected to a tank, the piston shifts in the axial direction. The axial displacement of the piston is translated by the Schrägver¬ zahnungen in a relative rotation of the drive wheel to the output part and thus the camshaft 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 zuein¬ other, the rotor is positively, positively or materially, for example by means of a press fit, a screw or welded connection with a camshaft, an extension of the camshaft or a Zwischen¬ wave is connected , In the stator, a plurality of circumferentially spaced cavities are formed which extend radially outward from the rotor. The cavities are pressure-tightly bounded in the axial direction by side covers. In each of these cavities, a wing connected to the rotor extends, dividing each cavity into two pressure chambers. By ge¬ targeted 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 the camshaft adjuster sensors detect the characteristics of the engine, such as the load condition and the speed. These data are fed to an electronic control unit which, after comparing the data with a characteristic data field of the internal combustion engine, controls the inflow and outflow of pressure medium to the various pressure chambers.

In order to adjust the phase position of the camshaft relative to the crankshaft, one of the two counteracting pressure chambers of one cavity is connected in hydraulic camshaft adjuster with a pressure medium pump and the other with the tank. The inflow of pressure medium to one chamber in conjunction with the discharge of pressure medium from the other chamber shifts the piston separating the pressure chambers in the axial direction, whereby the camshaft is rotated relative to the crankshaft in axial piston adjusters via the helical toothings. In Rotationskolbenverstellem is caused by the pressurization of a chamber and the pressure relief of the other chamber, a displacement of the wing and thus directly a rotation of the camshaft to the crankshaft. In order to maintain the phase position, both pressure chambers are either connected to the pressure medium pump or disconnected from the pressure medium pump as well as from the tank.

The control of the pressure medium flows to and from the pressure chambers by means of a control valve, usually a 4/3-proportional valve. A valve housing is provided with one connection each for the pressure chambers (working connection), a connection to the pressure medium pump and at least one connection to a tank. Within the substantially hollow cylindrical valve housing an axially displaceable control piston is arranged. The control piston can be brought axially into any position between two defi¬ ned end positions by means of an electromagnetic actuator against the spring force of a spring element. The control piston is further provided with ring grooves and control edges, whereby the individual pressure chambers optionally be connected to the pressure medium pump or the tank NEN. Likewise, a position of the control piston can be provided, in which the pressure medium chambers are separated from the pressure medium pump as well as from the pressure medium tank.

In DE 100 64 222 A1 such a device is shown. This is a device in rotary piston design. A standing in Antriebver¬ bond 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 covers 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 in each case two mutually opposing Druckkam¬ mers. By supplying or discharging pressure medium to and from the pressure chambers, the phase angle of the camshaft relative to the crankshaft can be selectively held or adjusted.

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 inserted into the receiving bore of the side cover. pushes and an adjustment of the rotor relative to the stator in one direction er¬ allows. In this case, the other groove in which the other Verrieglungspin still ein¬ engages, designed such that an adjustment of the rotor from the center position is made possible up to a maximum value. Accordingly, the position of the rotor relative to the stator runs in the other direction. The Vorrich¬ 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 balances the camshaft on the rotor balances.

In DE 198 53 670 A1, a control valve is shown, which is used to control the pressure medium flow to the pressure chambers depending on the current Lastzu¬ the internal combustion engine. The control valve consists of a Stell¬ unit, a substantially hollow cylindrical valve housing and a substantially hollow cylindrical running control piston, which is rather axially slidably received within the valve housing. On the valve housing two working ports, an inlet and a drain port are formed. By way of example, the actuating unit can be an electromagnet which shifts the control piston counter to the force of a spring by applying a control current via a push rod. Depending on the position of the control piston within the valve housing, the inlet connection is connected with one of the two working connections and the tank connection with the respectively other working connection or the working connections are separated from the inlet or outlet connection. As a result, a pressure chamber is supplied with pressure medium while pressure medium flows out of the other pressure chamber, which causes a change in the phase position of the camshaft relative to the crankshaft.

A serious disadvantage of this control valve in conjunction with a camshaft adjuster with center-position locking is the fact that in the de-energized state, the pressure medium connection is connected to one of the two working connections. In the case of a malfunction of the actuator so pressure medium is directed to one of the two pressure chambers and at the same time to one of the two pins. Thus, the camshaft adjuster, depending on the configuration of the control valve, after failure of the actuator in one of twisted two maximum positions and held this phase position over the entire operation of the internal combustion engine. Since the center position in which the camshaft adjuster is locked in the depressurized state of the device is selected such that the internal combustion engine has good starting and running properties relative to the crankshaft in this phase position of the camshaft, this results in a maximum phase shift relative to the center position worse starting and running characteristics of the internal combustion engine.

Summary of the invention

The invention is therefore based on the object to avoid these disadvantages and thus to propose a method by which the Nockenwel¬ le can be brought relative to the crankshaft in a phase position in which the hydraulic actuator is in a position in which this entwe- is locked or in which it is automatically brought into the locked position during the first revolution of the camshaft upon restart, without a piston or wing abutting an end stop. Furthermore, a method is to be proposed, whereby the Stellvorrich¬ device is brought in unlocked parking position in the locked position.

In a first method according to the preamble of claim 1, the object is achieved according to the invention in that the following method steps are carried out in the order listed: starting and holding a defined phase position φ + X ° CA,

- switching off the ignition,

Adjusting the second or fourth control position (130, 132) in order to maintain the phase position φ + X ° CA until the rotational speed sensor system detects the rotational speed n = 0, - detecting the rotational speed n via a rotational speed sensor,

Holding the assumed control position (130, 132) for a predetermined period of time,

- After the expiration of the period deactivating the actuator (112). 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 it is not yet sufficiently filled with pressure medium. If, for example, the device is equipped with no compensation spring or a compensating spring which effects a low rotational torque on the system rotor stator, the torque being smaller than the drag torque of the rotating camshaft, this phase position is in the direction of the center locking position in the direction of early , In the event that the compensating spring torque is greater and opposite to the camshaft drag torque, this phase position is in the direction of late relative to the central locking position due to the method steps. After Aus¬ the ignition that control position is taken, which prevents the actuator moves in the center position until a Drehzahlsenso- rik the speed n = 0 reports. Subsequently, the assumed tax settlement is maintained for a defined period of time. This is necessary since the speed sensor system already reports the rotational speed n = 0 in the last revolution of the camshaft / crankshaft and, due to the alternating torques, the actuating unit can be displaced over the center position into the undesired position. By this holding time relaxation effects of the internal combustion engine are also ab¬ catch, for example, relax piston or the like, which eben¬ if the wrong position can be taken.

In a second method according to the preamble of claim 2, the object is achieved according to the invention in that the following method steps are carried out in the listed sequence during the stopping process:

- starting and holding a defined phase position φ + X ° KW, - switching off the ignition,

Adjusting the second or fourth control position (130, 132) in order to maintain the phase position φ + X ° CA until the rotational speed sensor system detects the rotational speed n = 0, Detecting the rotational speed n via a rotational speed sensor system,

- After the expiration of the period 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, - is the fluid pressure p greater than a predetermined value: setting of control positions according to the filed in the control unit map,

This ensures that the lock, when unlocked state is reached, and the lock can be canceled only when the fluid pressure has reached a certain value and thus ausrei¬ adequate pressure medium supply of the device is ensured. As a result, a striking of a piston or wing is prevented, which would be the case with an unlocked, not sufficiently supplied with pressure means device.

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

Adjusting the first control position Detecting the 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.

Brief description of the drawings Further features of the invention emerge from the following description and from the drawings, in which exemplary embodiments of the invention are shown in simplified form. Show it:

1 shows a longitudinal section through a hydraulic Stellvorrich¬ device,

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

FIG. 3 shows a flowchart for a method for starting an internal combustion engine with a device according to the invention for changing the control times of gas exchange valves,

FIG. 4 shows a schematic illustration of a device according to the invention for changing the control times of gas exchange valves of an internal combustion engine,

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

FIG. 5b shows a longitudinal section through the control valve from FIG. 5a in a second control position,

FIG. 5c shows a longitudinal section through the control valve from FIG. 5a in a third control position,

FIG. 5d shows a longitudinal section through the control valve from FIG. 5a in a fourth control position, FIG. 6 shows in a diagram the volume flow from the inlet connection to the pressure chambers as a function of the position of the control piston relative to the valve housing,

FIG. 7 is a flow chart 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

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

Detailed description of the drawing

Figures 1 and 2 show a hydraulic adjusting device 1a of a Vor¬ device 1 for changing the timing of gas exchange valves of an internal combustion engine. The adjusting device 1a consists essentially of a stator 2 and a rotor 3 arranged concentrically therewith. A drive wheel 4 is connected in a rotationally fixed manner to the stator 2 and, in the illustrated embodiment, is designed as a chain wheel. Likewise conceivable are embodiments of the drive wheel 4 as a belt or gear. The stator 2 is rotatably mounted on the rotor 3, wherein on the inner circumferential surface of the stator 2 in the illustrated embodiment, five circumferentially spaced recesses 5 are provided. The recesses 5 are bounded in the radial direction by the stator 2 and the rotor 3, in the circumferential direction of two Seiten¬ walls 6 of the stator 2 and in the axial direction by a first and a second side cover 7, 8. Each of the recesses 5 is sealed pressure-tight manner in this way. The first and second side covers 7, 8 are connected to the stator 2 by means of connecting elements 9, for example screws. On the outer circumferential surface of the rotor 3 axially extending vane grooves 10 are formed, wherein in each vane groove 10, a radially extending vane 11 is arranged. In each recess 5, a wing 11 extends, wherein the wings 11 in the radial direction on the stator 2 and in the axial direction on the side tende 7, 8 abut. Each vane 11 divides a recess 5 into two pressure chambers 12, 13 working against each other. In order to ensure a pressure-tight abutment of the vanes 11 on the stator 2, leaf spring elements 15 are provided between the groove green 14 of the vane grooves 10 and the vanes 11 , which act on the wing 11 in the radial direction with a force.

By means of first and second pressure medium lines 16, 17, the first and second pressure chambers 12, 13 can be connected via a control valve (not shown) to a pressure medium pump (also not shown) or to a tank (also not shown). As a result, an actuator is formed, which makes a relative rotation of the stator 2 with respect to the rotor 3 possible. It is provided that either all the first pressure chambers 12 are connected to the pressure medium pump and all second pressure chambers 13 are connected to the tank or the configuration opposite to that. If the first pressure chambers 12 are connected to the pressure medium pump and the second pressure chambers 13 are connected to the tank, then the first pressure chambers 12 expand at the expense of the second pressure chambers 13. This results in a displacement of the wings 11 in the circumferential direction, in the direction indicated by the first arrow 21. By moving the vanes 11, the rotor 3 is rotated relative to the stator 2.

In the illustrated embodiment, the stator 2 is driven by the crank shaft by means of a chain drive (not shown) acting on its drive wheel 4. Also conceivable is the drive of the stator 2 by means of a belt or gear drive. The rotor 3 is non-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 Relatiwerdrehung of the rotor 3 relative to the stator 2, as a result of the supply and discharge of pressure medium to or from the pressure chambers 12, 13, resulting performs a phase shift between camshaft and crankshaft. By deliberately introducing or removing pressure medium into the pressure chambers 12, 13, the control times of the gas exchange valves of the internal combustion engine can thus be selectively varied.

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

The substantially radially extending side walls 6 of the recesses 5 are provided with formations 23 which extend in the circumferential direction into the recesses 5. 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 assumes one of its two extreme positions relative to the stator 2, in which the wings 11 on one of Side walls 6 abut.

With insufficient supply of pressure medium of the device 1, for example, during the starting phase of the internal combustion engine, the rotor 3 is due to the alternating and drag torque that exerts the camshaft on this un¬ controlled relative to the stator 2 moves. 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 they strike against the side walls 6. In the following, the Wechselmo¬ elements that exerts the camshaft on the rotor 3 to a back and forth swing of the rotor 3 and thus the wing 11 in the recesses 5, to at least one of the pressure chambers 12, 13 is completely filled with pressure medium. This leads to higher wear and noise development in the device 1. To prevent this, two locking elements 24 are provided in the device 1. Each locking element 24 consists of a cup-shaped piston 26, which is arranged in an axial bore 25 of the rotor 3. The piston 26 is acted upon by a spring 27 in the axial direction with a force. The spring 27 is supported in the axial direction on one side on a venting element 28 and is arranged with its axial end facing away from it inside the pot-shaped piston 26.

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

In order to be able to derive leakage oil from the spring chamber of the axial bore 25, the venting element 28 is provided with axially extending grooves along which the pressure medium can be conducted to a bore in the second side cover 8. Figure 8 shows a device 101 for changing the timing of Gas¬ interchange valves of an internal combustion engine from the prior art. This consists of a hydraulic adjusting device 102 and a control valve 103. The adjusting device 102 consists of a pressure chamber 104, which is divided by a ver¬ sliding element 105 into two oppositely acting pressure chambers 106, 107. The displaceable element 105 is connected in a rotationally fixed manner to the camshaft or the crankshaft, while the other component is connected in a rotationally fixed manner to the pressure chamber 104. The displaceable element 105 is immovably connected to two scenes 108, 109. Furthermore, 110 and 111 respectively denotes a locking pin, wherein these are fixedly mounted to the pressure chamber 104. Each link 108, 109 is each assigned a locking pin 110, 111. Alternatively, the locking pins 110, 111 can move with the element 105 and the scenes 108, 109 may be formed in a stationary to the pressure chamber 104 component.

The control valve 103 consists of an actuating unit 112, a first spring element 113 and a valve body 114. The actuating unit 112 can be embodied, for example, in the form of an electric or hydraulic actuating unit 112. In the following, an electrical actuator 112 is to be assumed without limiting the generality, which is designed as an electromagnet. On the valve body 114, a first working port A, a second working port B, an inflow port P and a discharge port T are formed. The first working port A is connected via a first pressure medium line 115 to 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 outlet connection T is connected to a pressure medium reservoir 117. Via a pressure medium pump 118, a filter 119 and a return check valve 120, the inlet port P is acted upon by pressure medium. Via a third pressure medium line 121, the first link 108 is in communication with the first pressure medium line 115. Likewise, the second link 109 is a fourth pressure medium line 122 in connection with the second Druckmittellei¬ device 116. The first and second link 108, 109 are each as a groove formed, wherein the dimension thereof in the direction of movement of the movable E lements 105 is greater than that of the respective Verrieglungspins 110, 111. Both locking pins 110, 111 engage in the illustrated center position of the displaceable element 105 in the respective link 108, 109 and are in Displacement direction of the movable member 105 disposed at one end of the jeweili¬ gen groove.

By means of the adjusting unit 112, the valve against the spring force of the first spring element 113 in a second, a third and a fourth control position 130, 131, 132 are brought. If the valve is located in the second control position 130, which is the case for low to no energization of the setting unit 112, the second working connection B is connected exclusively to the inlet connection P and the first working connection A is connected exclusively to the outflow connection T. If the valve is in the third control position 131, which is the case with low to medium energization of the setting unit 112, both working connections A, B are connected neither to the inlet connection P nor to the outlet connection 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 located in the fourth control position 132, which is the case with average to maximum energization of the setting unit 112, the first working connection A is connected exclusively to the inlet connection P and the second working connection B is connected exclusively to the outlet connection T.

During controlled operation of the internal combustion engine, the control valve 103 is brought into the second control position 130 in order to achieve an adjustment of the movable element 105 in the direction of late, characterized by the second arrow 126. Pressure medium is passed from the inlet connection P via the second work connection B and the second pressure medium line 116 to the second pressure chamber 107. At the same time 122 pressure medium is passed into the second gate 109 via the fourth pressure medium line. As a result, the second locking pin 111 is urged against the force of a second spring 129 from the second link 109. At the same time, the first pressure chamber 106 is connected to the pressure medium reservoir 117 via the first pressure medium line 115 and the discharge port T. As a result of the outflow of pressure medium from the first pressure chamber 106 and the inflow of pressure medium to the second pressure chamber 107, the movable element 105 is displaced in the direction of late. At the same time, the first and the second gate 108, 109 are also moved late. In this case, the first locking pin 110 moves within the first link 108, while the second locking pin 111 is located outside the second link 109. In order to maintain a phase angle φ of the hydraulic actuator 102, the control valve 103 is brought into the third control position 131. Both working connections A, B are connected neither to the inlet P nor to the outlet connection T, there is no inflow or outflow of pressure medium to or from the pressure chambers 106, 107 and the phase position φ is kept constant. In order to achieve an adjustment of the movable element 105 in the direction early, characterized by the third arrow 128, the control valve 103 is brought into the fourth control position 132. Pressure medium is passed from the inlet port P via the first working port A and the first pressure medium line 115 to the first pressure chamber 106. At the same time, pressure medium is conducted into the first slide 108 via the third pressure medium line 121. As a result, the first locking pin 110 is urged against the force of a first spring 127 from the first link 108. At the same time, the second pressure chamber 107 is connected to the pressure medium reservoir 117 via the second pressure medium line 116 and the discharge port T. As a result of the outflow of pressure medium from the second pressure chamber 107 and the inflow of pressure medium to the first pressure chamber 106, the movable element 105 is displaced in the direction of early. At the same time, the first and the second scenery 108, 109 are also shifted in the direction of early. In this case, the second locking pin 111 moves within the second link 109, while the first locking pin 110 is located outside the first link 108.

If the movable element 105 is displaced beyond the center position from a position that deviates from the center position shown in FIG. 8, then the locking pin 110, 111, which is not subjected to pressure medium, locks in place respective backdrop 108, 109 a. At the same time, the other locking pin 110, 111 is acted upon by pressure medium so that it is outside the gate 108, 109. The movement is limited only by the latched locking pin 110, 111. If the hydraulic adjusting device 102 is in the middle position shown in FIG. 8 and the device 101 is not supplied with sufficient pressure medium, which is the case, for example, when starting the internal combustion engine, then both locking pins in 110, 111 are in the respective one Setting 108, 109 engaged. In this case, the locking pins 110, 111 are arranged in such a way and the scenes 108, 109 designed such that the Verrieglungspins 110, 111 are located at the ends of the scenes 108, 109, which are farthest from each other. As a result, the movable element 105 is fixed relative to the pressure chamber 104. Alternatively, the locking pins 110, 111 may be at the ends of the scenes 108, 109 that are closest to each other. In this alternative embodiment, the first link 108 would have to be acted upon by the second pressure medium line 116 and the second link 109 of the first pressure medium line 115 with pressure medium. Also conceivable is an action on the scenes 108, 109 via the respective pressure chamber 106, 107, for example by means of a worm groove.

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

If the actuating unit 112 of the control valve 103 fails, the power supply is interrupted, for example, by a defect in the electromagnet or the power connections, the control valve 103 is set in the second control position 130. As a result, the second locking pin 111 is unlocked and the camshaft is retarded relative to the crankshaft. is presented. This has the consequence that the starting and running properties of the internal combustion engine, which are optimal in the center position shown in Figure 8, deteriorate.

The schematically illustrated hydraulic adjusting device 102 may be, for example, an axial piston adjuster or a rotary piston adjuster. In the following, without restriction of the generality, only the embodiment of a rotary piston adjuster is to be treated. The pressure chamber 104 corresponds to the recesses 5 from FIG. 1. The movable element 105 can be used in the embodiment of FIG. 1 either in a side cover of the rotary piston adjuster or in the rotor of the rotary piston adjuster inside a bore. preferably a blind hole, be arranged. The respective scenes 108, 109 are formed in the respective other component.

In FIG. 4, a device 101 according to the invention is shown schematically, analogously to FIG. 8. This is largely identical to that shown in FIG. 8, which is why the same reference numbers were used for the same components. The difference of the device 101 according to the invention is that the control valve 103 additionally has a first control position 140. The first control position 140 is activated when the actuator 112 assumes a state corresponding to a low to no energization. The first spring element 113 ensures in this case that the first control position 140 is reached. In this position, neither the first nor the second Arbeitsanschi uss A, B connected to the inlet port P. Depending on the configuration of the hydraulic adjusting device 102, either the first or the second working port A, B can now be connected to the discharge port T, while the other working port A, B does not communicate with the drain port T. Also conceivable is an embodiment in which, in the first control position 140, the first and the second working connection A, B communicate neither with the inlet connection P nor with the outlet connection T or both working connections A, B are exclusively connected with the outlet connection T. , In addition to the first control position 140, the control valve 103 likewise has the second, third and fourth control positions 103, 131, 132 shown in FIG. 8, the second control position 130 at a low to medium supply, the third control position 131 at a middle to high energization and the fourth control position 132 at a high to maximum current, the actuator 112 is taken.

In the case of a defect of the actuator 112 or an error in the Strom¬ supply the control valve 103 automatically enters the first control position 140, wherein the switching valve 103 holds this position until the repair of the unit 112 and their power supply. After a restart of the internal combustion engine 102, the movable member 105 is inde pendent of its position on the switching off of the internal combustion engine due to the drag and alternating moments moved into the middle position due to the insufficient pressure medium supply. There, both locking pins 110, 111 in the respective link 108, 109 einriegeln, whereby the position of the movable member 105 is fixed in the pressure chamber 104. Due to the configuration of the first control position 140, no pressure medium is supplied to the pressure chambers 106, 107 and thus to the scenes 108, 109 during operation of the internal combustion engine. This has the consequence that the movable element 105 is held stationary relative to the pressure chamber 104 and thus the phase angle φ between the camshaft and crankshaft is kept constant in the emergency running position in which the internal combustion engine has good starting and running properties.

FIGS. 5a to 5d show, by way of example, a valve body 114 of a control valve 103 of a device 101 according to the invention. The valve body 114 consists of a valve housing 141 and a control piston 142. The valve housing 141 is substantially hollow-cylindrical, with three axially extending in its outer lateral surface spaced annular grooves 143, 144, 145 are formed. Each of the annular grooves 143 to 145 constitutes a connection of the valve, wherein the outer ring grooves 143, 145 in the axial direction form the working connections A, B and the middle annular groove 144 forms the inlet connection P. A discharge connection T is through an opening in one end face of the valve housing ses 141 executed. Each of the annular grooves 143 to 145 is connected to the inner of the valve housing 141 via first radial openings 146. Inside the valve housing 141, a substantially hollow-cylindrical executed control piston 142 is arranged axially displaceable. The control piston 142 is acted on by a second spring element 147 on one end face and by a push rod 148 of the setting unit 112 with a force on the opposite end face. By energizing the actuating unit 112, the control piston 142 can be displaced against the force of the second spring element 147 into an arbitrary position between a first and a second end stop 149, 150.

The control piston 142 is provided with a first and a second annular web 151, 152. The outer diameters of the annular webs 151, 152 are adapted to the inner diameter of the valve housing 141. Furthermore, in the control piston 142 between the frontal end, on which the push rod 148 engages, and the second annular web 152 second radial openings 146a are formed, whereby the interior of the control piston 142 is in communication with the interior of the valve housing 141. The first and second annular ribs 151, 152 are designed and arranged on the outer lateral surface of the control piston 142 such that control edges 153 to 156, depending on the position of the control piston 142 relative to the valve housing 141, form a connection between the inlet connection 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 made smaller in the regions between the push rod 148 and the second annular web 152 and between the first annular web 151 and the second annular web 152 than the inner diameter of the valve housing 141. As a result, between the first and the second annular web 151 , 152 a fourth annular groove 157 is formed. Within the fourth annular groove 157, a third annular rib 158 is formed. The outer diameter of the third annular web 158 is adapted to the inner diameter of the valve housing 141. Furthermore, the third annular web 158 is positioned such that in the first control position 140 of the control valve 103 it blocks the connection between the supply port P and the second working port B. 5a shows the first control position 140 of the control valve 103, in which the control piston 142 is acted upon by the adjusting unit 112 via the push rod 148 with a force between a minimum force and a small F ₁ . The push rod-side end face of the control piston 142 is located in a region between the first end stop 149 (displacement distance = 0 mm) and a displacement path si. The connection between the inlet port P and the second Arbeitsanschi uss B is blocked by 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. Furthermore, the connection between the second working connection B and the discharge connection T is blocked by means of the second annular web 152, while pressure medium can flow from the first working connection A to the discharge connection T. Since the pressure medium flow to the locking pins 110, 111 and to both pressure chambers 106, 107 is blocked, no active adjustment can take place in the first control position 140. By the connection of the first pressure chamber 106 with the reservoir 11, this is emptied. Depending on the position of the hydraulic actuating device 102, the movable element 105 is immediately, or after a certain time, required to empty the second pressure chamber 107 due to leakage due to drag or alternating torques of the camshaft driven into the center position and locked there permanently. This control position corresponds to a configuration of the control valve 103 in which the actuator 112 is de-energized and consequently the control piston 142 is displaced by means of the second spring element 147 to the first end stop 149, the displacement is thus zero. In this position, the valve is when the actuator 112 is defective or their power supply is interrupted.

FIG. 5 b shows the second control position 130 of the control valve 103, in which the control piston 142 is acted upon by the setting unit 112 via the push rod 148 with a force between a small force F ₁ and an average force F ₂ , where F ₂ > F ₁ . As a result, the control piston 142 is displaced by a distance S ₁ to S ₂ from the push rod-side first end stop 149, S ₂ > S ₁ . The first ring land 151 still blocks the connection between the first working port A and the inlet port P, while pressure fluid from the first work to the outlet port T can continue to flow. Furthermore, the second annular rib 152 blocks the connection between the second working port B and the drain port T, while both the second and the third annular ribs 152, 158 release a connection between the inflow port P and the second working port B. In this position, pressure medium is supplied via the second working port B, the second and fourth pressure medium lines 116, 122 to the second pressure chamber 107 and the second link 109, whereby the second locking pin 111 is unlocked and the hydraulic actuating device 102 moves laterally. At the same time, pressure medium flows from the first pressure chamber 106 via the first pressure medium line 115 to the first working port A and from there to the discharge port T.

FIG. 5c shows the third control position 131 of the control valve 103, in which the control piston 142 is acted upon by the setting unit 112 via the push rod 148 with a force between a middle F ₂ and a large force F ₃ , where F ₃ > F ₂ . As a result, the control piston 142 is displaced by a distance S ₂ to S ₃ from the push rod-side first end stop 149, S ₃ > S ₂ . In this position of the switching valve, the first and the second annular web 151, 152 block 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 is neither pressure means supplied to the pressure chambers 106, 107, nor can pressure fluid from the pressure chambers 106, 107 flow away. This control position thus corresponds to a holding position in which the phase angle φ between camshaft and crankshaft is kept constant.

FIG. 5 d shows the fourth control position 132 of the control valve 103, in which the control piston 142 is acted upon by the setting unit 112 via the push rod 148 with a force between a large force F ₃ and a maximum force F ₄ , where F ₄ > F ₃ , As a result, the control piston 142 is displaced by a distance S ₃ to S ₄ from the push rod-side first end stop 149, whereby at S ₄ > S ₃ . In this configuration, the first ring land 151 blocks 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 is blocked by both the first ring land 151 and the third ring land 158 is released. Furthermore, the connection between the inlet port P and the second working port B is blocked by the second annular web 152, while pressure fluid can reach the interior of the control piston 142 and from there to the outlet port T via the second working port B and the second radial ports 146a. In this position, the control valve 103 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 is passed. At the same time, the first pressure medium line 115 and the third pressure medium line 121 are supplied with pressure medium to the first pressure chamber 106 and the first slide 108 via the first working connection A. Thereby, the first locking pin 110 is unlocked and the hydraulic actuator 102 moves to early.

By using the described 4/4-way valve, as the control valve 103 of the device 101 according to the invention, no additional modules, such as additional control valves needed to represent a device 101 with center-position locking, which starts automatically in a locked center position, wherein an abutment of the element 105 (wing on wing cell 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, if the setting unit 112 fails, the device 101 is brought into the center position and locked there until the setting unit 112 is repaired.

FIG. 6 shows the volume flow from the inlet connection T to the pressure chambers 106, 107 as a function of the duty cycle of the setting unit 112. The setting unit 112 can be subjected to a voltage, with either zero volts or a maximum value being applied. The duty cycle indicates the proportion of time in which the maximum value of the voltage at the actuator 112th is applied. The higher the duty cycle, the higher the force exerted by the positioning unit 112 on the control piston 142 via the push rod 148. Thus, the duty cycle is a measure of the displacement of the Steuerkol¬ bens 142 within the valve housing 141 relative to the first end stop 149th

In a first region in which the duty cycle lies between zero and a first value TV 1, the control valve 103 assumes the first control position 140. In this control position 140, the connections between the inlet connection P and the working connections A, B are blocked, the volume flow is apart from leakage flows 0.

If the duty cycle lies between a first value TV 1 and a second value TV 2, the control valve 103 is in the second control position 130. Pressure medium can reach the second working port B from the inlet port P, while the connection between the inlet port P and the first working port A Is blocked. The volumetric flow increases steadily as the duty cycle increases from a first value TV 1 to a third value TV 3, while when increasing further up to the second value TV 2 it steadily decreases and finally near the value TV 2 it is close to zero. Advantageously, only the area between TV3 and TV2 is used for the second control position 130.

In a third area between the value TV 2 and a value TV 4, duty cycle ratios which lie in this range are referred to below as the hold load 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 ports A, B are not in connection with the inlet port P.

If the value of the duty cycle, starting from the value TV 4, is further increased to 100%, then the volume flow from the feed port P to the pressure chamber 106, 107 initially increases steadily. The volumetric flow can increase steadily up to a duty cycle 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 the pressure medium from the inlet port P to the first Arbeitsanschi A is guided while the connection between the supply port P and the second working port B is blocked.

In addition to the advantage that in case of failure of the actuator 112 at a restart of the internal combustion engine, the hydraulic actuator 102 is locked in a central position and this lock is held, the inventive device 101 allows for intact actuator 112 locking the hydraulic actuator 102 in the center position when switching off the internal combustion engine or a positioning of the hydraulic Stellvorrich- device 102 such that when restarting the internal combustion engine, the hydraulic actuator 102 is brought into the center position and locked there. This has the advantage that during the starting operation, in which the device 101 is not yet sufficiently filled with pressure medium, the hydraulic adjusting device 102 is securely locked in the center position, whereby a striking of the displaceable element 105 on a side wall of the pressure ¬ space 104 is avoided, whereby increased wear and Geräuschent¬ development is avoided.

To operate the internal combustion engine, the various duty cycles, in particular TV1 to TV3, and the Haitetastverhältnis TV _Ha it _e must be known to the Mo torsteuergerät. The Haitetastverhältnis is determined by default by the engine control unit and stored in a storage unit. For the determination of TV1, TV2 and TV3 two possibilities are conceivable. The structural design and the resulting valve characteristics can be used to determine TV1, TV2 and TV3 in direct dependence on the Haitetast ratio TV _Ha i _te . The difference angles Y ₁ , Y ₂ and Y ₃ are stored permanently in a memory unit. The engine control unit determines the Haitetastverhältnis TV _Ha ιte- For TV1 in an early Phase se of the operation of the internal combustion engine. TV2 and TV3 then apply:

TV1 = TV _Ha ), e-Y1, TV2 = TV _H old "Y2, TV3 = TV _Ha -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. For the determination of 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 process starts (at this point one of the pressure chambers 106, 107 and a locking pin 110, 111 is acted upon by pressure medium and the hydraulic adjusting device adjusted, which is detected by camshaft angle sensors and crankshaft angle sensors can be). 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.

FIG. 7 shows a flowchart of a method for controlling the device 101 according to the invention during a stopping operation of the internal combustion engine, by which the hydraulic adjusting device 102 is brought into a position in which it is either locked after the stop of the internal combustion engine or in one Position is from which it is moved after the restart of the internal combustion engine directly in the center position and locked there ver¬. 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 brought by means of the control valve 103 in a Abstellphasenlage which differs by a defined amount X of the locking phase position φ _M itt _e . The Ab¬ stellphasenlage is for a device 101, which is designed without compensation spring, relative to the locking phase position φ _M i _tt e moved early. The same applies to a device 101 which is equipped with a Kompensations¬ 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 No camshaft, the parking phase is relative to the locking phase position φ _M i _tte shifted late. If the predetermined Abstellphasenlage reached so the ignition is turned off and the value of the duty cycle is der¬ art set that this phase φ is held securely. In the case of an adjustment of a postponed Abstellphasenlage the Tastver¬ ratio is therefore between TV 2 and 100%, in the case of a Abstellphasenlage wel¬ che relative to the Verrieglungsphasenlage φ _M itte retarded is between TV 4 and TV3. This duty cycle is maintained until the Drehzahlsen¬ sensors report the speed zero. Thereafter, the set duty cycle is held for a certain period Y before finally the actuator 112 is kept de-energized. The holding time of Y prevents the locking pins 110, 111 from being unlocked during the last revolution of the internal combustion engine, during which the rotational speed sensor already supplies the rotational speed n = 0, and the movable element 105 due to pressure fluctuations due to the changeover moments is pushed over the center position in the wrong position.

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

3 shows a flow chart of a method for starting a combustion engine with a device 101 according to the invention, by which it is ensured that an already existing or a locking of the movable element 105 produced during the first revolution of the crankshaft is held, until the oil pressure within the internal combustion engine has risen to a value which is required for safe operation of the device 101. At the beginning of the starting process, the speed n and the duty cycle are equal to zero. As long as the speed sensor reports a speed n = zero, the duty cycle is kept between zero% and the value TV 1. 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 pmin, which is necessary for the device according to the invention 101, the value of the duty cycle is kept between zero% and the value TV 1. If the oil pressure p exceeds the predetermined pressure, the device 101 changes over to controlled operation and the duty cycle is adjusted between TV 3 and 100%, depending on the load condition of the machine.

The aforementioned embodiments are only exemplary. Of course, the Arbeits¬ connections A, B are interchangeable. Also included in the scope are devices 101 mitteniagenverriegelung the hydraulic see actuator 102, with only one locking pin can engage in a backdrop or a stepped backdrop. Likewise, devices with an arbitrary Verrieglungsphasenlage with one or more locking pins. When considering the volumetric flows and the connections between different connections of the switching valve, pressure losses due to leakage were neglected.

reference numeral

Device 102 hydraulic adjusting device hydraulic adjusting device 103 control valve

Stator 104 pressure chamber

Rotor 105 element

Drive gear 106 first pressure chamber

Recesses 107 second pressure chamber

Side wall 108 first backdrop first side cover 109 second backdrop second side cover 110 first locking pin

Connecting element 111 second locking pin

Wing groove 112 actuator

Wing 113 first spring element first pressure chamber 114 valve body second pressure chamber 115 first pressure medium line

Groove base 116 second pressure medium line

Leaf spring element 117 Pressure medium reservoir first pressure medium line 118 Pressure medium pump second pressure medium line 119 Filter first arrow 120 Check valve

Central bore 121 third pressure medium line

Formations 122 fourth pressure medium line

Locking element 126 second arrow

Axial bore 127 first spring

Piston 128 third arrow

Spring 129 second spring

Venting element 130 second control position

Gate 131 third control position

Recess 132 fourth control position

Device 133 Late stop 140 first control position

141 Valve body

142 control piston

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 annular groove

158 third ring walkway

P inlet connection

T drain connection

A first work connection

B second working connection φ phase position φmitte locking phase position

X amount

Yi difference angle

Y ₂ difference angle

Y ₃ difference angle

T TVViH-iaalittee H Haaiitteettaassttvveerrhhäälltnniiss p _min oil pressure

Claims

claims

1. A method for controlling a device (101) for changing the timing of gas exchange valves of an internal combustion engine during the stopping operation of the internal combustion engine with

a hydraulic adjusting device (102) which has two pressure chambers (106, 107) acting against each other,

- By feeding and discharging 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 changed specifically,

- And with a control valve (103) with two working ports (A, B), a drain (T) and an inlet 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 ei¬ nem tank and the inlet port (P) is acted upon with pressure medium,

- wherein the control valve (103) by means of an actuating unit (112) in four Steuer¬ settings (103, 131, 132, 140) can be brought, - wherein in a first control position (140) of the control valve (103), neither the first working port (A ) still the second working port (B) communicates with the inlet port (P),

in a second control position (130) of the control valve (103) the first working connection (A) communicates with the outlet connection (T) and the second working connection (B) communicates with the inlet connection (P),

- In a third control position (131) of the control valve (103) the first and the second working port (A, B) communicates neither with the drain port (T) nor with the inlet port (P) or the first and the second working port (A, B ) communicated exclusively with the inlet connection (P),

in a fourth control position (132) of the control valve (103), the second work connection (B) communicates with the outlet connection (T) and the first work connection (A) communicates with the inlet connection (P); records 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) in order to maintain the phase position φ + X ° CA until the rotational speed sensor system detects the rotational speed n = 0,

Detecting the rotational speed n via a rotational speed sensor, holding the assumed control position (130, 132) for a predetermined period of time,

- After the expiration of the period deactivating the actuator (112).

2. A 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

wherein a phase angle (φ) of a camshaft relative to a crankshaft can be held or selectively changed by supplying and removing pressure medium to and from the pressure chambers (106, 107),

- And with a control valve (103) with two working ports (A, B), a drain (T) and an inlet 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) can be brought into four control positions (103, 131, 132, 140) by means of an actuating unit (112),

wherein in a first control position (140) of the control valve (103), neither the first working port (A) nor the second working port (B) communicates with the inflow port (P), in a second control position (130) of the control valve (103), the first work connection (A) communicates with the drain connection (T) and the second work connection (B) communicates with the inlet connection (P),

- In a third control position (131) of the control valve (103) the first and the second working port (A, B) communicates neither with the drain port (T) nor with the inlet port (P) or the first and the second working port (A, B ) communicates exclusively with the inlet connection (P),

in a fourth control position (132) of the control valve (103), the second working port (B) communicates with the outlet port (T) and the first working port (A) communicates with the inlet port (P), characterized in that the following process steps are carried out in the order listed:

Setting the first control position - detection of the speed n of the crankshaft or the camshaft,

is the rotational speed n> 0: detection of the fluid pressure p,

3. A method for controlling a device (101) for changing the timing of gas exchange valves of an internal combustion engine with

Crankshaft held or can be changed specifically,

- And with a control valve (103) with two working ports (A, B), a drain (T) and an inlet port (P), wherein the first Arbeitsan¬ circuit (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 ei¬ nem tank and the inlet port (P) is acted upon with pressure medium, wherein the control valve (103) can be brought into four control positions (103, 131, 132, 140) by means of an actuating unit (112),

wherein in a first control position (140) of the control valve (103), neither the first working port (A) nor the second working port (B) communicates with the inflow port (P),

in a fourth control position (132) of the control valve (103), the second working port (B) communicates with the outlet port (T) and the first working port (A) communicates with the inlet port (P), characterized in that the following process steps are carried out in the order listed during the stop process:

Adjusting the second or fourth control position (130, 132) in order to maintain the phase position φ + X ° CA until the rotational speed sensor system detects the rotational speed n = 0,

after the lapse of time, deactivating the setting unit (112), and that the following method steps are carried out in the order listed during the starting procedure: - setting of 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 stored in the control unit map.