Abstract:
A hydraulic control valve ( 1 ) for controlling the flow of a pressure medium, having at least one drain port (T 1 , T 2 ) communicating with a tank, at least one inflow port (P) communicating with a pressure medium source, and at least two supply ports (V 1 , V 2 , V 3 ) communicating with at least one hydraulic consumer.

Description:
BACKGROUND 
       [0001]    The invention relates to a hydraulic control valve for controlling pressure medium flows. 
         [0002]    In modern internal combustion engines, hydraulic control valves, in particular, proportional valves in a directional control slide valve construction are used for controlling a plurality of hydraulic loads. The control valve is made from an essentially hollow cylindrical valve housing and an axial displaceable control piston arranged therein. Here, pressure medium is fed to the control valve via at least one inflow port. Furthermore, the control valve has available one or more supply ports that are connected hydraulically to the load. In addition, at least one outflow port is provided by which pressure medium can be discharged from the control valve into a tank. As a function of the position of the control piston relative to the valve housing, pressure medium is supplied to one or more supply ports or discharged from these ports into the tank. 
         [0003]    A consumer controlled by a control valve is, for example, a device for variable adjustment of the control times of gas-exchange valves of an internal combustion engine (camshaft adjuster). Camshaft adjusters are used to be able to variably construct the phase relation between the crankshaft and camshaft of an internal combustion engine in a defined angular range between a maximum advanced position and a maximum retarded position. For this purpose, the device is integrated into a drive train by which torque is transmitted from the crankshaft to the camshaft. This drive train can be realized, for example, as a belt, chain, or gear drive. 
         [0004]    Such devices comprise at least two rotors that can rotate in opposite directions, wherein one rotor is in driven connection with the crankshaft and the other rotor is locked in rotation with the camshaft. The device comprises at least one pressure space that is divided by a movable element into two pressure chambers acting against each other. The moving element is in active connection with at least one of the rotors. By supplying pressure medium to or discharging pressure medium from the pressure chambers, the moving element is shifted within the pressure space, whereby a desired rotation of the rotors relative to each other and thus the camshaft relative to the crankshaft is realized. 
         [0005]    The inflow of pressure medium to or the outflow of pressure medium from the pressure chambers is controlled by a hydraulic control valve. Here, two supply ports (work ports) of which each communicates with a pressure chamber of each pressure space are formed on the control valve. 
         [0006]    The control valve is controlled by a regulator that determines the actual and desired positions of the camshaft of the internal combustion engine with the help of sensors and compares these positions with each other. Once a difference between both positions is determined, a signal is transmitted to the regulator that adjusts the position of the control piston relative to the valve housing of the control valve based on the signal and in this way regulates the pressure medium flows to the pressure chambers. 
         [0007]    In order to guarantee the function of the device, the pressure in the pressure medium circuit of the internal combustion engine must exceed a certain value. Because the pressure medium is usually provided by the oil pump of the internal combustion engine and the provided pressure thus increases in sync with the rotational speed of the internal combustion engine, below a certain rotational speed the oil pressure is still too low, in order to change or hold the phase position of the rotors in a desired manner. This can be the case, for example, during the startup phase of the internal combustion engine or during the idling phase. 
         [0008]    During these phases the device would carry out uncontrolled vibrations, which leads to increased noise emissions, increased wear, non-smooth running, and increased raw emissions of the internal combustion engine. To prevent this, mechanical locking devices can be provided that couple the two rotors to each other locked in rotation during the critical operating phases of the internal combustion engine, wherein this coupling can be canceled by applying pressure medium to the locking device. Here it has emerged to be advantageous to be able to influence the locking state of the device and thus the pressure medium supply to or the pressure medium discharge from the locking device, independent of the pressure relationships in the pressure chambers. 
         [0009]    This is realized by a control valve that has, in addition to the two work connections that are connected to the pressure chambers, another supply port (control port) that communicates with the locking device. 
         [0010]    Such a device and such a control valve are known, for example, from US 2003/0121486 A1. In this embodiment, the device has a rotary piston type construction, wherein an outer rotor is supported so that it can rotate on an inner rotor constructed as an impeller wheel. In addition, two rotational angle limiting devices are provided, wherein a first rotational angle limiting device in the locked state allows an adjustment of the inner rotor relative to the outer rotor in an interval between a maximum retarded position and a defined middle position (locking position). The second rotational angle limiting device allows, in the locked state, a rotation of the inner rotor to the outer rotor in an interval between the middle position and the maximum advanced position. If both rotational angle limiting devices are located in the locked state, then the phase position of the inner rotor to the outer rotor is limited to the locking position. 
         [0011]    Each of the rotational angle limiting devices is made from a spring-loaded locking pin that is arranged in a receptacle of the outer rotor. Each locking pin is loaded with a force via a spring in the direction of the inner rotor. A locking groove that is opposite the locking pins in certain operating positions of the devices is formed on the inner rotor. In these operating positions, the pins can engage in the locking groove. In this way, the appropriate rotational angle limiting device transitions from an unlocked into a locked state. 
         [0012]    Each of the rotational angle limiting devices can be changed from the locked state into the unlocked state by pressure medium loading of the locking groove. In this case, the pressure medium forces the locking pins back into their receptacle, by which the mechanical coupling of the inner rotor to the outer rotor is canceled. 
         [0013]    The pressure medium loading of the pressure chambers and the locking grooves is realized by a control valve, wherein on the control valve, among other things, two work ports that communicate with the pressure chambers and one control port that communicates with the locking groove are formed. The control valve has two supply ports. One of the supply ports can be connected exclusively to the control port, while pressure medium can reach exclusively to the work ports by the other supply port. In this embodiment, the high installation space requirements of the control valve due to the plurality of ports are disadvantageous. The embodiment corresponds to two control valves arranged in series that have available a common control piston. This construction considerably limits the possibilities of control logic that can be realized in comparison to two separate control valves. More flexible or more complex control logic, primarily with respect to the control port, can be represented only with considerable consequences for the installation space requirements of the control valve. 
       SUMMARY 
       [0014]    The invention is based on the objective of providing an installation space-optimized control valve that can control the pressure medium flow to or from several supply lines via several supply ports, wherein the resulting device should have a high degree of freedom for the realization of a wide range of control logic. 
         [0015]    In a first embodiment, a hydraulic control valve with an essentially hollow cylindrical valve housing on which at least one inflow port, at least one outflow port, and at least two supply ports are formed and with a control piston that is arranged within the valve housing and that can move axially relative to this housing, wherein first control elements are formed on an essentially cylindrical lateral surface of one of the two components within a first region extending in the axial and peripheral direction and second control elements are formed within a second region extending in the axial and peripheral direction, wherein counter control elements are formed on the other component, wherein the first control elements interact with the counter control elements such that a pressure medium flow between the first supply port and the interior of the valve housing is controlled as a function of the axial position of the components relative to each other, wherein the second control elements interact with the counter control elements such that a pressure medium flow between the second supply port and the interior of the valve housing is controlled as a function of the axial position of the components relative to each other, the objective is met according to the invention in that the first and the second region are arranged at least partially overlapping in the axial direction, that the first region extends in the peripheral direction of the control valve within a first angular region, and that the second region extends in the peripheral direction of the control valve within a second angular region, wherein the regions do not overlap in the peripheral direction. 
         [0016]    In this embodiment, the control valve comprises at least one essentially hollow cylindrical valve housing and one control piston arranged so that it can move axially in this housing. The control piston can be shifted and held in any position between two maximum values by an actuator, for example, an electromagnetic or hydraulic actuator. In this way, the actuator can be connected to the control valve or fixed in position relative to this valve. 
         [0017]    An inflow port and at least one outflow port are formed on the valve housing. Pressure medium is led into the hollow space within the valve housing via the inflow port. Pressure medium can flow out from the interior of the valve housing via the outflow port. In addition, several, at least two supply ports are formed that communicate via supply lines with one or several loads, for example, a device for the variable adjustment of control times of gas-exchange valves of an internal combustion engine. 
         [0018]    The ports can be constructed, for example, as grooves that are formed on an outer lateral surface of the valve housing and communicate with the interior of the valve housing via radial openings. Alternatively, the radial openings can also be used as ports. It is also conceivable to use an axial opening of the valve housing as a port, for example, as an inflow or outflow port. 
         [0019]    For controlling the pressure medium flows, control elements are formed on the control piston or the valve housing and counter control elements are formed on the other component. These interact such that the various supply ports cannot communicate with the interior of the valve housing or with pressure medium-guiding or pressure-less regions of the interior of the valve housing as a function of the position of the control piston relative to the valve housing. Here, for controlling the first supply port there are first control elements and for controlling the second supply port there are second control elements. Advantageously, the regions in which the first and the second control elements are formed, respectively, at least partially overlap in the axial direction, through which the axial installation-space requirements for given control logic can be minimized. 
         [0020]    To be able to shape the pressure medium flows to the various supply ports differently for one or more axial positions of the control piston relative to the valve housing, it can be provided that the first region extends in the peripheral direction of the control valve within a first angular region and that the second region extends in the peripheral direction of the control valve within a second angular region, wherein the regions do not overlap in the peripheral direction. 
         [0021]    In this way it is achieved that the pressure medium flows to the various supply ports do not flow offset axially relative to each other, in contrast to the state of the art, but instead parallel to each other in sectors of the control valve separated from each other in the peripheral direction. Instead of a series arrangement, there is an installation space-saving parallel arrangement. 
         [0022]    An additional advantage of this sectorization of the pressure medium flows is that more complex control logics can also be represented, even without the need for additional installation space. This advantage is realized primarily when there are more than two supply ports. For example, in cases with three supply ports, for one of the supply ports the control elements can be formed in the entire axial region that the two other supply ports take up. The number of control elements can be increased without the need for more installation space, by which more complex switching logic can also be represented. 
         [0023]    In one realization of the invention, it is provided to form the control elements on the valve housing. In this way it can be provided that the control elements are formed on an internal lateral surface of the valve housing. 
         [0024]    Thus, the control piston can also be used in applications in which the control piston rotates relative to the valve housing. This is the case, for example, in applications in which the actuator is not locked in rotation with the control valve and the control valve is arranged within a central borehole of a rotating component, for example, an inner rotor of a camshaft adjuster. 
         [0025]    In one advantageous refinement of the invention, it is provided that the first control elements interact with the counter control elements such that only one pressure medium flow between the first supply port and the interior of the valve housing is controlled as a function of the axial position of the components relative to each other. Likewise, it can be provided that the second control elements interact with the counter control elements such that only one pressure medium flow between the second supply port and the interior of the valve housing is controlled as a function of the axial position of the components relative to each other. 
         [0026]    In another construction of a hydraulic control valve with an essentially hollow cylindrical valve housing on which at least two supply ports, at least one inflow port, and at least one outflow port are formed, the objective is met according to the invention such that at least two of the ports are arranged at least partially overlapping in the axial direction of the valve housing. 
         [0027]    In one realization of the invention, it is provided that the supply ports are arranged at least partially overlapping in the axial direction of the valve housing. 
         [0028]    In an advantageous refinement of the invention, it is provided that the ports overlapping in the axial direction do not overlap in the peripheral direction of the valve housing. 
         [0029]    In one realization of the invention, it is provided that the ports overlapping in the axial direction are separated from each other hydraulically in the peripheral direction of the valve housing by blocking elements. 
         [0030]    In this way it can be provided to form the blocking elements integrally with the valve housing. Through the partial overlapping of the ports in the axial direction, the need for axial installation space of the control valve can be reduced to a minimum. The ports, in addition to the supply ports also the inflow and/or outflow ports, can be packed more tightly in the axial direction, by which the control valve can also be used in more compact surrounding constructions or loads. 
         [0031]    In another construction of a hydraulic control valve with an essentially hollow cylindrical valve housing and an essentially hollow cylindrical control piston that can move axially in this housing, wherein at least one inflow port (P) and at least two supply ports are formed on the valve housing, wherein pressure medium can be fed via the inflow port to the interior of the valve housing, the objective according to the invention is met in that pressure medium can be fed to the first supply port via a pressure medium line that is formed between an outer lateral surface of the control piston and an inner lateral surface of the valve housing. In this way, it can be provided to form the control piston integrally. Alternatively, the control piston can be made from several separate components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]    Additional features of the invention emerge from the following description and from the drawings in which embodiments of the invention are shown simplified. Shown are: 
           [0033]      FIG. 1  an embodiment according to the invention of a control valve in perspective view, 
           [0034]      FIG. 2  a partial longitudinal section view through the control valve according to  FIG. 1 , 
           [0035]      FIG. 3   a  a longitudinal section view through a section of the control valve according to  FIG. 2 , 
           [0036]      FIG. 3   b  a cross-sectional view through the control valve according to  FIG. 3   a  along the line B-B, 
           [0037]      FIG. 3   c  a cross-sectional view through the control valve according to  FIG. 3   a  along the line C-C, 
           [0038]      FIG. 4  a cross-sectional view through a camshaft adjuster including an attached hydraulic circuit, 
           [0039]      FIG. 5  a control logic diagram realized by the control valve according to the invention according to  FIG. 2 , 
           [0040]      FIG. 6   a - 6   g  diagrams of the control valve according to  FIG. 3   a  in its various control positions, 
           [0041]      FIG. 7   a - 7   e  longitudinal section views through a section of another embodiment according to the invention of a control valve in its various control positions, 
           [0042]      FIG. 8   a  a cross-sectional view through the control valve according to  FIG. 7   a  along the line A-A, 
           [0043]      FIG. 8   b  a cross-section view through the control valve according to  FIG. 7   a  along the line B-B, 
           [0044]      FIG. 8   c  a cross-sectional view through the control valve according to  FIG. 7   a  along the line C-C. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0045]    In the following, the invention will be described with reference to a control valve  1  with three supply ports. Also conceivable would be embodiments with 2 or more than three supply ports. 
         [0046]      FIGS. 1 and 2  show a first embodiment of a control valve  1  according to the invention. This comprises an electromagnetic actuator  2 , a valve housing  3 , and a control piston  4 . The essentially hollow cylindrical control piston  4  is arranged so that it can move axially within the similarly essentially hollow cylindrical valve housing  3 . In this way, the outer diameter of the control piston  4  is essentially adapted to the inner diameter of the valve housing  3 . Through the use of a tappet rod  5 , a movement of a not-shown armature of the actuator  2  can be transferred to the control piston  4 , by which the control piston can be positioned in the axial direction against the force of a spring element  6 . On the valve housing  3 , three supply ports V 1 , V 2 , V 3 , one inflow port P, one radial outflow port T 1  and one axial outflow port T 2  are formed. The supply ports V 1 , V 2 , V 3 , the inflow port P, and the radial outflow port T 1  are formed as grooves extending in the peripheral direction in an outer lateral surface of the valve housing  3 . The second and third supply ports V 2 , V 3 , the inflow port P, and the radial outflow port T 1  are arranged offset axially relative to each other, while the first supply port V 1  extends in the axial direction along the entire length of the region taken up by the other supply ports V 2 , V 3 , and the inflow port P. The axial outflow port T 2  is formed as an axial opening of the valve housing  3 . 
         [0047]    The first supply port V 1  extends in the peripheral direction within a first angular range  7  and in the axial direction within a first region  7   a . The second and third supply ports V 2 , V 3  and the inflow port P extend in the peripheral direction within a second angular range  8 , wherein the second supply port V 2  extends in the axial direction within a second region  8   a . In this way, the angular regions  7 ,  8  are arranged not overlapping in the peripheral direction of the control valve  1  and are separated from each other hydraulically by blocking elements  9  ( FIGS. 3   a  to  3   c ). The first and the second regions  7   a ,  8   a  are advantageously arranged at least partially overlapping. In the illustrated embodiment, the second region  8   a  is covered completely by the first region  7   a.    
         [0048]    In addition, in the illustrated embodiment, a hollow cylindrical adapter sleeve  10  is provided that comprises the valve housing  3 . In this way, the outer diameter of the valve housing  3  is adapted essentially to the inner diameter of the adapter sleeve  10 . Using the adapter sleeve  10 , a connection can be established between the ports P, T 1 , T 2 , V 1 , V 2 , V 3 , and not-shown connection lines of a surrounding construction, for example, a receptacle in a cylinder head or cylinder head cover. For this purpose, on the outer lateral surface of the adapter sleeve  10  there are five grooves  11  running in the peripheral direction and arranged offset relative to each other axially. These grooves each communicate via radial sleeve openings  12  with one of the ports P, T 1 , V 1 , V 2 , V 3 . In this way, the sleeve openings  12  of each groove  11  are formed in the peripheral direction only in the angular region  7 ,  8  of the corresponding port P, T 1 , V 1 , V 2 , V 3 . The advantage of this embodiment with an adapter sleeve  10  lies in that during the installation of the control valve  1 , no defined installation orientation of the control valve  1  must be observed relative to the connection lines, because the pressure medium can reach each connection line via the grooves  11  in each position of the control valve  1 . Also conceivable, however, are embodiments of the control valve  1  without an adapter sleeve  10  in which the outer lateral surface of the control piston  4  comes to lie directly on the valve receptacle. In the following, the invention will be explained with reference to an embodiment that is shown in  FIGS. 3   a  to  3   c.    
         [0049]    In  FIG. 3   a , the part of the control valve  1  according to the invention is shown on which the inflow port P and the supply ports V 1 -V 3  are formed. In contrast to  FIG. 2 , here the control piston  4  is formed in one piece. On the valve housing  3  there are eight groups of radial housing openings  13 - 20 . The first to third housing openings  13 - 15  are formed exclusively in the first supply port V 1  and offset relative to each other axially. The fourth and fifth housing openings  16 ,  17  are formed exclusively in the second supply port V 2  and also offset axially relative to each other. The sixth housing openings  18  are formed exclusively in the third supply port V 3 . The seventh housing openings  19  are formed exclusively in the inflow port P. The eighth housing openings  20  are formed exclusively in the radial outflow port T 1 . Through use of the housing openings  13 - 20 , each port P, T 1 , V 1 , V 2 , V 3  can communicate with the interior of the valve housing  3 . 
         [0050]    On an outer lateral surface of the control piston  4  there are four annular grooves  21 - 24  that are spaced apart axially and that extend along the entire periphery of the control piston  4 . In addition, on the control piston  4  there are two groups of radial piston openings  25 ,  26 . The first piston openings  25  are formed in the groove base of the first annular groove  21  and the second piston openings  26  are formed in the groove base of the third annular groove  23 . Through use of the piston openings  25 ,  26 , each annular groove  21 ,  23  communicates with the interior of the control piston  4 . 
         [0051]    Pressure medium can be fed to the interior of the valve housing  3  via the inflow port P. Pressure medium flows can be established within the control valve  1  between various ports P, T 1 , T 2 , V 1 , V 2 , V 3  by control elements and counter control elements. 
         [0052]    For this purpose, first to fourth control elements  27 - 30  ( FIG. 6   a ) are formed on an inner lateral surface of the valve housing  3  and counter control elements  31  ( FIG. 6   b ) are formed on an outer lateral surface of the control piston  4 . 
         [0053]    The first control elements  27  comprise four control edges  32 - 35 , wherein the first and the second control edges  32 ,  33  are defined by the regions of the boundary walls of the first and third housing openings  13 ,  15  spaced farthest apart from each other in the axial direction. 
         [0054]    The third and fourth control edges  34 ,  35  are defined by the regions of the boundary wall of the second housing opening  14  spaced farthest apart from each other in the axial direction. 
         [0055]    The second control elements  28  comprise a fifth and a sixth control edge  36 ,  37 , wherein these are defined by the regions of the boundary walls of the fourth and fifth housing openings  16 ,  17  spaced farthest apart from each other in the axial direction. 
         [0056]    The third control elements  29  comprise a seventh and an eighth control edge  38 ,  39 , wherein these are defined by the regions of the boundary wall of the sixth housing opening  18  spaced farthest apart from each other in the axial direction. 
         [0057]    The fourth control elements  30  comprise a ninth control edge  40 , wherein this is defined by the region of the boundary wall of the seventh housing opening  19  lying closest to the fifth housing opening  17  in the axial direction. 
         [0058]    The counter control elements  31  comprise seventh counter control edges  41 - 47 , wherein the first counter control edge  41  is defined by the axial boundary wall of the fourth annular groove  24 , the second counter control edge  42  is defined by the spring element-side end of the control piston  4 , the third and fourth counter control edges  43 ,  44  are defined by the axial boundary walls of the third annular groove  23 , the fifth and the sixth counter control edges  45 ,  46  are defined by the axial boundary walls of the second annular groove  22 , and the seventh counter control edge  47  is defined by the axial boundary wall of the first annular groove  21  facing away from the second annular groove  22 . 
         [0059]    The first control elements  27  are formed exclusively in the first angular region  7 . The second to fourth control elements  28 - 30  are formed exclusively in the second angular region  8 . The counter control elements  31  extend along the entire periphery of the control piston  4 . 
         [0060]    In this embodiment, the control elements  27 - 30  are formed on an inner lateral surface of the valve housing  3  and the counter control elements  31  are formed on the outer lateral surface of the control piston  4 . Also conceivable, however, are alternative solutions with an exactly opposite configuration. 
         [0061]    With reference to the example of a camshaft adjuster  48  shown in  FIG. 4 , in the following the function of the control valve  1  will be explained. 
         [0062]    The camshaft adjuster  48  has an outer rotor  49 , an inner rotor  50 , and two not-shown side covers. The outer rotor  49  is in drive connection with a not-shown crankshaft, for example, by a traction mechanism drive. The inner rotor  50  is constructed in the form of an impeller wheel and is locked in rotation with a similarly not-shown camshaft. Starting from an outer peripheral wall of the outer rotor  49 , several projections extend radially inward, by which the outer rotor  49  is supported on the inner rotor so that it can rotate relative to the inner rotor  50 . Each of the side covers is arranged on one of the axial side surfaces of the outer rotor  49  and fixed on the rotor locked in rotation. Within the camshaft adjuster  48 , there is a pressure space  51  between every two projections adjacent in the peripheral direction. This pressure space is bounded in the peripheral direction by opposing, essentially radially extending boundary walls of adjacent projections, in the axial direction by the side covers, radially inward by the inner rotor  50 , and radially outward by the outer rotor  49 . A vane  52  of the inner rotor  50  projects into each of the pressure spaces  51 . Each vane  52  divides each pressure space  51  into two oppositely acting pressure chambers  53 ,  54 . 
         [0063]    By pressurizing one group of pressure chambers  53 ,  54  and depressurizing the other group, the phase position of the outer rotor  49  relative to the inner rotor  50  can be varied. By pressurizing both groups of pressure chambers  53 ,  54 , the phase position of the two rotors  49 ,  50  can be held constant relative to each other. Alternatively, it can be provided to pressurize none of the pressure chambers  53 ,  54  with pressure medium during phases of constant phase position. 
         [0064]    In addition, a locking mechanism  55  is provided with which a mechanical connection between the two rotors  49 ,  50  can be established. The locking mechanism  55  comprises an axially displaceable locking pin  56  that is arranged in a receptacle of the inner rotor  50 . The locking pin  56  is loaded by means of a not-shown spring with a force in the direction of one of the side covers in which a not-shown locking connecting rod is formed. If the inner rotor  50  is located in a defined phase position (locking position) relative to the outer rotor  49 , then the locking pin  56  can engage in the connecting rod and thus a mechanical, rotationally locked connection between the two rotors  49 ,  50  can be established. 
         [0065]    To change the locking mechanism  55  from the unlocked into the locked state, it is provided that the connecting rod is pressurized with pressure medium. Therefore, the locking pin  56  is forced back against the force of the spring into the receptacle and thus the mechanical lock is cancelled. 
         [0066]    For feeding pressure medium to the pressure chambers or discharging pressure medium from the pressure chambers  53 ,  54  and the connecting rod, the control valve  1  is provided. The first supply port V 1  communicates with the connecting rod of the locking mechanism  55 . The second supply port V 2  communicates with the first pressure chambers  53 . The third supply port V 3  communicates with the second pressure chambers  54 . The inflow port P communicates with a not-shown pressure medium source and the outflow ports T 1 , T 2  with a similarly not-shown tank. 
         [0067]    For the operation of the camshaft adjuster  48 , the control logic shown in  FIG. 5  has proven advantageous. As a function of the excitation of the actuator  2  or a displacement path D of the control piston  4  relative to the valve housing  3 , in this case the control valve  1  runs though seven control positions S 1 -S 7 . In a first control position S 1 , the first and the third supply port V 1 , V 3  are connected to one of the outflow ports T 1 , T 2 , while the second supply port V 2  is connected neither to an outflow port T 1 , T 2  nor to the inflow port P. When transitioning into the second control position S 2 , the first supply port V 1  is separated from the outflow ports T 1 , T 2  and connected to the inflow port P that also communicates with the second supply port V 2  when transitioning to the third control position S 3 . When transitioning into the fourth control position S 4 , the third supply port V 3  is separated both from the outflow ports T 1 , T 2  and also from the inflow port P, while in the fifth control position S 5 , none of the supply ports V 1 -V 3  communicates with the outflow ports T 1 , T 2  or the inflow port P. When transitioning to the sixth control position S 6 , the third supply port V 3  is connected to the inflow port P. When transitioning into the seventh control position S 7 , the first and the second supply port V 1 , V 2  are connected to one of the outflow ports T 1 , T 2 . 
         [0068]    The different control positions S 1 -S 7  of the control valve  1  are shown in  FIGS. 6   a - 6   g . In contrast to the embodiment shown in  FIG. 3   a , the inflow port P and the third supply port V 3  are each realized as housing openings  18 ,  19 . Furthermore, the first and the second supply ports V 1 , V 2  are formed as axially extending grooves. The second piston openings  26  are here indicated by two perpendicular lines. The axial displacement path of the control piston  4  relative to the valve housing  3  is designated with D, wherein the configuration shown in  FIG. 6   a  corresponds to a displacement path D=0. Here, the control piston  4  assumes one of the maximum end positions. 
         [0069]    Pressure medium can be fed via the inflow port P to the control valve  1 . This pressure medium is led via the seventh housing openings  19  into the interior of the valve housing  3 . Thus, in every control position S 1 -S 7 , pressure medium is led into the first annular groove  21 , via the first piston opening  25  into the interior of the control piston  4 , and via the second piston openings  26  into the third annular groove  23 . In the third to seventh control piston S 3 -S 7 , pressure medium is also led into the second annular groove  22 . 
         [0070]    In  FIG. 6   a , control valve  1  is shown in the first control position S 1 . In this control position S 1 , the first, the second, the fourth housing openings  13 ,  14 ,  16  and the connection between the seventh housing opening  19  and the second annular groove  22  are blocked by the control piston  4 , while the second or the eighth control edge  33 ,  39  in connection with the second counter control edge  42  releases a connection between the first or the third supply port V 1 , V 3  and the axial outflow port T 2 . Thus, pressure medium is led from the first and the third supply port V 1 , V 3  to the axial outflow port T 2  and furthermore into a not-shown tank. Simultaneously, the second supply port V 2  communicates neither with one of the outflow ports T 1 , T 2  nor with the inflow port P. 
         [0071]    In  FIG. 6   b , the control valve  1  is shown in the second control position S 2 . In this control position S 2 , the first, the third, the fourth housing openings  13 ,  15 ,  16  and the connection between the seventh housing opening  19  and the second annular groove  22  are blocked by the control piston  4 , while the eighth control edge  39  in connection with the second counter control edge  42  releases a connection between the third supply port V 3  and the axial outflow port T 2 . Simultaneously, the third control edge  34  in connection with the fourth counter control edge  44  enables a connection between the second housing opening  14  and the third annular groove  23 . Thus, pressure medium is led from the third supply port V 3  to the axial outflow port T 2  and from the interior of the control piston  4  to the first supply port V 1 . Simultaneously, the second supply port V 2  communicates neither with one of the outflow ports T 1 , T 2  nor with the inflow port P. 
         [0072]    When transitioning to the third control piston S 3  shown in  FIG. 6   c  of the control valve  1 , the ninth control edge  40  in connection with the sixth counter control edge  46  releases a connection between the inflow port P and the second annular groove  22 , by which pressure medium between the sixth control edge  37  and the fifth counter control edge  45  is led to the second supply port V 2 . 
         [0073]    When transitioning to the fourth control position S 4  of the control valve  1  shown in  FIG. 6   d , the sixth housing opening  18  is blocked by the control piston  4 , by which the third supply port V 3  communicates neither with one of the outflow ports T 1 , T 2  nor with the inflow port P. 
         [0074]    Another displacement D of the control piston  4  causes the transition to the fifth control position S 5  of the control valve  1  shown in  FIG. 6   e . Here, the second and the fifth housing opening  14 ,  17  are blocked by the control piston  4 . Thus, the supply ports V 1 , V 2 , V 3  communicate neither with one of the outflow ports T 1 , T 2  nor with the inflow port P. 
         [0075]    Another displacement D of the control piston  4  causes the transition to the sixth control position S 6  of the control valve  1  shown in  FIG. 6   f . Here, the seventh control edge  38  in connection with the seventh counter control edge  47  releases a connection between the third supply port V 3  and the first annular groove  21 , by which pressure medium is led from the inflow port P to the third supply port V 3 . 
         [0076]    Another displacement D of the control piston  4  causes the transition to the seventh control position S 7  of the control valve  1  shown in  FIG. 6   g . Here, the first or the fifth control edge  32 ,  36  in connection with the first counter control edge  41  releases a connection between the first or second supply port V 1 , V 2  and the fourth annular groove  24 , by which pressure medium is led from the first and second supply port V 1 , V 2  to the radial outflow port T 1 . 
         [0077]    In this embodiment, the pressure medium flow is led to the first supply port V 1 , within the control piston  4 , parallel to the pressure medium flows to the other supply ports V 2 , V 3 , into the first and second annular groove  21 ,  22 . Both the interior of the control piston  4  and also the first and second annular groove  21 ,  22  are used as pressure medium lines. Instead of a series arrangement of ports, a parallel arrangement can be selected, wherein one of the pressure medium lines can supply pressure medium to the first supply port V 1  and the other pressure medium lines can supply pressure medium to the second and third supply ports V 2 , V 3 . Therefore, the need for installation space for the control valve  1  can be reduced significantly. 
         [0078]    In addition, in contrast to the embodiment in the state of the art, only one inflow port P is required, by which the need for axial installation space is further reduced. Through the arrangement of the ports P, V 1 , V 2 , V 3  in axially overlapping regions, there is more space for forming the control elements  27 - 30  having a smaller need for installation space. In this way, more complex control logic can also be realized. Because the first control elements  27  can be formed independent of and along the entire region of the second to fourth control elements  28 - 30 , through slight modifications on the valve housing  3 , a plurality of conceivable control logic can be realized. 
         [0079]      FIG. 7   a  shows another embodiment of a control valve  1  according to the invention. Analogous to the diagram  3   a  of the first embodiment, only the valve housing  3  and the control piston  4  are shown in the region of the supply ports V 1 -V 3  and the inflow port P. The essentially hollow cylindrical control piston  4  can move axially within the similarly essentially hollow cylindrical valve housing  3 . In this way, the outer diameter of the control piston  4  is essentially adapted to the inner diameter of the valve housing  3 . Through the use of a not-shown tappet rod, a movement of a not-shown armature of the actuator  2  can be transferred to the control piston  4 , by which this can be positioned in the axial direction against the force of a not-shown spring element. On the valve housing  3 , three supply ports V 1 , V 2 , V 3 , one inflow port P, and one axial outflow port T 2  are formed. In addition, analogous to  FIG. 2 , another radial outflow port T 1  can be formed. 
         [0080]    The supply ports V 1 , V 2 , V 3  and the inflow port P are formed as grooves in an outer lateral surface of the valve housing  3 , wherein these grooves extend in the peripheral direction. The third supply port V 3  and the inflow port P are offset axially relative to each other and offset axially relative to the first and second supply ports V 1 , V 2 , while the first and the second supply ports V 1 , V 2  are arranged overlapping in the axial direction. 
         [0081]    The first supply port V 1  extends in the peripheral direction within a first angular region  7 , while the second supply port V 2  extends in the peripheral direction within a second angular region  8 . In this way, the angular regions  7 ,  8  do not overlap in the peripheral direction of the control valve  1  ( FIGS. 8   a - 8   c ). The third supply port V 3  and the inflow port P extend along the entire periphery of the valve housing  3 . 
         [0082]    Just as in the first embodiment, the use of an adapter sleeve  10  is conceivable that establishes a connection between the control valve  1  and a surrounding construction. 
         [0083]    On the valve housing  3  there are five groups of radial housing openings  13 - 17 . The first and second housing openings  13 - 14  are formed exclusively in the first supply port V 1  and offset axially relative to each other. The third housing openings  15  are formed exclusively in the second supply port V 2 . The fourth housing openings  16  are formed exclusively in the third supply port V 3 . The fifth housing openings  17  are formed exclusively in the inflow port P. Using the housing openings  13 - 17 , each port P, V 1 , V 2 , V 3  can communicate with the interior of the valve housing  3 . 
         [0084]    In addition, on an inner lateral surface of the valve housing  3  there are four housing grooves  57 - 60  offset axially relative to each other and four annular grooves  21 - 24  spaced apart on an outer lateral surface of the control piston  4 . The annular and the housing grooves  21 - 24 ,  57 - 60  extend along the entire periphery of the control piston  4  or the valve housing  3 , wherein the second annular groove  22  can also be formed only within the second angular region  8  or as an axial groove within the second angular region  8 . In addition, on the control piston  4  there are radial piston openings  25  by which the four housing grooves  60  communicate with the interior of the control piston  4 . 
         [0085]    Pressure medium can be fed to the interior of the valve housing  3  via the inflow port P. Through the use of control elements and counter control elements, pressure medium flows can be established within the control valve  1  between various ports P, T 1 , T 2 , V 1 , V 2 , V 3 . For this purpose, first to fourth control elements  27 - 30  are formed on an inner lateral surface of the valve housing  3  and counter control elements  31  are formed on an outer lateral surface of the control piston  4 . 
         [0086]    The first control elements  27  comprise three control edges  32 - 34 , wherein the first and the second control edge  32 ,  33  are defined by the regions of the boundary walls of the first and second housing openings  13 ,  14  spaced farthest apart from each other in the axial direction. The third control edge  34  is defined by the axial boundary wall of the first housing groove  57 . 
         [0087]    The second control elements  28  comprise the third and a fourth control edge  34 ,  35 , wherein the fourth control edge  35  is defined by the regions of the boundary walls of the third housing openings  15  facing the inflow port P. 
         [0088]    The third control elements  29  comprise a fifth and a sixth control edge  36 ,  37 . The fifth control edge  36  is defined by the axial boundary wall of the fourth housing groove  60  and the sixth control edge  37  is defined by the regions of the boundary walls of the fifth housing openings  17  facing the third supply port V 3 . 
         [0089]    The fourth control elements  30  comprise a seventh control edge  38 , wherein this is defined by the regions of the boundary walls of the fifth housing openings  17  axially opposite the sixth control edges  37 . 
         [0090]    The counter control elements  31  comprise six counter control edges  41 - 46 , wherein the first counter control edge  41  is defined by the spring element-side end of the control piston  4 , the second counter control edge  42  is defined by the spring element-side, axial boundary wall of the first annular groove  21 , the third counter control edge  43  is defined by the spring element-side, axial boundary wall of the second annular groove  22 , the fourth counter control edge  44  is defined by the axial boundary wall of the third annular groove  23  facing away from the spring element  6 , and the fifth and sixth counter control edges  45 ,  46  are defined by the axial boundary walls of the fourth annular groove  23 . 
         [0091]    The first and the second control edges  32 ,  33  are formed exclusively in the first angular region  7 . The fourth control edge  35  is formed exclusively in the second angular region  8 . The third and fifth to seventh control edges  34 ,  36 - 38  are formed along the entire inner periphery of the valve housing  3 . The counter control elements  31  extend along the entire periphery of the control piston  4 . 
         [0092]    The control logic realized in this embodiment of a control valve  1  corresponds to that shown in  FIG. 5  with the exception that, in the fifth control position S 5 , all of the supply ports V 1 -V 3  communicate with the inflow port P. 
         [0093]    The different control positions S 1 -S 7  of the control valve  1  are shown in  FIGS. 7   a - 7   e . In contrast to the embodiment shown in  FIG. 7   a , in  FIGS. 7   b - 7   e , the second supply port V 2  is realized by the third housing openings  15 . 
         [0094]    Pressure medium can be fed to the control valve  1  via the inflow port P. This pressure medium is led via the fifth housing openings  17  into the interior of the valve housing  3 . In the first to fifth control position S 1 -S 5 , pressure medium is thus led into the third annular groove  23 . In the second to fifth control positions S 2 -S 5 , pressure medium is also led from the third annular groove  23  via the third housing groove  59  into the second annular groove  22 . In the fifth to seventh control positions S 5 -S 7 , the pressure medium supplied from the inflow port P is led into the fourth annular groove  24 . 
         [0095]    In  FIG. 7   a , control valve  1  is shown in the first control position S 1 . In this control position S 1 , pressure medium is led via the fifth housing opening  17  exclusively into the third annular groove  23 , while a pressure medium flow into the second or fourth annular groove  22 ,  24  is blocked by the control piston  4 . In addition, the first housing opening  13  is also blocked by the control piston  4 . Thus, none of the supply ports V 1 -V 3  communicates with the inflow port P. The first control edge  32  in connection with the first counter control edge  41  releases a connection between the second housing opening  14  and the first housing groove  57 . Thus, pressure medium can flow from the first supply port V 1  to the axial outflow port T 2 . In addition, the fifth control edge  36  in connection with the sixth counter control edge  46  releases a connection between the fourth housing opening  16  and the fourth housing groove  60 . Pressure medium can thus flow from the third supply port V 3  to an optional radial outflow port T 1  or via the first piston openings  25  to the axial outflow port T 2 . Simultaneously, a connection between the second supply port V 2  and the axial outflow port T 2  is blocked by the control piston  4 , by which this communicates with neither an outflow port T 1 , T 2  nor the inflow port P. 
         [0096]    When transitioning to the second control position S 2  of the control valve  1  shown in  FIG. 7   b , the control piston  4  releases a connection between the third and the second annular groove  23 ,  22  via the third housing groove  59 . Simultaneously, the second control edge  33  in connection with the third counter control edge  43  releases a connection between the second annular groove  22  and the first housing opening  13 . In addition, the control piston  4  blocks the connection between the second housing opening  14  and the first housing groove  57 . Thus, pressure medium is led from the inflow port P to the first supply port V 1 , wherein it is also simultaneously blocked from flowing to the axial outflow port T 2 . Simultaneously, the control piston  4  blocks a connection between the first supply port V 1  and the second housing groove  58 . 
         [0097]    When transitioning to the third control position S 3  of the control valve  1  shown in  FIG. 7   c , the fourth control edge  35  in connection with the third counter control edge  43  releases a connection between the third housing opening  15  and the second annular groove  22 , by which pressure medium is led from the inflow port P to the second supply port V 2 . 
         [0098]    Upon further displacement D of the control piston  4  into the fourth control position S 4 , initially the fifth control edge  36  in connection with the sixth counter control edge  46  closes the connection between the fourth housing opening  16  and the fourth housing groove  60 , by which the third supply port V 3  communicates neither with one of the outflow ports T 1 , T 2  nor with the inflow port P. 
         [0099]    Upon further displacement D of the control piston  4 , the control valve  1  transitions into the fifth control position S 5  shown in  FIG. 7   d . In this way, the sixth control edge  37  in connection with the fifth counter control edge  45  releases a connection between the fifth housing opening  17  and the fourth annular groove  24 , by which pressure medium is led from the inflow port P to the third supply port V 3 . 
         [0100]    Further displacement D of the control piston  4  into the sixth control position S 6  has the effect that the connection between the fifth housing opening  17  and the third annular groove  23  is blocked by the seventh control edge  38  in connection with the fourth counter control edge  44 . Thus, the first and the second supply port V 2  are connected neither to one of the outflow ports T 1 , T 2  nor to the inflow port P. 
         [0101]    When transitioning to the seventh control position S 7  of the control valve  1  shown in  FIG. 7   e , the third control edge  34  in connection with the second counter control edge  42  releases a connection between the second or third housing opening  14 ,  15  and the first housing groove  57 . Pressure medium can be led from the first or second supply port V 1 , V 2  via the second or third housing opening  14 ,  15  and the first annular groove  21  to the axial outflow port T 2 . 
       REFERENCE SYMBOLS 
       [0000]    
       
           1  Control valve 
           2  Actuator 
           3  Valve housing 
           4  Control piston 
           5  Tappet rod 
           6  Spring element 
           7  First angular region 
           7   a  First region 
           8  Second angular region 
           8   a  Second region 
           9  Blocking element 
           10  Adapter sleeve 
           11  Groove 
           12  Sleeve opening 
           14  First housing opening 
           15  Third housing opening 
           16  Fourth housing opening 
           17  Fifth housing opening 
           18  Sixth housing opening 
           19  Seventh housing opening 
           20  Eighth housing opening 
           21  First annular groove 
           22  Second annular groove 
           23  Third annular groove 
           24  Fourth annular groove 
           25  First piston opening 
           26  Second piston opening 
           27  First control element 
           28  Second control element 
           29  Third control element 
           30  Fourth control element 
           31  Counter control element 
           32  First control edge 
           33  Second control edge 
           34  Third control edge 
           35  Fourth control edge 
           36  Fifth control edge 
           37  Sixth control edge 
           38  Seventh control edge 
           39  Eighth control edge 
           40  Ninth control edge 
           41  First counter control edge 
           42  Second counter control edge 
           43  Third counter control edge 
           44  Fourth counter control edge 
           45  Fifth counter control edge 
           46  Sixth counter control edge 
           47  Seventh counter control edge 
           48  Camshaft adjuster 
           49  Outer rotor 
           50  Inner rotor 
           51  Pressure space 
           52  Vane 
           53  First pressure chamber 
           54  Second pressure chamber 
           55  Locking mechanism 
           56  Locking pin 
           57  First housing groove 
           58  Second housing groove 
           59  Third housing groove 
           60  Fourth housing groove 
         D Displacement path 
         P Inflow port 
         T 1  Radial outflow port 
         T 2  Axial outflow port 
         V 1  First supply port 
         V 2  Second supply port 
         V 3  Third supply port