Hydraulic valve, especially for a hydraulic parking lock system, and hydraulic parking lock system with the hydraulic valve

Abstract

Hydraulic valve (10), in particular for a hydraulic parking lock system (11), comprising a valve spool (12), a valve housing (13), a first compression spring (14) and a second compression spring (15), wherein the valve spool (12) has a first spool part (16) and a second spool part (17) which are arranged to be axially movable relative to each other, and wherein the second compression spring (15) supports the second spool part (17) in a first axial direction (18) against the valve housing (13), wherein the valve housing (13) has a control port (19), at least one first operating port (20) and at least one second operating port (21), characterized by the fact that the first valve part (16) has connecting pockets (22, 23), wherein connections between the at least one first operating port (20) and the at least one second operating port (21) can be established through the connecting pockets (22, 23) of the first valve part (16).

Description

[0001] The invention relates to a hydraulic valve, in particular for a hydraulic parking lock system, and a hydraulic parking lock system with the hydraulic valve.

[0002] From EP 0 197 467 B1, a hydraulic valve is already known comprising a valve spool, a valve housing, a first compression spring and a second compression spring, wherein the valve spool has a first spool part and a second spool part which are arranged to be axially movable relative to each other, and wherein the second compression spring supports the second spool part in a first axial direction against the valve housing.

[0003] The invention is based in particular on the objective of providing an advantageously compact and versatile hydraulic valve, especially for a hydraulic parking lock system. This objective is achieved by a hydraulic valve according to claim 1 and by a hydraulic parking lock system according to claim 10. Further embodiments of the invention are set forth in the dependent claims.

[0004] The invention relates to a hydraulic valve, in particular for a hydraulic parking lock system, comprising a valve spool, a valve housing, a first compression spring and a second compression spring, wherein the valve spool has a first spool part and a second spool part which are arranged to be axially movable relative to each other, and wherein the second compression spring supports the second spool part in a first axial direction against the valve housing.

[0005] It is further assumed that the valve housing has a control port, at least one first operating port, and at least one second operating port. According to the invention, the first spool section has connecting pockets, wherein connections between the at least one first operating port and the at least one second operating port can be established through the connecting pockets of the first spool section. Preferably, the hydraulic valve is provided for at least one actuation of the parking lock. Particularly preferably, the hydraulic valve is provided for combining several functions. The hydraulic valve, in particular, forms a combination of a switching spool and a check valve. This allows several functions to be implemented in one hydraulic valve, which is particularly advantageous. In particular, the number of components in the system, especially in the parking lock system, can be kept to a minimum.The design according to the invention therefore makes it possible to provide a particularly advantageously compact and versatile hydraulic valve. In particular, it makes possible to provide a hydraulic valve with a small installation space requirement.

[0006] In this context, a "valve slide" is understood to mean, in particular, a displaceable component of the hydraulic valve. Preferably, it is understood to mean a component of the hydraulic valve which, depending on its position relative to the valve housing of the hydraulic valve, defines a switching position of the hydraulic valve. Preferably, the valve slide is a switching slide. Furthermore, the valve slide is preferably designed to be hydraulically displaced. The valve slide consists of at least two separately displaceable slide parts. Furthermore, in this context, an "axial direction" is understood to mean, in particular, a direction that extends parallel to a displacement direction of the valve slide. Preferably, the axial direction extends parallel to a main extension direction of the hydraulic valve.In this context, the "principal extension direction" of an object is understood to be, in particular, a direction that runs parallel to the longest edge of the smallest geometric cuboid that just completely encloses the object.

[0007] In this context, a "control port" of the hydraulic valve is understood to mean, in particular, a port of the hydraulic valve that is provided for adjusting the valve spool. Preferably, the control port is designed to move the valve spool to a defined switching position depending on the pressure applied to the control port. Furthermore, in this context, a "operating port" of the hydraulic valve is understood to mean, in particular, a port switched by the hydraulic valve. Preferably, the hydraulic valve is designed to disconnect and / or connect at least two operating ports depending on a switching position. Furthermore, in this context, a "connecting pocket" is understood to mean, in particular, a recess in the spool part.Preferably, this refers in particular to a section of the valve part with a diameter reduced compared to a maximum diameter. Preferably, the valve part in the area of ​​the connecting pocket is permeable to an operating medium, particularly regardless of its position. Preferably, the connecting pocket is provided for connecting at least two valve chambers, each connected to an operating port.

[0008] In a further development of the invention, it is proposed that the first compression spring supports the first slide part against the valve housing in the first axial direction. Preferably, the first compression spring has a lower, and in particular a significantly lower, spring force than the second compression spring. More preferably, the first compression spring has a significantly lower spring rate than the second compression spring. Particularly preferably, the spring rate of the first compression spring is a maximum of 20%, more preferably a maximum of 10%, and most preferably a maximum of 5% of the spring rate of the second compression spring. This makes it possible, in particular, to move the slide part into an initial position in an unactuated state, with an initial position being defined by the valve housing. It makes it possible, in particular, to adjust the first slide part against the spring force of the first compression spring by means of the control connection.Preferably, the two compression springs can be used to implement two different pressure levels, which are required to move the slide parts.

[0009] A further development provides that the first valve section has a first axial displacement range in which it can be moved in the first axial direction from an initial axial position to a first position relative to the second valve section, against the spring force of the first compression spring. The connecting pockets and operating ports are designed such that the first and second operating ports are separated from each other within this first axial displacement range. This allows for particularly advantageous switching of the hydraulic valve. In this context, a "displacement range" is understood to mean a defined axial movement range of the first valve section relative to the valve body, within which the valve section performs a predetermined function.

[0010] Preferably, the displacement range is defined by two slider positions, between which the displacement range extends.

[0011] It is further proposed that the first slide section has a second axial displacement range in which the first slide section is movable in the first axial direction from the first position to a second position where the first slide section abuts the second slide section, relative to the second slide section, against the spring force of the first compression spring, wherein the connecting pockets are designed such that the first operating port and the second operating port are connected to each other in the second axial displacement range. This allows for particularly advantageous switching of the hydraulic valve. Specifically, the first operating port and the second operating port can be connected by means of the first slide section.

[0012] It is further proposed that the first valve section has a third axial displacement range in which the first valve section, together with the second valve section, can be moved at least against the spring force of the second compression spring up to a third position, wherein the connecting pockets are designed such that the first operating port and the second operating port are separated from each other in the third position. This allows, in particular, advantageous switching capability of the hydraulic valve. Furthermore, it allows the second valve section to be actuated by means of the first valve section. In particular, this allows both valve sections to be actuated with a single control port.

[0013] In a further development, it is proposed that the second slide part be arranged coaxially to the first slide part. This allows for a particularly advantageous arrangement of the slide parts.

[0014] In a further embodiment, the second slide part has a sleeve section and the first slide part has a piston section, with the piston section of the first slide part being arranged within the sleeve section of the second slide part. This allows for a particularly advantageous arrangement of the slide parts. In particular, a more compact arrangement of the slide parts can be achieved. Furthermore, reliable guidance of the first slide part can be achieved.

[0015] In a further development, it is proposed that the first slide part has a first sliding edge and the second slide part has a stop edge, which limit the movement of the first slide part relative to the second slide part in the first axial direction. Preferably, the stop edge of the second slide part serves as a stop for the first slide part, with the first slide part abutting the stop edge in a stop position. This ensures, in particular, that the first slide part reliably engages the second slide part. It is especially advantageous to provide a stop. Preferably, a stop can be formed using edges that are already present. In this context, a "sliding edge" is understood to mean, in particular, a circumferentially extending edge of one of the slide parts.Preferably, the slide edge is arranged on an outer circumference of the first slide part. Preferably, the slide edge particularly defines a connecting pocket. In this context, a "stop edge" is understood to be, in particular, a circumferentially extending edge of one of the slide parts. Preferably, the slide edge is arranged on an outer circumference of the second slide part and serves both as a stop for the second slide part on the valve housing and as a stop for the first slide part on the second slide part.

[0016] It is further proposed that, as a further development, the first operating port is arranged downstream of the control port in the first axial direction, and the second operating port is arranged downstream of the first operating port in the first axial direction. Preferably, therefore, the control port, the first operating port, and the second operating port are arranged sequentially in this order in the first axial direction. This allows for a particularly advantageous arrangement of the operating ports and the control port.

[0017] Furthermore, the invention relates to a hydraulic parking lock system, in particular for a motor vehicle, comprising a hydraulic line, a piston-cylinder unit, a hydraulic cooling or lubrication system, and at least one hydraulic valve according to the invention. It is proposed that the control port and the first operating port of the hydraulic valve are connected to the hydraulic line for actuating a hydraulic piston-cylinder unit, and that the second operating port is connected to the hydraulic cooling or lubrication system.

[0018] Preferably, the piston-cylinder unit is formed, in particular, by a piston-cylinder unit for actuating, especially directly actuating, the parking lock. Preferably, the hydraulic cooling or lubrication system is provided for cooling and / or lubricating an electric motor, especially in a motor vehicle. This allows for a particularly advantageously compact hydraulic parking lock system. Preferably, the hydraulic valve can function as both a check valve and a spool valve. This allows for a particularly advantageously small installation space requirement.

[0019] For a further development of the hydraulic parking lock system, it is proposed that the hydraulic valve have a third operating port, arranged axially between the first and second operating ports and connected to the cooling or lubrication system via an orifice plate. This allows for a particularly advantageous arrangement of the operating ports and the control port. In particular, it enables advantageous switching of the hydraulic valve.

[0020] A further development of the hydraulic parking lock system provides that the first spool section of the hydraulic valve has a first connecting pocket designed to connect the first and third operating ports, and a second connecting pocket designed to connect the third and second operating ports. Preferably, a connection between the first and second operating ports can be achieved via the first and second connecting pockets. This allows for a particularly advantageous arrangement of the operating ports and the control port.

[0021] Further advantages will become apparent from the following description of the figures. The figures illustrate an embodiment of the invention. The figures, the description of the figures, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0022] This shows: Fig. 1 a hydraulic parking lock system with a hydraulic line, with a piston cylinder unit, with a hydraulic cooling or lubrication system and with a hydraulic valve in a schematic representation and Fig. 2 the hydraulic valve of the hydraulic parking lock system with a valve spool, with a valve body, with a first compression spring and with a second compression spring in a schematic sectional view.

[0023] Fig. Figure 1 shows a hydraulic parking lock system 11. The hydraulic parking lock system 11 is intended for use in a motor vehicle. The motor vehicle is, in particular, a hybrid or electric motor vehicle. The motor vehicle has an electric motor 45. The hydraulic parking lock system 11 has a hydraulic line 35 and a piston-cylinder unit 36. The hydraulic line 35 is provided for actuating the piston-cylinder unit 36. The piston-cylinder unit 36 ​​is actuated depending on a pressure and / or a hydraulic volume in the hydraulic line 35. For this purpose, the hydraulic line 35 is connected to an actuating port of the piston-cylinder unit 36. The actuating port of the piston-cylinder unit 36 ​​has, for example, a diameter of 8 mm.Depending on the pressure and / or hydraulic volume in the hydraulic line 35, a spring-loaded piston 41 of the piston-cylinder unit 36 ​​is moved into a defined position. Depending on the position of the spring-loaded piston 41, the position of the parking lock 40 changes. The position of the spring-loaded piston 41 is monitored by a position sensor 42. The piston-cylinder unit 36 ​​is designed to actuate, in particular directly actuate, a parking lock 40, specifically a parking lock pawl, of the hydraulic parking lock system 11.

[0024] Furthermore, the hydraulic parking lock system 11 includes a hydraulic pump 44 driven by a motor 43. The pump 44 is designed to pump a hydraulic medium through the hydraulic line 35. The hydraulic medium is circulated through the hydraulic line 35 by means of the pump 44. The pump 44 is connected between the hydraulic line 35.

[0025] Furthermore, the hydraulic parking lock system 11 includes a hydraulic cooling or lubrication system 37. The hydraulic cooling or lubrication system 37 is intended for cooling and lubricating an electric motor 45 of the motor vehicle.

[0026] The hydraulic parking lock system 11 further comprises a hydraulic valve 10. The hydraulic valve 10 is for the hydraulic parking lock system 11. The hydraulic valve 10 has a valve spool 12 and a valve body 13. The valve spool 12 is guided in the valve body 13. The valve body 13 has a control port 19, a first operating port 20, and a second operating port 21. Furthermore, the hydraulic valve 10 has a third operating port 38. The valve body 13 has the third operating port 38. The control port 19 and the first operating port 20 of the hydraulic valve 10 are connected to the hydraulic line 35 for actuating the hydraulic piston cylinder unit 36. The second operating port 21 is connected to the hydraulic cooling or lubrication system 37. The third operating port 38 is connected to the cooling or lubrication system 37 via an orifice plate 39.The aperture 39 has, for example, a diameter of 0.8 mm. The flow rate through the third operating port 38 is reduced compared to the flow rate through the second operating port 21.

[0027] The first operating port 20 is arranged downstream of the control port 19 in the first axial direction 18, and the second operating port 21 is arranged downstream of the first operating port 20 in the first axial direction 18. The third operating port 38 is arranged between the first operating port 20 and the second operating port 21 in the axial direction 18.

[0028] The valve spool 12 of the hydraulic valve 10 is designed in two parts. The valve spool 12 of the hydraulic valve 10 has a first spool part 16 and a second spool part 17. The first spool part 16 and the second spool part 17 are arranged to be axially movable relative to each other. The second spool part 17 is arranged coaxially with the first spool part 16. The first spool part 16 and the second spool part 17 are arranged axially one behind the other. The first spool part 16 is partially guided within the second spool part 17. The second spool part 17 has a sleeve section 31, and the first spool part 16 has a piston section 32. The piston section 32 of the first spool part 16 is arranged within the sleeve section 31 of the second spool part 17. The first slide part 16 has a fully cylindrical basic shape, with one end facing the second slide part 17 forming the piston area 32.The second slide part 17 has a hollow cylindrical basic shape, with one end facing the first slide part 16 forming the sleeve area 31 (. Fig. 2).

[0029] Furthermore, the hydraulic valve 10 has a first compression spring 14 and a second compression spring 15. The first compression spring 14 supports the first spool section 16 against the valve housing 13 in the first axial direction 18. The second compression spring 15 supports the second spool section 17 against the valve housing 13 in a first axial direction 18. The first compression spring 14 has a significantly lower spring rate than the second compression spring 15. The first compression spring 14 and the second compression spring 15 are arranged coaxially with the first spool section 16. In an assembled state, the first compression spring 14 is partially located inside the second spool section 17. The first compression spring 14 bears against the piston area 32 of the first spool section 16 at one end. Furthermore, the first compression spring 14 bears against the valve housing 13 at a second end, though this second end is not visibly supported.The second compression spring 15, in its assembled state, is arranged to encompass the second slide section 17. The second compression spring 15 bears at one end against the sleeve area 31 of the second slide section 17. Furthermore, the second end of the second compression spring 15 bears, in a less visible manner, against a stop element 46. The stop element 46 serves as a stop for the second slide section 17. Axial movement of the second slide section 17 is limited on one side by the valve housing 13 and on the other side by the stop element 46. In its initial position, in which the second slide section 17 is supported against the valve housing 13 by the second compression spring 15, the second slide section 17 is spaced apart from the stop element 46. For example, in this initial position, the second slide section 17 is spaced 2 mm apart from the stop element 46.The stop element 46 is not visibly connected to the valve housing 13. Furthermore, the stop element 46 is at least substantially identical in design to the second slide part 17, but installed in the opposite direction. However, a different design for the stop element 46, which would appear sensible to a person skilled in the art, would also be conceivable. In its assembled state, the second compression spring 15 is arranged to encompass the second slide part 17 and the stop element 46.

[0030] A space 48 enclosed between the stop element 46, the second slide valve part 17 and the first slide valve part 16 is filled with a hydraulic medium. The space 48 is connected via a connection 49 to a compensating reservoir 50, which allows for the compensation of any changes in the volume of the space 48.

[0031] Furthermore, the first valve section 16 has two connecting pockets 22, 23. The connecting pockets 22, 23 are each formed by recesses in the valve section 16. The first valve section 16 has a cylindrical basic shape, with the diameter of the first valve section 16 being reduced in the area of ​​the connecting pockets 22, 23 compared to its maximum diameter. The first valve section 16 also has a cylindrical shape in the area of ​​the connecting pockets 22, 23. Furthermore, the first valve section 16 has a reduced diameter at the piston area 32. Connections between the first operating port 20 and the second operating port 21 can be established via the connecting pockets 22, 23 of the first valve section 16. The first operating port 20, the second operating port 21, and the third operating port 38 each form valve chambers radially encompassing the first valve section 16.The control port 19 also forms a valve chamber radially encompassing the first valve section 16. The valve chambers are each separated from adjacent valve chambers by partition walls of the valve housing 13. The partition walls of the valve housing 13 each have an opening with the maximum diameter of the first valve section 16, through which the first valve section 16 is guided. If one of the connecting pockets 22, 23 is at the level of one of the partition walls of the valve housing 13, the valve chambers separated by the respective partition wall are connected. A first partition wall of the valve housing 13 abuts the valve chamber of the first operating port 20 with a first housing edge 55 and the valve chamber of the third operating port 38 with a second housing edge 56.A second partition wall of the valve housing 13 abuts the valve chamber of the third operating port 38 with a third housing edge 57 and the valve chamber of the second operating port 21 with a fourth housing edge 58. A third partition wall of the valve housing 13 is arranged between the first operating port 20 and the control port 19.

[0032] The first valve section 16 of the hydraulic valve 10 has a first connecting pocket 22, which is designed to connect the first operating port 20 and the third operating port 38, and a second connecting pocket 23, which is designed to connect the third operating port 38 and the second operating port 21. The first connecting pocket 22 is bounded by a second valve edge 51 and a third valve edge 52. The second connecting pocket 23 is bounded by a fourth valve edge 53 and a fifth valve edge 54. The first valve section 16 is axially symmetrical with respect to an axis 47 running parallel to the axial direction 18. The first valve section 16 has a first valve edge 33. The second valve section 17 also has a stop edge 34, which limits the movement of the first valve section 16 relative to the second valve section 17 in the first axial direction 18.The stop edge 34 of the second slide part 17 serves as a stop for the first slide part 16, wherein the first slide part 16 in a stop position with the first slide edge 33 abuts the stop edge 34.

[0033] The first slide section 16 has a first axial displacement range 24, in which the first slide section 16 can be moved in the first axial direction 18 from an initial axial position 25, in which the first slide section 16 is supported against the valve housing 13 by means of the first compression spring 14, to a first position 26 relative to the second slide section 17 against the spring force of the first compression spring 14. In the first position 26, the second slide edge 51 of the first slide section 16 is axially aligned with the second housing edge 56 of the first intermediate wall, and the fourth slide edge 53 of the first slide section 16 is axially aligned with the fourth housing edge 58 of the second intermediate wall. The first displacement range 24 extends, for example, over 2 mm.The connecting pockets 22, 23 and the operating ports 20, 21 are designed such that the first operating port 20 and the second operating port 21 are separated from each other in the first axial displacement range 24. In the first axial displacement range 24, the first operating port 20, the second operating port 21 and the third operating port 38 are separated from each other.

[0034] Furthermore, the first slide section 16 has a second axial displacement range 27, in which the first slide section 16 is movable relative to the second slide section 17 in the first axial direction 18, from the first position 26 to a second position 28, where the first slide section 16 abuts the second slide section 17, against the spring force of the first compression spring 14. In the second position 28, the first slide section 16 abuts the stop edge 34 of the second slide section 17 with its first slide edge 33. The second displacement range 27 extends, for example, over 1 mm. The connecting pockets 22, 23 are designed such that the first operating port 20 and the second operating port 21 are connected to each other in the second axial displacement range 27. In the second axial displacement area 27, the first operating port 20, the second operating port 21 and the third operating port 38 are connected to each other.

[0035] Furthermore, the first slide section 16 has a third axial displacement range 29, in which the first slide section 16, together with the second slide section 17, is movable at least against the spring force of the second compression spring 15 up to a third position 30. In the third axial displacement range 29, the first slide section 16, together with the second slide section 17, is movable against the spring force of the first compression spring 14 and the second compression spring 15 up to the third position 30, in which the second slide section 17 rests against the stop element 46. The third displacement range 29 extends, for example, over 2 mm. The connecting pockets 22, 23 are designed such that the first operating port 20 and the second operating port 21 are separated from each other in the third position 30. In the third position 30, the first operating port 20, the second operating port 21, and the third operating port 38 are separated from each other.In the third axial displacement range 29, the first slide section 16 separates the first operating port 20, the second operating port 21, and the third operating port 38 from each other after 1 mm from the second position 28. After 2 mm from the second position 28, the second slide section 17 abuts the stop element 46.

[0036] The various displacement ranges 24, 27, 29 of the first slide section 16 are in the Fig. 2 shown starting from an axial end of the first slide part 16 facing away from the second slide part 17.

[0037] The hydraulic valve 10 combines two functions required in the hydraulic parking lock system 11 in one operation, namely that of a check valve and that of a sliding gate valve.

[0038] The function of the check valve prevents air from being drawn in when the transmission is in position "P" and / or when "P" is engaged. The hydraulic valve 10 prevents air or a hydraulic medium from entering the hydraulic line 35 from the cooling or lubrication system 37 via the hydraulic valve 10. The hydraulic valve 10 is closed when there is a relative overpressure on one side of the cooling or lubrication system 37 relative to one side of the piston-cylinder unit 36.

[0039] The function of the switching valve ensures that the cooling of the electric motor 45 is switched off when "nP" (non-prone) is engaged. To engage "nP", the system pressure is increased, for example to 12 bar, after which the pump 44 is activated according to the cooling requirements of the electric motor 45. 12 bar corresponds, for example, to the third position 30 of the first valve section 16. However, the pressure upstream of the hydraulic valve 10 in the hydraulic line 35 must decrease, specifically below 4 bar, for the hydraulic valve 10 to reopen. 4 bar corresponds, for example, to the second position 28 of the first valve section 16. Especially at very low oil temperatures, the system pressure can decrease very slowly. For this purpose, the hydraulic valve 10 has a bypass function, which allows the system pressure to decrease more quickly.This can be achieved in particular by ensuring that, when the first slide valve section 16 moves from a third position 30 to a second position, the flow opens even before the second position is reached. The two compression springs 14, 15 with different spring rates provide two pressure stages and thus two partial functions: under low pressure, the first slide valve section 16 moves against the first compression spring 14 to the second position 28, and under high pressure, it moves against both the first compression spring 14 and the second compression spring 15 to the third position 30. Reference symbol list 10 Hydraulic valve 11 Parking barrier system 12 valve slides 13 Valve housings 14 Compression spring 15 compression spring 16 Slider part 17 Slider part 18 direction 19 Control connection 20 operating connection 21 Operating connection 22 connecting pockets 23 connecting pockets 24 shift range 25 Starting position 26th position 27 Displacement range 28th position 29 Displacement range 30 Position 31 Sleeve area 32 piston area 33 Slider edge 34 Stop edge 35 Hydraulic line 36 piston cylinder unit 37 Cooling or lubrication system 38 Operating connection 39 aperture 40 parking restrictions 41 pistons 42 Position sensor 43 Engine 44 Pump 45 electric motor 46 Stop element 47 axle 48 Room 49 connection 50 expansion tanks 51 Slider edge 52 Slider edge 53 Slider edge 54 Slider edge 55 Case edge 56 Case edge 57 Case edge 58 Case edge

Claims

[1] Hydraulic valve (10), in particular for a hydraulic parking lock system (11), comprising a valve spool (12), a valve housing (13), a first compression spring (14) and a second compression spring (15), wherein the valve spool (12) has a first spool part (16) and a second spool part (17) which are arranged to be axially movable relative to each other, and wherein the second compression spring (15) supports the second spool part (17) in a first axial direction (18) against the valve housing (13), wherein the valve housing (13) has a control port (19), at least one first operating port (20) and at least one second operating port (21), characterized by , that the first valve part (16) has connecting pockets (22, 23), wherein connections between the at least one first operating port (20) and the at least one second operating port (21) can be established through the connecting pockets (22, 23) of the first valve part (16). [2] Hydraulic valve (10) according to claim 1, characterized by , that the first compression spring (14) supports the first slide part (16) in the first axial direction (18) against the valve housing (13). [3] Hydraulic valve (10) according to claim 1 or 2, characterized by, that the first slide part (16) has a first axial displacement range (24) in which the first slide part (16) is movable in the first axial direction (18) from an initial axial position (25) to a first position (26) relative to the second slide part (17) against the spring force of the first compression spring (14), wherein the connecting pockets (22, 23) and the operating ports (20, 21) are designed such that the first operating port (20) and the second operating port (21) are separated from each other in the first axial displacement range (24). [4] Hydraulic valve (10) according to claim 3, characterized by, that the first slide part (16) has a second axial displacement range (27) in which the first slide part (16) is movable in the first axial direction (18) from the first position (26) to a second position (28) where the first slide part (16) abuts the second slide part (17) against the spring force of the first compression spring (14), wherein the connecting pockets (22, 23) are designed such that the first operating port (20) and the second operating port (21) are connected to each other in the second axial displacement range (27). [5] Hydraulic valve (10) according to claim 3, characterized by, that the first slide part (16) has a third axial displacement range (29) in which the first slide part (16) together with the second slide part (17) is movable at least against the spring force of the second compression spring (15) up to a third position (30), wherein the connecting pockets (22, 23) are designed such that the first operating port (20) and the second operating port (21) are separated from each other in the third position (30). [6] Hydraulic valve (10) according to any of the preceding claims, characterized by , that the second slide part (17) is arranged coaxially to the first slide part (16). [7] Hydraulic valve (10) according to any of the preceding claims, characterized by, that the second slide part (17) has a sleeve area (31) and the first slide part (16) has a piston area (32), wherein the piston area (32) of the first slide part (16) is arranged within the sleeve area (31) of the second slide part (17). [8] Hydraulic valve (10) according to any of the preceding claims, characterized by , that the first slide part (16) has a first slide edge (33) and the second slide part (17) has a stop edge (34) which limits the movement of the first slide part (16) relative to the second slide part (17) in the first axial direction (18). [9] Hydraulic valve (10) according to any of the preceding claims, characterized by , that the first operating port (20) is arranged in the first axial direction (18) behind the control port (19) and the second operating port (21) is arranged in the first axial direction (18) behind the first operating port (20). [10] Hydraulic parking lock system (11), in particular for a motor vehicle, comprising a hydraulic line (35), a piston cylinder unit (36), a hydraulic cooling or lubrication system (37) and at least one hydraulic valve (10) according to one of the preceding claims, characterized by , that the control port (19) and the first operating port (20) of the hydraulic valve (10) are connected to the hydraulic line (35) for actuating the hydraulic piston cylinder unit (36) and the second operating port (21) is connected to the hydraulic cooling or lubrication system (37). [11] Hydraulic parking lock system (11) according to claim 10, characterized by , that the hydraulic valve (10) has a third operating port (38) which is arranged in the axial direction (18) between the first operating port (20) and the second operating port (21) and which is connected to the cooling or lubrication system (37) via an orifice (39). [12] Hydraulic parking lock system (11) according to claim 11, characterized by , that the first slide part (16) of the hydraulic valve (10) has a first connecting pocket (22) which is intended to connect the first operating port (20) and the third operating port (38), and a second connecting pocket (23) which is intended to connect the third operating port (38) and the second operating port (21).

Images