Directional control valve with electromagnetically actuated detent

Abstract

Directional control valve (10; 10') with a housing (20) in which a valve spool (30) is movably received in the direction of a longitudinal axis (11), wherein at least one first detent element (52) is provided which is movable transversely to the longitudinal axis (11), wherein it is positively engaged relative to the housing (20) in the direction of the longitudinal axis (11), wherein at least one first detent contour (53) is fixedly connected to the valve spool (30) in the direction of the longitudinal axis (11), wherein each first detent contour (53) can be brought into engagement with the at least one first detent element (52) such that the valve spool (30) is held in a corresponding first detent position (50), wherein an electromagnetic actuating device (70) is provided which is coupled to the at least one first detent element (52), characterized in that an actuating element (80) movable in the direction of the longitudinal axis (11) is provided.which has a wedge surface (81) inclined to the longitudinal axis (11), which is coupled to the at least one first detent element (52) in a movement-coupled manner, wherein the actuating body (80) is coupled to the actuating device (70) in such a way that an engagement already carried out between the at least one first detent element (52) and a first detent contour (53) can be released using the actuating device (70).

Description

[0001] The invention relates to a directional control valve according to the preamble of claim 1.

[0002] From DE 39 23 743 A1, a directional control valve is known which is intended for use in an agricultural tractor and which is equipped with a detent device. The detent device comprises first detent elements which are received in the valve spool, wherein the associated first detent contour is fixedly arranged on the housing of the directional control valve.

[0003] From DE 10 2012 208 943 A1, a directional control valve with a detent device is known, which is electromagnetically actuated. The first detent element is arranged on the housing, with the first detent contour being arranged on the valve spool. This detent device requires a considerable amount of space.

[0004] From EP 0 751 302 B1, a directional control valve with a detent device, which is electro-hydraulically actuated, is known. This detent device is complex.

[0005] From DE 31 05 203 A1, a hydraulic directional control valve with a mechanical detent device is known. The detent device implements a so-called kick-out function purely hydraulically.

[0006] From DE 10 2010 039 711 A1, a hydraulic valve with a detent device is known. An electrical solenoid coil arrangement acts on a detent shaft via a movably mounted, magnetizable ring core arrangement. This allows a force comparable to that of a hand lever to be exerted on the detent shaft, whereby in particular the non-locking detent can be overridden.

[0007] Another valve with a detent device is known from US 3 994 473 A.

[0008] The object of the present invention is to design the locking device in a simple and space-saving manner. Furthermore, the directional control valve according to the invention can be used as a replacement for the directional control valve known from DE 39 23 743 A1, which is intended for use in an agricultural tractor. A kick-out function can also be easily implemented, requiring only a few mechanical components in addition to suitable programming of the control device. If the kick-out function is not required, the aforementioned mechanical components can easily be omitted.

[0009] To solve the aforementioned problem, it is proposed according to claim 1 that an actuating body movable in the direction of the longitudinal axis is provided, which has a wedge surface inclined to the longitudinal axis, which is coupled to the at least one first detent body in terms of movement, wherein the actuating body is coupled to the actuating device in such a way that an engagement already carried out between the at least one first detent body and a first detent contour can be released using the actuating device.

[0010] The at least one first detent element is preferably a sphere. The at least one first detent contour is preferably rotationally symmetrical with respect to the longitudinal axis. Preferably, several first detent elements, most preferably three, are provided, which are arranged evenly distributed around the circumference of the counter-detent contour. The engagement between the at least one first detent element and the at least one first detent contour can be designed such that it can be released by exceeding a predetermined actuating force acting on the valve slide in the direction of the longitudinal axis. The wedge surface is preferably rotationally symmetrical with respect to the longitudinal axis, and most preferably is designed as an internal cone. The longitudinal axis is preferably located at the center of the valve slide, and the valve slide is most preferably substantially rotationally symmetrical with respect to the longitudinal axis.The actuating element is preferably rotationally symmetrical with respect to its longitudinal axis. The actuating force of the electromagnetic actuator is preferably continuously adjustable, and most preferably substantially proportional to a control voltage or a control current. Preferably, the actuating device continuously applies an actuating force to the actuator, which is only briefly released to release a previously engaged detent.

[0011] The dependent claims specify advantageous further developments and improvements of the invention.

[0012] The actuating device may comprise a pole tube that is rigidly connected to the housing, with a coil arranged around and rigidly connected to the pole tube, and the at least one first detent element, the at least one first detent contour, and the actuating element arranged within the pole tube. This results in a particularly space-saving actuating device. Furthermore, the directional control valve can be sealed particularly easily against the escape of pressurized fluid. Preferably, the pole tube, apart from a flow interruption section, consists of a magnetically conductive material. Preferably, the pole tube at least partially defines an interior space of the directional control valve that is fluid-tight. The pole tube and the housing are preferably formed separately from each other to simplify their manufacture. However, it is conceivable to manufacture the pole tube and the housing as a single piece.The coil can be detachably or permanently connected to the pole tube.

[0013] It can be provided that an armature movable in the direction of the longitudinal axis is arranged within the pole tube, which is coupled to the actuating body in such a way that an engagement already established between the at least one first detent element and a first detent contour can be released by means of the actuating device. A magnetic force can be exerted on the armature by energizing the coil. The coupling between the armature and the actuating body can be established in a particularly simple manner. Preferably, the magnetic force is transmitted to the actuating body by positive engagement. The armature preferably consists of a magnetically conductive material.

[0014] The armature can be designed to be movable along its longitudinal axis relative to the valve spool and relative to the housing. Preferably, the armature is not coupled to the valve spool's movement, so that movement of the valve spool does not substantially affect the movement of the armature.

[0015] It can be provided that the valve spool extends into the pole tube, with the at least one first detent contour being arranged directly on the valve spool. This allows a defined relationship between the position of the first detent contours and the position of the respective control positions of the directional control valve to be established in a particularly simple manner. The valve spool is preferably formed in one piece. However, it is also conceivable that the valve spool comprises two parts which are rigidly connected to each other in the area of ​​the connection between the housing and the pole tube.

[0016] The armature can be arranged in a ring around the valve spool. This results in a particularly space-saving directional control valve. The armature is preferably rotationally symmetrical with respect to the longitudinal axis.

[0017] It can be provided that a flux interrupting element, made of a magnetically non-conductive material, is arranged between the valve spool and the armature. The valve spool is preferably made of steel, so that it is magnetically conductive. The flux interrupting element ensures, on the one hand, that the magnetic flux is concentrated in the pole tube and in the armature, thereby minimizing stray flux in the valve spool. Furthermore, it prevents the armature from adhering to the valve spool due to magnetic forces. The flux interrupting element is preferably tubular in design, surrounding the valve spool in a ring-like manner. The flux interrupting element is preferably rotationally symmetrical with respect to the longitudinal axis. The flux interrupting element is preferably separate from the armature and the actuating body. The flux interrupting element preferably extends over the entire length of the armature and, if desired, beyond.

[0018] The flux interruption element can be movable along the longitudinal axis and coupled to the armature's movement. The flux interruption element is preferably movable relative to both the housing and the valve spool. Preferably, the armature rests directly against the flux interruption element along the longitudinal axis. This allows the armature's magnetic force to be transmitted to the actuating element via the flux interruption element. Preferably, a small clearance is provided between the flux interruption element and the valve spool.

[0019] It can be provided that the at least one first detent element is received in a separate retaining part, which is held between the housing and the pole tube. This simplifies the manufacture of the directional control valve. In particular, the retaining opening for the at least one first detent element is easy to produce.

[0020] It may be provided that at least one second detent element is provided, which is movable transversely to the longitudinal axis and is positively locked relative to the housing or relative to the valve slide in the direction of the longitudinal axis. At least one second detent contour is fixedly connected to the valve slide or the housing in the direction of the longitudinal axis. Each second detent contour can be brought into engagement with the at least one second detent element such that the valve slide is held in a corresponding second detent position. There is no coupling between the actuating device and the at least one second detent element. This provides further detent positions whose detent function is independent of the state of the actuating device. Preferably, the second detent contours are fixedly connected to the housing.

[0021] It can be provided that at least one second detent contour is arranged directly on the retaining element. The at least one second detent element is preferably arranged in the valve spool. Such a directional control valve is easy to manufacture and particularly space-saving.

[0022] At least one position sensing device can be provided with which the relative position between the valve spool and the housing can be measured. Preferably, the position sensing device comprises a switching device, wherein a switching contour is provided for each first detent position, which is fixedly connected to the valve spool and with which the switching device can be actuated. The switching device can be a mechanical switch, a capacitive proximity switch, or an inductive proximity switch. However, it is also conceivable that the position sensing device continuously measures the movement of the valve spool.

[0023] A pressure sensor can be provided to measure the load pressure at the directional control valve. A control device is provided to which the actuating device and the pressure sensor are connected. The control device is configured to release any engagement already established between the at least one first detent element and a first detent contour using the actuating device when the aforementioned load pressure exceeds a predetermined value. This allows for the simple implementation of a kick-out function, in which the detent is automatically released when the actuator connected to the directional control valve moves against a stop or into an end position. The valve spool is then preferably moved by a return spring into a control position in which the actuator no longer moves.

[0024] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0025] The invention is explained in more detail below with reference to the accompanying drawings. They show: Fig. 1 a circuit diagram of a first embodiment of a directional control valve according to the invention; Fig. 2 a longitudinal section of the directional control valve according to Fig. 1; Fig. 3 a circuit diagram of a second embodiment of a directional control valve according to the invention; and Fig. 4 a longitudinal section of the directional control valve according to Fig. 3.

[0026] Fig. Figure 1 shows a circuit diagram of a first embodiment of a directional control valve 10 according to the invention. The directional control valve 10 is intended, for example, for use in a valve block of an agricultural tractor, where it is part of an open hydraulic circuit. Accordingly, pressure fluid is drawn from a tank 121 by a pump 120 and delivered under pressure to the directional control valve 10. The pressure fluid is preferably a liquid and most preferably hydraulic oil. An actuator (not shown), which is designed, for example, as a hydraulic cylinder, is connected to the first and second working ports 13; 14 of the directional control valve 10, and whose direction and speed of movement can be adjusted by the directional control valve 10. For this purpose, the directional control valve 10 has a total of four switching positions 31; 32; 33; 34.In the first switching position 31, the first and second working ports 13; 14 are blocked, so that the actuator is hydraulically clamped and immobile. The return springs 35 bias the directional control valve 10 into the first switching position 31. The pump 120, which preferably has an adjustable displacement volume, delivers against a closed slide valve. The connecting line 15 to the tank 121 is pressure-relieved. It should be noted that all tank symbols in . Fig. 1. Designate the same tank 121.

[0027] In the second switching position 32, the pump 120 delivers the pressure fluid to the first working port 13, with the pressure fluid flowing back from the actuator to the second working port 14 flowing into the tank 121. In the third switching position 33, the pump 120 delivers the pressure fluid to the second working port 14, with the pressure fluid flowing back from the actuator to the first working port 13 flowing into the tank 121. In both the second and third switching positions 32 and 33, the pressure fluid is routed from the pump 120 via an optional pressure compensator 124, then via an optional check valve 125, then via a continuously adjustable orifice plate 12, and then via a connecting line 15. The continuously adjustable orifice plate 12 is controlled by the valve slide (No. 30 in the diagram). Fig. 2) of the directional control valve 10, the free cross-section of which determines the speed of movement of the actuator connected to the directional control valve 10. The pressure differential at the orifice 12 is regulated to a predetermined value by means of the pressure compensator 124. The pressure compensator 124 is acted upon in the opening direction by the pressure in the connecting line 15 and by a pre-tensioned spring, and in the closing direction by the pressure between the orifice 12 and the pressure compensator 124. In the first embodiment, the pressure in the connecting line 15, which is equal to the load pressure at the actuator, is measured by means of a pressure sensor 122, which is connected to a control device 123. The check valve allows only a flow of volume from the pump 121 to the actuator.The fourth switching position 34 is a free-running position in which the first and second working ports 13; 14 are connected to the tank 121, so that the actuator can move freely.

[0028] The directional control valve 10 according to the first embodiment has two first detent positions 50 and a second detent position 60. The two first detent positions 50 are assigned to the second and third switching positions 32 and 33, respectively, with the valve spool detenting at a predetermined opening cross-section of the orifice 12, for example, at the maximum opening cross-section. The second detent position 60 is assigned to the fourth switching position 34. The first detent positions 50 can be unlocked using an electromagnetic actuating device 70, which is connected to the control device 123. The second detent position 60 can be unlocked by exceeding a predetermined actuating force on the valve spool. This actuating force can be applied manually, hydraulically, electrohydraulically, or electromagnetically.

[0029] Fig. Figure 2 shows a longitudinal section of the directional control valve 10. Fig. 1. The valve spool 30 is essentially rotationally symmetrical with respect to the longitudinal axis 11, and is movably mounted in a fluid-tight bore in the housing 20 in the direction of the longitudinal axis 11. The valve spool 30 is provided with fine control notches, which define the continuously adjustable orifice 12. The other fluidic connections controlled by the valve spool 30 can be freely selected according to the desired application of the directional control valve 10, so further explanation is not necessary.

[0030] A separate pole tube 73, made of a magnetically conductive material, for example steel, is screwed into the housing 20. The pole tube 73 is essentially rotationally symmetrical with respect to the longitudinal axis 11 and is open at both ends. The pole tube 73 has an annular flux interruption section 74 that surrounds the longitudinal axis 11 and can be made of a magnetically non-conductive material, for example copper. However, it is also conceivable that the pole tube 73 is so thin in the region of the flux interruption section 74 that the material of the pole tube 73 saturates at the magnetic field strengths occurring there during operation.

[0031] A separate retaining element 100 is clamped between the pole tube 73 and the housing 20, primarily serving to simplify the manufacture of the directional control valve 10. Furthermore, a material of lower hardness can be selected for the housing 20. It is also conceivable to form the retaining element 100 integrally with the housing 20 or with the pole tube 72. In the present case, a total of three first detent elements 52, designed as spheres, are accommodated in the retaining element 100 and arranged evenly distributed around the longitudinal axis 11. A circular retaining opening is provided in the retaining element 100 for each first detent element 52, which penetrates the retaining element 100 perpendicular to the longitudinal axis 11. The first detent elements 52 are thus positively locked relative to the housing 20 in the direction of the longitudinal axis 11, while remaining movable transversely to the longitudinal axis 11.

[0032] The valve slide 30 extends through the retaining element 100 in the direction of the longitudinal axis 11, where two first detent contours 53 are provided directly on the valve slide 30, which correspond to the two first detent positions. In this area, the valve slide 30 has a circular cylindrical outer circumferential surface with respect to the longitudinal axis 11, the first detent contours 53 each being designed as annular grooves circumferentially around the longitudinal axis 11. The cross-sectional shape of these grooves is, for example, trapezoidal, so that the first detent elements 52 can be lifted out of the first detent contours 53 by movement of the valve slide 30 in the direction of the longitudinal axis 11, provided that this movement is not obstructed by the actuating element 80.

[0033] The actuating element 80 is designed as a separate component, which in this case is rotationally symmetrical with respect to the longitudinal axis 11. It is movably mounted in the pole tube 73 in the direction of the longitudinal axis 11, and is movable both relative to the housing 20 and relative to the valve slide 30. The valve slide 30 extends through the actuating element 80 in the direction of the longitudinal axis 11. At the end facing the first detent elements 52, the actuating element 80 has a wedge-shaped surface 81 inclined to the longitudinal axis 11, which in this case is designed as an internal circular cone whose diameter increases towards the first detent elements 52. The actuating element 80 is pressed in the direction of the first detent elements 52 by an electromagnetic actuating device 70, so that these are in turn pressed against the valve slide 30 by the wedge-shaped surface 81.When the first detent elements 52 are engaged in one of the first detent contours 53, they can only be pushed out of the respective detent contour 63 against the force of the actuating device 70 by moving the valve slide 30 and overcoming a detent force. When the corresponding actuating force of the actuating device 70 is released, the valve slide 30 can be moved with slight resistance, even if the first detent elements 52 engage in a first detent contour 53. Then, the first detent elements 52 are pushed radially outward by movement of the valve slide 30, causing the actuating element 80 to move into position. Fig. 2 moved to the right.

[0034] In the embodiment according to Fig. 2. The electromagnetic force of the actuating device 70 acts directly on the actuating body 80. However, it is also conceivable that the actuating body 80 is pressed towards the first detent elements 52 by a pre-tensioned spring, with the electromagnetic force of the actuating device 70 opposing the spring force. The armature 72 is preferably clamped between the aforementioned spring and the actuating body 80.

[0035] The electromagnetic actuating device 70 comprises a coil 71, which is arranged externally around the pole tube 73 and is rigidly connected to it. The coil 71 can be designed as a separate component that is detachably connected to the pole tube 73. However, it is also conceivable that the coil 71 is permanently encapsulated with the pole tube 73. The coil 71 is surrounded by a coil housing 75, a pole disk 76, and the pole tube 73 such that the magnetic flux generated by the coil 71 is concentrated in these parts. These parts are made of magnetically conductive material. The previously mentioned flux interruption section 74 forces the magnetic flux from the pole tube 73 into the armature 72, which is also made of magnetically conductive material. The armature 72 is movably mounted in the pole tube 73 in the direction of the longitudinal axis 11, surrounding the valve slide 30 in an annular manner.The anchor 72 is preferably rotationally symmetrical with respect to the longitudinal axis 11. It should be noted that in . Fig. Figure 2 shows the two end positions of the armature 72. Above the longitudinal axis 11, the position of the armature 72 is shown that is present when the coil 71 is not energized. Below the longitudinal axis 11, the energized position of the armature 72 is shown. In this position, the air gap 77 between the armature 72 and the pole tube 73 is smallest, so that energizing the coil 71 exerts a force on the armature 72, which is directed towards the actuating element 80. The coil 71 is electrically connected to a terminal socket 78, which projects outwards through the coil housing 75.

[0036] A flux interrupting element 90, made of a non-magnetically conductive material, is arranged between the armature 72 and the valve spool 30. This element is intended to minimize the magnetic leakage flux propagating across the valve spool 30, which is made of ferromagnetic steel. It is understood that a valve spool 30 made of a completely non-magnetically conductive material would be optimal in this respect. However, considering the stresses occurring in a hydraulic valve, a steel valve spool 30 is still preferred.

[0037] The flux interrupting element 90 is designed in the form of a circular cylindrical tube, which is provided on its outer circumferential surface with an annular projection on which the armature 72 is positively supported in the direction of the longitudinal axis 11. Furthermore, the flux interrupting element 90 rests against the end face of the actuating element 80, so that the magnetic force of the armature 72 is transmitted via the flux interrupting element 90 to the actuating element 80.

[0038] The valve slide 30 extends through the pole tube 73 along its entire length, projecting from it. Outside the pole tube 73, the valve slide 30 is partially surrounded by a return spring 35, which in this case is a coil spring. The return spring 35 is tensioned between two separate spring retainers 36, which are supported in opposite directions along the longitudinal axis 11, both on the valve slide 30 and indirectly on the housing 20. In the first control position, which is set by the return spring 35, both supports are effective. In the other positions of the valve slide 30, only one of the two possible supports is effective on each spring retainer 36. The return spring 35 is surrounded by a separate spring housing 37, which is rigidly connected to the pole tube 73. The position of the spring housing 37 in the direction of the longitudinal axis 11 is minimally adjustable in order to adjust the return spring 35 without play.The first interior space, in which the return spring 35 is housed, is preferably ventilated to the environment. The second interior space, in which the armature 72 is housed and which is sealed against the first interior space, is preferably pressure-relieved towards the tank. It is understood that the actuating device can also be designed in other configurations: for example, a flat armature could be used instead of a diving armature.

[0039] Three secondary detent elements 62 are provided, which are received in the valve slide 30 and are movable transversely to the longitudinal axis 11. They are positively locked in the valve slide 30 in the direction of the longitudinal axis 11. The associated secondary detent contour 63 is located on the inside of the retaining element 100. This detent is intended to hold the valve slide 30 in the fourth control position. This detent is not influenced by the actuating device 70. Instead, a pre-tensioned detent spring 65 is received in the valve slide 30, the spring force of which is transmitted to the secondary detent element 62 via several spherical coupling elements 64. The corresponding detent can be released by applying a sufficiently large force to the valve slide 30 in the direction of the longitudinal axis 11.

[0040] Fig. Figure 3 shows a circuit diagram of a second embodiment of a directional control valve 10' according to the invention. The second embodiment is identical to the first embodiment except for the differences described below, so that reference is made to the explanations in section 3. Fig. 1 and Fig. 2 is referred to. This includes the following: Fig. 1 to 4 identical or corresponding parts are marked with the same reference numbers.

[0041] In the second embodiment, several simplifications were made, primarily for cost savings. Firstly, the second detent elements and all associated structural components were omitted, and an additional first detent contour 53' was introduced, which engages the valve spool 30 in the fourth control position 34. Furthermore, the pressure sensor was omitted. In the first embodiment, this sensor serves, among other things, to implement a kick-out function, in which the detent is released when the load pressure measured by the pressure sensor exceeds a predetermined value. The detent is released, for example, when the actuator moves against a fixed stop or into its end position. Consequently, the valve spool is moved by the return spring in the first control position, in which the actuator no longer moves.

[0042] In the second embodiment, the directional control valve 10' is provided with several switching contours 112, which can be used to actuate a switching element 111. The switching element 111 is in the electrically open state when the directional control valve 10' is in the second or third control position 32; 33. It is in the electrically closed state when the directional control valve 10' is in the first or fourth control position 31; 34. It is understood that the polarity of the switching element 111 can also be reversed. A position sensor can also be used instead of the switching element 111. The control device 123 can thus differentiate the detent behavior according to the current control position. It is possible that the detent in the second and third control positions is released after a predetermined time interval.In the fourth control position, the detent should be permanently effective, whereby the detent force should be set so low that the detent can be released by applying force to the valve slide in the direction of the longitudinal axis.

[0043] It should also be noted that the detent is preferably deactivated whenever the vehicle or system in which the directional control valve is installed is switched from a deactivated state to an active state. This is also referred to as a neutral safety device, which, for example, is found in some models of agricultural tractors for safety reasons.

[0044] Fig. Figure 4 shows a longitudinal section of the directional control valve 10' towards Fig.3. The switching element 111 is housed in a separate switching housing 113, which is attached to the pole tube 73 and surrounded by the spring housing 37. The switching element 111 is designed as a mechanical switch, with a switching tongue following the switching contour 112. The switching contour 112 is located directly on the valve slide 30 and is formed by two annular grooves surrounding the valve slide 30. These grooves are arranged such that the switching element 111 switches to the electrically closed state when the switching tongues are located within the grooves. When the switching tongues contact the circular cylindrical outer circumferential surface of the valve slide 30, the switching element 111 is in the electrically open state. It is understood that the polarity of the switching element 111 can also be reversed. The switching device 111 is electrically connected to a connection socket 114, which protrudes outwards through the spring housing 37.It should be noted that the switching device 111 is in the same switching state in the first and fourth control positions. However, no detent is activated in the first control position, as no corresponding first detent contour is provided. Reference sign 10-way valve (first embodiment) 10-way valve (second embodiment) 11 Longitudinal axis 12 continuously adjustable apertures 13 first work connection 14 second work connection 15 connecting line 20 cases 30 valve slides 31 first tax position 32 second control position 33 third tax position 34 fourth control position 35 Return spring 36 spring plates 37 Spring housings 50 first rest position 52 first detent body 53 first rest contour 53' additional first detent contour of the second embodiment 60 second detent position 62 second locking body 63 second rest contour 64 coupling bodies 65 Detent spring 70 Actuating device 71 coil 72 anchors 73 Polar tube 74 River interruption section 75 coil housings 76 Polarizing disc 77 air gap 78 Connection socket 80 actuators 81 Wedge surface 82 Holding hole 90 flow interruption bodies 100 retaining part 110 position detection devices 111 Switching devices 112 Switch contour 113 Switch housings 114 Connection socket 120 pump 121 Tank 122 Pressure sensor 123 Control device 124 Pressure scale 125 Check valve

Claims

[1] Directional control valve (10; 10') with a housing (20) in which a valve spool (30) is movably received in the direction of a longitudinal axis (11), wherein at least one first detent element (52) is provided which is movable transversely to the longitudinal axis (11), wherein it is positively locked relative to the housing (20) in the direction of the longitudinal axis (11), wherein at least one first detent contour (53) is fixedly connected to the valve spool (30) in the direction of the longitudinal axis (11), wherein each first detent contour (53) can be brought into engagement with the at least one first detent element (52) such that the valve spool (30) is held in a corresponding first detent position (50), wherein an electromagnetic actuating device (70) is provided which is coupled to the at least one first detent element (52), characterized by, that an actuating body (80) movable in the direction of the longitudinal axis (11) is provided, which has a wedge surface (81) inclined to the longitudinal axis (11), which is coupled to the at least one first detent body (52) in terms of movement, wherein the actuating body (80) is coupled to the actuating device (70) in such a way that an engagement already carried out between the at least one first detent body (52) and a first detent contour (53) can be released using the actuating device (70). [2] Directional control valve according to claim 1, wherein the actuating device (70) comprises a pole tube (73) which is fixedly connected to the housing (20), wherein a coil (71) is arranged around the pole tube (73) and is fixedly connected to it, wherein the at least one first detent element (52), the at least one first detent contour (53) and the actuating element (80) are arranged inside the pole tube (73). [3] Directional control valve according to claim 2, wherein an anchor (72) movable in the direction of the longitudinal axis (11) is arranged within the pole tube (73), which is coupled to the actuating body (80) in such a way that an engagement already carried out between the at least one first detent body (52) and a first detent contour (53) can be released by means of the actuating device (70). [4] Directional control valve according to claim 3, wherein the armature (72) is movable in the direction of the longitudinal axis (11) relative to the valve spool (30) and relative to the housing (20). [5] Directional control valve according to one of claims 2 to 4, wherein the valve slide (30) extends into the pole tube (73), wherein the at least one first detent contour (53) is arranged directly on the valve slide (30). [6] Directional control valve according to claim 5, insofar as it refers back to claim 3, wherein the armature (72) is arranged in a ring-like manner around the valve spool (30). [7] Directional control valve according to claim 6, wherein a flow interrupting element (90) is arranged between the valve spool (30) and the armature (72), which consists of a magnetically non-conductive material. [8] Directional control valve according to claim 7, wherein the flow interruption body (90) is movable in the direction of the longitudinal axis (11), wherein it is coupled to the armature (72) for movement. [9] Directional control valve according to one of claims 2 to 8, wherein the at least one first detent element (52) is received in a separate retaining part (100) which is held between the housing (20) and the pole tube (73). [10] Directional control valve according to one of the preceding claims, wherein at least one second detent element (62) is provided which is movable transversely to the longitudinal axis (11), wherein it is positively locked relative to the housing (20) or relative to the valve spool (30) in the direction of the longitudinal axis (11), wherein at least one second detent contour (63) is fixedly connected to the valve spool (30) or fixedly to the housing (20) in the direction of the longitudinal axis (11), wherein each second detent contour (63) can be brought into engagement with the at least one second detent element (62) such that the valve spool (30) is held in an associated second detent position (60), wherein there is no coupling between the actuating device (70) and the at least one second detent element (62). [11] Directional control valve according to claim 10, insofar as it refers back to claim 9, wherein the at least one second detent contour (63) is arranged directly on the retaining part (100). [12] Directional control valve according to one of the preceding claims, wherein at least one position sensing means (110) is provided with which the relative position between the valve spool (30) and the housing (20) can be measured. [13] Directional control valve according to one of the preceding claims, wherein a pressure sensor (122) is provided with which a load pressure at the directional control valve (10; 10') can be measured, wherein a control device (123) is provided to which the actuating device (70) and the pressure sensor (122) are connected, wherein the control device (123) is configured to cancel an engagement already carried out between the at least one first detent element (52) and a first detent contour (53) using the actuating device (70) when the said load pressure exceeds a predetermined value.

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