Switching valve and switching unit for switching at least two fluid channels
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- MANN HUMMEL GMBH
- Filing Date
- 2024-08-22
- Publication Date
- 2026-07-01
Smart Images
Figure EP2024073535_27022025_PF_FP_ABST
Abstract
Description
[0001] Switching valve and switching unit for switching at least two fluid channels
[0002] Technical area
[0003] The invention relates to a switching valve for switching at least two fluid channels and a switching unit for a switching valve.
[0004] State of the art
[0005] Electrically switched switching valves for switching a hydraulic flow gallery with at least two fluid channels are known. Conventional valves maintain the open position against oil pressure and thus have a defined power consumption depending on the holding force in the open or closed position.
[0006] DE 20 2005 011 092 U1 describes a locking latch with a locking pin that can be axially driven by a rotary motion. The radial pin can be engaged in at least one axial end groove by reducing the force of a spring in such a way that, before reversing, the radial pin must be axially displaced by axial pulling or pushing against the force of the spring and thus unlocked. A radial screw slot / radial pin guide is provided between the locking pin and the housing sleeve to move the locking pin into its position, which locks or unlocks at least two components.
[0007] DE 20 2008 013 348 U1 discloses a detent pin with a locking mechanism, in which the actuation of the detent pin for locking or unlocking always occurs in a single actuation direction, either by pushing or pulling. The detent pin essentially has a type of "ballpoint pen mechanism" as a sliding and locking mechanism for locking in the working and rest positions. Thus, the detent pin is actuated only by pushing (or pulling), against or by means of the force of a spring. The sliding and locking mechanism essentially corresponds in function to the sliding gate of a ballpoint pen guide. It is therefore a conventional switching mechanism, such as is used in ballpoint pens and the like. DE 20 2009 014 685 U1 describes a sliding arrangement, in particular an extension device for drawers, sliding doors, hinged doors, etc.Disclosed is an ejection arrangement comprising a sliding piece that is adjustable between an inserted position and an extended position by means of a spring element. The sliding piece is spring-loaded along a first adjustment path and can be adjusted without spring loading in a freewheel of the ejection device along a subsequent second adjustment path.
[0008] Disclosure of the invention
[0009] An object of the invention is to provide an efficient switching valve for switching at least two fluid channels.
[0010] A further object of the invention is to provide an efficient switching unit for a switching valve.
[0011] The above object is achieved according to one aspect of the invention with a switching valve for switching at least two fluid channels, at least comprising a valve housing in which a piston is arranged to control a fluid flow between at least two valve openings, which are fluidically connected to the fluid channels during intended use, a first return spring, by means of which the piston experiences a return force in the axial direction during intended operation, and a switching unit which is designed to bring and hold the piston against the return force from at least one first switching position into at least one second switching position, and to return it from the at least one second switching position to the at least one first switching position,wherein the piston is held in the at least one first switching position and the at least one second switching position without supplying energy.,
[0012] According to a further aspect of the invention, the further object is achieved by a switching unit for a switching valve, at least comprising a base ring, with guide grooves and holding ribs arranged alternately on the inner circumference, an actuator which is guided in the base ring in the guide grooves in the axial direction and by means of which a piston is movable in the axial direction and which has first control surfaces inclined in the circumferential direction, a switching ring which is guided in the base ring and is movable in the axial direction and has second control surfaces complementary to the first control surfaces in the circumferential direction, which second control surfaces are provided for contacting the first control surfaces, and a second return spring, by means of which the switching is supported on the actuator in the axial direction.
[0013] Advantageous embodiments and advantages of the invention emerge from the further claims, the description and the drawing.
[0014] According to one aspect of the invention, a switching valve for switching at least two fluid channels is proposed, comprising at least one valve housing in which a piston is arranged to be movable in an axial direction for controlling a fluid flow between at least two valve openings, which are fluidically connected to the fluid channels during intended use, a first return spring by means of which the piston experiences a return force in the axial direction during intended operation, and a switching unit which is designed to bring and hold the piston against the return force from at least one first switching position into at least one second switching position, and to return it from the at least one second switching position into the at least one first switching position.The piston is held in the at least one first switching position and the at least one second switching position without supplying energy, in particular electrical or magnetic energy.
[0015] The invention describes an electrically switched switching valve that actively switches a hydraulic flow gallery. The switching valve connects two or more fluid channels. For this purpose, the two fluid channels to be connected are both intersected by a switching channel. The switching valve is inserted into this switching channel. The switching valve comprises at least one piston, a return spring, and a switching unit that allows the at least one first and at least one second switching position of the switching valve to be maintained without the supply of energy, in particular electrical or magnetic energy. The proposed switching valve thus has end positions that are held without current, thus saving energy.
[0016] It is also conceivable to use the switching valve to switch and / or distribute gas flows.
[0017] According to a favorable embodiment of the switching valve, the switching unit can be configured to move the piston from the at least one first switching position to the at least one second switching position and back again by the action of a control pin movable in the axial direction. The switching process can be initiated and controlled via the control pin. Once the switching process is initiated, the transition from one switching position to the other occurs via the internal mechanism of the switching unit.
[0018] According to a favorable embodiment of the switching valve, the control pin can be coupled to a drive, in particular an electromagnetic drive. The control pin can be controlled and moved, for example, via an electromagnetic actuator or hydraulically.
[0019] According to a favorable embodiment of the switching valve, the switching unit can comprise at least: a base ring with guide grooves and retaining ribs arranged alternately on the inner circumference, an actuator which is guided in the base ring in the guide grooves in the axial direction and by means of which the piston is movable in the axial direction and which has first control surfaces inclined in the circumferential direction, a switching ring which is guided in the base ring and movable in the axial direction and has second control surfaces complementary to the first control surfaces in the circumferential direction, which are provided for contacting the first control surfaces, and a second return spring, by means of which the switching ring is supported on the actuator in the axial direction. By means of the switching unit, the piston can be switched back and forth between the first and second switching positions via control by the control pin.According to a favorable embodiment of the switching valve, upon actuation of the control pin, a simultaneous axial and rotational movement of the actuator about the longitudinal axis can take place, whereby the actuator is lifted out of the guide grooves and is held in the at least one second switching position by holding ribs arranged on the base ring and extending in the axial direction.
[0020] The simultaneous axial and rotational movement of the actuator can advantageously be assisted by the restoring force of the first return spring. A rotational movement of the actuator can advantageously be initiated again via the inclined control surfaces by actuating the switching ring again via the control pin, lifting the actuator from the retaining ribs. The actuator can thus be returned to the at least one first switching position by the restoring force of the first return spring.
[0021] According to a favorable embodiment of the switching valve, the second control surfaces of the switching ring can be wedge-shaped, at least in sections, in the circumferential direction. This advantageously enables the rotational movement of the actuator to be effected.
[0022] According to a favorable design of the switching valve, the switching ring can have radially projecting guide lugs that engage, as intended, in the guide grooves of the base ring. In this way, the switching ring can be advantageously guided laterally in the guide grooves of the base ring during its movement in the axial direction.
[0023] According to a favorable embodiment of the switching valve, the retaining ribs can have locking surfaces at their axially free end, in which the actuator is held in the at least one second switching position. The first control surfaces of the actuator can thus interact with the locking surfaces to hold the actuator in the second switching position. According to a favorable embodiment of the switching valve, the actuator can have guide elements extending in the axial direction on a circumference, which engage, as intended, in the guide grooves of the base ring. The actuator can also be advantageously guided laterally during a movement in the axial direction.
[0024] According to a favorable embodiment of the switching valve, the guide elements can have the first control surfaces at their axially free ends. The first control surfaces of the actuator can thus advantageously interact with the locking surfaces of the retaining ribs to hold the actuator in the second switching position.
[0025] According to a favorable embodiment of the switching valve, the locking surfaces can have locking lugs arranged in the circumferential direction, to which the guide elements are secured in the at least one second switching position. In this way, the actuator can be held in the second switching position.
[0026] According to a favorable design of the switching valve, the retaining ribs can have circumferentially adjoining locking surfaces at their axially free end, which are arranged at different heights in the axial direction. This advantageously makes it possible to set a new switching position with each additional switching pulse from the control pin, similar to a step-by-step switching operation.
[0027] According to a favorable design of the switching valve, the piston and the actuator can each have a bore to compensate for a fluid volume during movement of the piston and actuator. This prevents the enclosed fluid volume from impeding the movements of the piston and actuator.
[0028] According to a favorable embodiment of the switching valve, the switching ring can have a receptacle and / or the actuator can have an inner section for guiding the second return spring. This allows the second return spring to remain securely guided during the movement of the actuator.According to a further aspect of the invention, a switching unit for a switching valve is proposed, comprising at least a base ring with guide grooves and holding ribs arranged alternately on the inner circumference, an actuator which is guided in the base ring in the guide grooves in the axial direction and by means of which a piston is movable in the axial direction and which has first control surfaces inclined in the circumferential direction, a switching ring which is guided in the base ring and is movable in the axial direction and has second control surfaces complementary to the first control surfaces in the circumferential direction, which second control surfaces are provided for contacting the first control surfaces, and a second return spring, by means of which the switching ring is supported on the actuator in the axial direction.
[0029] The switching unit consisting of base ring, actuator, switching ring and return spring could also be advantageously used as a retrofit solution to convert a standard valve into a switching valve with a de-energized end position.
[0030] In an alternative embodiment of the switching valve, the base ring, in particular the contour of the base ring, is formed in the valve housing, in particular formed in one piece.
[0031] Short description of the drawings
[0032] Further advantages will become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.
[0033] Examples include:
[0034] Figure 1 is an isometric view of a switching valve for switching at least two fluid channels according to an embodiment of the invention;
[0035] Figure 2 is an exploded view of the switching valve; Figure 3 is an enlarged exploded view of a part of the switching valve with a switching unit according to an embodiment of the invention;
[0036] Figure 4 shows a sectional view of the switching valve mounted in a valve block in a second switching position;
[0037] Figure 5 shows a sectional view of the switching valve mounted in a valve block in a first switching position;
[0038] Figure 6 is an isometric view of a base ring of the switching valve;
[0039] Figure 7 is an isometric view of an actuator of the switching valve;
[0040] Figure 8 is an isometric view of a switching ring of the switching valve; and
[0041] Figure 9 is an isometric view of the base ring with the switching ring of the switching valve inserted.
[0042] Embodiments of the invention
[0043] In the figures, identical or similar components are numbered with the same reference numerals. The figures show only examples and are not to be understood as limiting.
[0044] To explain the invention, Figure 1 shows an isometric view of a switching valve 100 for switching at least two fluid channels 202, 204 according to an embodiment of the invention. Figure 2 shows an exploded view of the switching valve 100, with Figure 3 showing the part of the switching valve 100 with the switching unit 10 enlarged.
[0045] Figure 4 shows a sectional view of the switching valve 100 mounted in a valve block 200 in a second switching position 2, while Figure 5 shows the switching valve 100 in a first switching position 1.
[0046] The switching valve 100 comprises a valve housing 110 in which a piston 120 is arranged to control a fluid flow between at least two valve openings 102, 104, which can move in an axial direction 112. During intended use, the valve openings 102, 104 are fluidly connected to the fluid channels 202, 204 of the valve block 200. Furthermore, the switching valve 100 comprises a first return spring 114, by means of which the piston 120 experiences a restoring force in the axial direction 112 during intended operation, and a switching unit 10, which is designed to move and hold the piston 120 against the restoring force from at least one first switching position 1 into at least one second switching position 2, and to return it from the at least one second switching position 2 to the at least one first switching position 1.The piston 120 is held in the at least one first switching position 1 and the at least one second switching position 2 without energy supply, in particular without electrical or magnetic energy.
[0047] The piston 120 has circumferential annular grooves 128 on its circumference, which can be designed, for example, as lubricating grooves in order to be guided within the valve housing 110 with low friction.
[0048] The switching valve 100 is arranged in a bore of the valve block 200, which intersects the two fluid channels 202, 204. The valve housing 110 is sealed against the bore of the valve block 200 by at least one radially outwardly arranged sealing element 122, for example, an O-ring.
[0049] The switching unit 10 can move the piston 120 from the at least one first switching position 1 to the at least one second switching position 2 and back again by the action of a control pin 12 movable in the axial direction 112 (see Figures 4 and 5). The control pin 12 can, for example, be coupled to a drive 14, in particular an electromagnetic drive 14. As can be seen in Figure 4, the drive 14 is screwed to the valve block 200 via the fastening flange 106 with fastening screws 108. The control pin 12 can be a component of the drive 14. Alternatively, the control pin 12 can also be driven solely by the drive 14.
[0050] The switching unit 10 comprises a base ring 20 with guide grooves 26 and holding ribs 24 arranged alternately on the inner circumference, and an actuator 40 which is guided in the base ring 20 in the axial direction 112 in the guide grooves 26 and by means of which the piston 120 is movable in the axial direction 112. The actuator 40 has first control surfaces 48 inclined in the circumferential direction 36. The switching unit 10 also has a switching ring 60 which is guided in the base ring 20 and movable in the axial direction 112 and has second control surfaces 64 complementary to the first control surfaces 48 in the circumferential direction 36, which are provided for contacting the first control surfaces 48. Furthermore, the switching unit 10 has a second return spring 80, by means of which the switching ring 60 is supported on the actuator 40 in the axial direction 112.
[0051] To illustrate the individual components of the switching unit 10, Figure 6 shows an isometric view of the base ring 20, while Figure 7 shows an isometric view of the actuator 40. Figure 8 shows an isometric view of the switching ring 60, and Figure 9 shows an isometric view of the base ring 20 with the switching ring 60 inserted.
[0052] The second control surfaces 64 of the switching ring 60 are at least partially wedge-shaped in the circumferential direction 36 with edges 70 lying therebetween.
[0053] The switching ring 60 has radially projecting guide lugs 68, which engage, as intended, in the guide grooves 26 of the base ring 20. Thus, the switching ring 60 can be guided laterally in the base ring 20.
[0054] The holding ribs 24 have at their axial free end 28 locking surfaces 30 in which the actuator 40 is held in the at least one second switching position 2.
[0055] The actuator 40 has guide elements 44 extending along a circumference 54 in the axial direction 112, which engage, as intended, in the guide grooves 26 of the base ring 20. The actuator 40 is guided laterally in the base ring 20 by these elements.
[0056] The guide elements 44 have the first control surfaces 48 at their axial free ends 46.
[0057] The locking surfaces 30 of the base ring 20 have locking lugs 32 arranged in the circumferential direction 36, to which the guide elements 44 are secured in the at least one second switching position 2. The switching ring 60 has a receptacle 72, and the actuator 40 has an inner portion 50 for guiding the second return spring 80.
[0058] The piston 120 and the actuator 40 each have a bore 52, 126 for compensating a fluid volume during movement of the piston 120 and actuator 40. This allows fluid to flow from one side of the piston 120 through the bores 52, 126 to the other side of the actuator 40 and vice versa.
[0059] Supported by the restoring force of the first return spring 114, when the control pin 12 is actuated by the switching unit 10, a simultaneous axial and rotational movement of the actuator 40 about the longitudinal axis 112 takes place. As a result, the actuator 40, which is located, for example, in the switching position 1, is lifted out of the guide grooves 26 and held in the at least one second switching position 2 by holding ribs 24 arranged on the base ring 20 and extending in the axial direction 112.
[0060] When the control pin 12 is actuated in the axial direction 112, it presses on the switching ring 60. The switching element 60 is displaced in the axial direction 112 until it hits the actuator 40, which is guided in the base ring 20. The base ring 20 is pressed in and thus fixedly connected to the valve housing 110. As soon as the actuator 40 is pushed out of the guide grooves 26 of the base ring 20, the spring force of the first return spring 114 and the second control surfaces 64 of the switching ring 60, which are inclined in the circumferential direction 66, force the actuator 40 into a rotational movement. This rotation forces the actuator 40 into the next switching position 1, 2, which is held in this switching position 1, 2 by the retaining ribs 24 in the base ring 20. When the actuator 40 is in this switching position 1, 2, the control pin 12 is inoperative. Therefore, no energy needs to be applied by the drive 14, and the actuator 40 is thus held in the switching position 1, 2 without current.
[0061] The switching ring 60 is now pushed back into its home position by the second return spring 80. As soon as a new control pulse arrives via the control pin 12 and the switching ring 60 comes into contact with the actuator 40 again, the actuator 40 is lifted out of the base ring 20 and continues to rotate. This time, the actuator 40 rotates so far that it jumps over the retaining ribs 24 and can now slide down the base ring 20 into switching position 1. This opens the switching valve 100.
[0062] The inclined second control surfaces 64 ensure that, upon renewed actuation of the switching ring 60 via the control pin 12, a rotational movement of the actuator 40 is again effected, and the actuator is lifted out of the retaining ribs 24. As a result, the actuator 40 is returned to the at least one first switching position 1 by the restoring force of the first return spring 114.
[0063] Since the base ring 20 always alternately has a continuous guide groove 26 and a guide with a holding rib 24, the switching valve 100 is opened and closed alternately.
[0064] In switching position 2, which is shown in Figure 4, the retracted piston 120 closes the fluid channel 204 so that no flow of fluid can occur between the first fluid channel 202 and the second fluid channel 204.
[0065] In switching position 1, which is shown in Figure 5, the piston 120 is in a position between the two fluid channels 202, 204, so that the valve openings 104 to the fluid channel 204 are open. The valve opening 102 to the fluid channel 202 is always open, so that fluid in the valve interior 124 can flow through the hollow cylindrical piston 120 between the two fluid channels.
[0066] In an alternative embodiment, the retaining ribs 24 can have, at their axial free end 28 in the circumferential direction 36, adjoining locking surfaces 30, which are arranged at different heights in the axial direction 112. In this way, a new switching position could be set with each additional switching pulse, similar to a step switch. The switching unit 10 comprises, as indicated in Figures 2 to 5, the base ring 20, with guide grooves 26 and retaining ribs 24 arranged alternately on the inner circumference, and the actuator 40, which is guided in the base ring 20 in the guide grooves 26 in the axial direction 112 and by means of which the piston 120 is movable in the axial direction 112. The actuator 40 has first control surfaces 48 inclined in the circumferential direction 36.The switching unit 10 further comprises the switching ring 60, which is guided in the base ring 20 and movable in the axial direction 112. It has second control surfaces 64 complementary to the first control surfaces 48 in the circumferential direction 36 and provided for contacting the first control surfaces 48. Furthermore, the switching unit 10 comprises the second return spring 80, by means of which the switching ring 60 is supported on the actuator 40 in the axial direction 112.
[0067] Advantageously, the switching unit 10 could also be used as a retrofit solution to convert a standard valve into a switching valve 100 with a de-energized switching position.
[0068] Figure 6 shows an isometric view of the base ring 20 of the switching valve 100. The base ring 20 has an outer sleeve 22 in which guide grooves 26 and holding ribs 24 are arranged alternately next to one another on an inner circumference in the axial direction.
[0069] The holding ribs 24 have at their axial free end 28 locking surfaces 30 in which the actuator 40 is held in the at least one second switching position 2.
[0070] The locking surfaces 30 have locking lugs 32 arranged in the circumferential direction 36, to which guide elements 44 of the actuator 40 can be locked in the at least one second switching position 2. An edge 34 can be seen between the locking surfaces 30 and the locking lugs 32, so that the guide elements 44 of the actuator 40 can each remain fixed to the locking surfaces 30 in the at least one second switching position 2.
[0071] Figure 7 shows an isometric view of the actuator 40 of the switching valve 100. The actuator 40 has a body 42 with guide elements 44 extending along its circumference 54 in the axial direction 112, which engage, as intended, in the guide grooves 26 of the base ring 20. Furthermore, the actuator 40 is guided laterally in the base ring 20. The guide elements 44 have the first control surfaces 48 at their axially free ends 46.
[0072] The actuator 40 has an inner portion 50 for guiding the second return spring 80.
[0073] Figure 8 shows an isometric view of the switching ring 60 of the switching valve 100. The switching ring 60, which is guided in the base ring 20 and movable in the axial direction 112, has second control surfaces 64 on an annular body 62 in the circumferential direction 36, which are complementary to the first control surfaces 48 of the actuator 40 and are provided for contacting the first control surfaces 48. Edges 70 are arranged between the control surfaces 64 inclined in the circumferential direction 66, so that the guide elements 44 of the actuator 40 can each remain fixed to the control surfaces 64 in the at least one first switching position 1.
[0074] The switching ring 60 has radially projecting guide lugs 68 on the ring body 62, which engage, as intended, in the guide grooves 26 of the base ring 20. Thus, the switching ring 60 can be guided laterally in the base ring 20.
[0075] Figure 9 shows an isometric view of the base ring 20 with the switching ring 60 of the switching valve 100 inserted. Figure 9 shows the arrangement of the switching ring 60 in the base ring 20. The switching ring 60 is arranged radially within the retaining ribs 24 of the base ring 20.
[0076] Reference symbol
[0077] 1 first switching position
[0078] 2 second switching position
[0079] 10 Switching unit
[0080] 12 Control pin
[0081] 14 Drive
[0082] 20 base ring
[0083] 22 sleeve
[0084] 24 retaining rib
[0085] 26 guide groove
[0086] 28 free end
[0087] 30 rest area
[0088] 32 locking lug
[0089] 34 edge
[0090] 36 Circumferential direction
[0091] 40 Actuator
[0092] 42 bodies
[0093] 44 Guide element
[0094] 46 free end
[0095] 48 first control surface
[0096] Section 50
[0097] 52 bore
[0098] 54 Circumferential direction
[0099] 60 circuit
[0100] 62 ring bodies
[0101] 64 second control surface
[0102] 68 Guide nose
[0103] 70 edge
[0104] 72 recording
[0105] 80 second return spring 100 switching valve
[0106] 102 Valve opening
[0107] 104 Valve opening
[0108] 106 Mounting flange 108 Mounting screw
[0109] 110 valve housing
[0110] 112 Longitudinal axis
[0111] 114 first return spring
[0112] 120 Piston 122 Sealing element
[0113] 124 Valve interior
[0114] 126 bore
[0115] 128 ring groove
[0116] 200 Valve block 202 Fluid channel
[0117] 204 Fluid channel
Claims
Claims 1 . Switching valve (100) for switching at least two fluid channels (202, 204), comprising at least - a valve housing (110) in which a piston (120) for controlling a fluid flow between at least two valve openings (102, 104) is arranged to be movable in an axial direction (112), which are fluidically connected to the fluid channels (202, 204) when used as intended, - a first return spring (114), by means of which the piston (120) experiences a return force in the axial direction (112) during normal operation, and - a switching unit (10) which is designed to bring and hold the piston (120) against the restoring force from at least one first switching position (1) into at least one second switching position (2), and to return it from the at least one second switching position (2) into the at least one first switching position (1), wherein the piston (120) is held in the at least one first switching position (1) and the at least one second switching position (2) without the supply of energy.
2. Switching valve according to claim 1, wherein the switching unit (10) is designed to move the piston (120) from the at least one first switching position (1) into the at least one second switching position (2) and back by the action of a control pin (12) movable in the axial direction (112).
3. Switching valve according to claim 2, wherein the control pin (12) is coupled to a drive (14), in particular an electromagnetic drive (14).
4. Switching valve according to claim 2 or 3, wherein the switching unit (10) comprises at least - a base ring (20) with guide grooves (26) and retaining ribs (24) arranged alternately on the inner circumference, - an actuator (40) which is guided in the base ring (20) in the axial direction (112) in the guide grooves (26) and by means of which the piston (120) is moved in the axial direction (112) and which has first control surfaces (48) inclined in the circumferential direction (36), - a switching ring (60) which is guided in the base ring (20) and is movable in the axial direction (112) and has second control surfaces (64) complementary to the first control surfaces (48) in the circumferential direction (36), which are provided for contacting the first control surfaces (48), - a second return spring (80) by means of which the switching ring (60) is supported on the actuator (40) in the axial direction (112).
5. Switching valve according to claim 4, wherein upon actuation of the control pin (12) a simultaneous axial and rotational movement of the actuator (40) about the longitudinal axis (112) takes place, whereby the actuator (40) is lifted out of the guide grooves (26) and is held in the at least one second switching position (2) by holding ribs (24) arranged on the base ring (20) and extending in the axial direction (112).
6. Switching valve according to claim 4 or 5, wherein the second control surfaces (64) of the switching ring (60) are wedge-shaped at least in sections in the circumferential direction (36).
7. Switching valve according to one of claims 4 to 6, wherein the switching ring (60) has radially projecting guide lugs (68) which engage as intended in the guide grooves (26) of the base ring (20).
8. Switching valve according to one of claims 4 to 7, wherein the holding ribs (24) have at their axial free end (28) locking surfaces (30) in which the actuator (40) is held in the at least one second switching position (2).
9. Switching valve according to one of the preceding claims, wherein the actuator (40) has guide elements (44) extending on a circumference (54) in the axial direction (112), which engage as intended in the guide grooves (26) of the base ring (20).
10. Switching valve according to claim 9, wherein the guide elements (44) have the first control surfaces (48) at their axial free ends (46).
11. Switching valve according to one of claims 8 to 10, wherein the locking surfaces (30) have locking lugs (32) arranged in the circumferential direction (36), to which the guide elements (44) are rusted in the at least one second switching position (2).
12. Switching valve according to one of claims 8 to 11, wherein the holding ribs (24) have, at their axial free end (28), latching surfaces (30) which adjoin one another in the circumferential direction (36) and are arranged at different heights in the axial direction (112).
13. Switching valve according to one of claims 4 to 12, wherein the piston (120) and the actuator (40) each have a bore (52, 126) for compensating a fluid volume during a movement of the piston (120) and actuator (40).
14. Switching valve according to one of claims 4 to 13, wherein the switching ring (60) has a receptacle (72) and / or the actuator (40) has an inner portion (50) for guiding the second return spring (80).
15. Switching unit (10) for a switching valve (100) according to one of the preceding claims, comprising at least - a base ring (20) with guide grooves (26) and retaining ribs (24) arranged alternately on the inner circumference, - an actuator (40) which is guided in the base ring (20) in the axial direction (112) in the guide grooves (26) and by means of which a piston (120) is movable in the axial direction (112) and which has first control surfaces (48) inclined in the circumferential direction (36), - a switching ring (60) which is guided in the base ring (20) and is movable in the axial direction (112) and has second control surfaces (64) complementary to the first control surfaces (48) in the circumferential direction (36), which are provided for contacting the first control surfaces (48), - a second return spring (80) by means of which the switching ring (60) is supported on the actuator (40) in the axial direction (112).