ELECTROHYDRAULIC PRESSURE REGULATOR VALVE

Description

[0001] The invention relates to an electrohydraulic pressure control valve according to the preamble of the first claim. Such pressure control valves are known as such and are used for pilot control of directional control valves, for example in construction machinery, agricultural machinery and forestry machinery. State of the art:

[0002] The commonly used pressure regulating valves, as described, for example, in German patent applications DE 44 23 103 A1 or DE 20 2010 017 049, have a valve sleeve that is inserted into a receiving bore of an end cap of a directional control valve or into a control block. This allows for large production volumes for various applications.

[0003] However, if such pressure regulating valves are used in significant quantities in small flanged control blocks that are screwed onto a device, savings can be achieved by making the pressure regulating valve flanged and thus eliminating the need for the control block.

[0004] Flangeable valves are known as such; for example, most commercially available directional control valves for stationary hydraulics are designed for flange mounting. They are typically attached using mounting plates. Flangeable pressure control valves are also known; for example, German patent application DE 10 2012 010 986 A1 describes a plastic-encapsulated pressure control valve of this type. This pressure control valve is to be further developed in this invention to be more robust and precise. Task:

[0005] Starting from a very robust and precise pressure control valve, as shown in publication DE 20 2010 017 04, the pressure control valve according to the invention is to be designed to be flange-mounted, have very low hysteresis and be more cost-effective to manufacture. Solution:

[0006] The problem is solved by the features of the independent patent claim. The dependent claims describe advantageous embodiments of the invention.

[0007] The problem is solved by an electrohydraulic pressure control valve comprising a valve body, an electromagnet with a pole core, a magnetic armature, and a sealing device. The valve body has a flange designed for mounting to an external device. Advantageously, the external device does not need to have a bore or recess for the pressure control valve; a flat surface to which the pressure control valve can be flanged is sufficient. This allows the pressure control valve to be connected to the device in a space-saving manner.

[0008] The pole core is located within the valve housing and rests, at least partially, directly against an inner wall of the valve housing. Furthermore, the pole core closes a flange-side opening of the valve housing. The pole core thus preferably serves for the fluidic connection of the pressure regulating valve to the device. The pole core incorporates at least one working port, one pressure port, and one tank port, which are provided for the fluidic connection to the device. Due to the pole core's location within the valve housing and its exposure to the flange side of the valve housing, simple connection to the device is possible, requiring only suitable mating ports. No special machining of the device, in particular the creation of recesses, is necessary. The connection of the various ports is primarily axial, i.e.,The fluid flow preferably enters and exits the pressure regulating valve in an axial direction. The axial direction is particularly coaxial with the central axis of the valve housing and / or pole core and / or magnetic armature and / or electromagnet.

[0009] The pole core also features several bores that fluidically connect the tank port, the pressure port, and the working port. At least one of these bores contains a valve slide, allowing the pressure port and the tank port to be selectively connected to, and disconnected from, the working port. This enables the adjustment of different fluid flow rates.

[0010] The magnetic armature is also arranged within the valve housing, and is movable by the electromagnet. In particular, the electromagnet is a proportional magnet. Thus, the electrohydraulic pressure control valve is preferably a proportionally acting electrohydraulic pressure control valve. The magnetic armature and the valve spool are coupled in their movement, allowing for the adjustment of different fluid flows through the valve by means of the electromagnet.

[0011] The sealing device is attached to the pole core and designed to fit against the device. The sealing device serves to seal the connections of the pressure port and / or tank port and / or working port to the device against each other and / or against the environment. Advantageously, at least one section of the sealing device, and in particular each section of the sealing device, has one side exposed to the pressure port, tank port, or working port, and an opposite side exposed to another of the ports or the environment.

[0012] The sealing device is also designed to seal a contact area between the valve housing and the pole piece. This prevents or at least hinders the ingress of fluid between the pole piece and the valve housing. In particular, this eliminates the need for special corrosion protection measures for the components inside the valve housing. As a result, the design of the pressure control valve is simple and its manufacture is cost-effective.

[0013] Preferably, the pole core has a chamfer or recess on an outer edge. This outer edge is preferably an area that abuts the valve housing. It is also preferred that the chamfer or recess faces the device. The recess or chamfer forms a groove bounded on one side by the pole core and on the other by the valve housing. The sealing device is at least partially arranged in this groove. This advantageously achieves the sealing effect described above. Furthermore, it prevents or at least hinders the slippage of the sealing device during operation of the pressure regulating valve. This ensures a permanent sealing effect.

[0014] The pole core is preferably manufactured in one piece. Since no special corrosion protection measures are necessary, as previously described, no additional element needs to be inserted between the pole core and the valve body. Instead, the pole core can preferably rest directly against the valve body. This simplifies both the manufacturing of the pole core, as it is a single piece, and the assembly of the pressure regulating valve, as only the pole core needs to be mounted without any additional element.

[0015] It is also preferred that the sealing device is formed in one piece. In particular, the sealing device is a flat gasket consisting of a single piece. This, in turn, simplifies the assembly of the pressure regulating valve.

[0016] In an advantageous embodiment, the pole core has a groove-shaped sealing guide area that extends annularly around the working port. This is particularly advantageously a groove. For this purpose, the pole core is preferably manufactured as a turned part, with the working port being located on the axis of rotation. The sealing device is at least partially arranged within the sealing guide area. This prevents or at least hinders slippage or displacement of the sealing device. Thus, the sealing device is held in its designated position, especially when different fluid pressures act on different sides of the sealing device. Since the working port can be selectively connected to the tank port and the pressure port, or to neither port, the pressures at the working port are constantly changing.The sealing guide area prevents or at least makes it more difficult for the sealing device to shift despite changing pressures.

[0017] The bores preferably have a first bore, a second bore, and a third bore. The first bore is designed to receive the valve spool and is fluid-connected to the working port. Particularly preferably, the first bore extends along a central axis of the pole core. The second bore is fluid-connected to the tank port, and the third bore is fluid-connected to the pressure port. By moving the valve spool, different connections between the bores can be established, thus creating different flow rates between the individual ports.

[0018] Particularly advantageous is the inclusion of a first recess and a second recess, separate from the first, in the first bore. This increases the diameter of the first bore at both the first and second recesses. The second bore extends into the first recess, while the third bore extends into the second recess. The second and third bores are thus preferably oriented at an angle to the first bore. In this way, the first, second, and third bores are connected to each other simply and reliably.

[0019] Furthermore, it is particularly advantageous that the second bore has a length between 9.0 mm and 15.0 mm, particularly 11.5 mm, and / or an angle between 10° and 30°, particularly 20°, relative to the first bore. The third bore particularly advantageously has a length between 5.0 mm and 11.0 mm, particularly 7.5 mm, and / or an angle between 20° and 40°, particularly 30°, relative to the first bore. Such a design allows for optimal fluid flow through the pressure control valve, thereby optimizing the pressure drop within the pressure control valve.

[0020] In an alternative advantageous embodiment, the bores have a fourth bore for connecting the first and second bores, and a fifth bore for connecting the first and third bores. The second and third bores are thus preferably oriented parallel to the first bore. Forming recesses as previously described is not necessary.

[0021] The fourth and fifth bores are advantageously oriented transversely, and in particular perpendicularly, to the first bore. The fourth and fifth bores are sealed on an outer surface of the pole core. This prevents unwanted fluid leakage from the fourth and fifth bores. The sealing of the fourth and fifth bores is advantageously achieved by a laser weld. In particular, a separate laser weld, advantageously circumferential, is provided for each bore. The respective laser weld also serves to connect the pole core to a pressure sleeve surrounding the pole core circumferentially. This connection simultaneously seals the pole core and the pressure sleeve, thus eliminating the need for an additional seal such as an O-ring.

[0022] The valve spool has, in particular, a first cross-section for establishing a fluid connection between the working port and the tank port or the pressure port. Furthermore, the valve spool has, in particular, a second cross-section for separating the fluid flow between the working port and the tank port or the pressure port. The first cross-section preferably has a bore and, in particular, forms a fluid-flowable connection cross-section between 2.5 mm² and 5.0 mm², preferably 3.2 mm². Fluid can flow through this connection cross-section between the working port and the tank port, as well as between the pressure port and the working port. By designing the connection cross-section as described above, a flow rate of 2 liters per minute at a pressure differential of 2.7 bar can be achieved. Thus, the first cross-section is optimized from a fluid flow perspective with respect to the fluid flow through the pressure regulating valve.The pole piece preferably has a length that is a maximum of 60% of the total length of the pole piece and magnetic armature. This optimizes the length of the magnetic armature, as its design allows it to capture an optimized amount of stray flux originating from the electromagnet's magnetic field. This, in turn, enables the generation of maximum magnetic force. The total length of the magnetic armature and pole piece is primarily limited by the valve housing.

[0023] It is also preferred that the magnetic armature and / or valve spool are movable along an axial direction. This axial direction is particularly coaxial with a central axis of the pressure regulating valve. The pole core preferably does not protrude beyond the flange with respect to the axial direction. Thus, the pole core does not protrude into the device when the pressure regulating valve is connected to it. This allows for a simple design of the device, so that no complex machining or shaping of the device is necessary for connecting the pressure regulating valve.

[0024] The pressure control valve is particularly suitable for regulating a pilot pressure for a downstream directional control valve or for an auxiliary task of the machine to be controlled, according to an electrical control signal.

[0025] The control signal is preferably in the form of a regulated electric current and is converted in an electromagnet, which is part of the pressure regulating valve, into a force which, due to the special design, but known design of the electromagnet, in particular due to the shape of the magnetic pole of this electromagnet, is advantageously proportional to the electric current, even with different strokes of the magnetic armature.

[0026] The force is transmitted from the magnetic armature to a valve spool, primarily by means of a plunger. At this valve spool, the force of the magnetic armature is compared with the hydraulic force resulting from the pressure on the end face of the valve spool connected to the working port and the size of this end face.

[0027] If the pressure at the valve's working port exceeds the force of the magnetic armature, the valve spool moves towards the electromagnet, opening a variable cross-section for fluid flow from the working port to the tank port. As a result, the pressure at the working port decreases. Conversely, if the force of the magnetic armature exceeds the pressure at the working port, the valve spool moves away from the electromagnet, opening a second variable cross-section for fluid flow from the pressure port to the working port. Consequently, the pressure at the working port increases. When the force of the magnetic armature and the pressure are in equilibrium, a spring returns the valve spool to a neutral position, preventing fluid flow to or from the working port.

[0028] The described control function occurs when sufficient supply pressure and a suitable flow rate of the hydraulic fluid are available at the pressure connection. It is also advantageous if the pressure at the tank connection is relatively low and the consumer connected to the working connection draws only a small flow rate.

[0029] The release of variable cross-sections for the fluid flows is preferably achieved by the interaction of internal control edges of the valve spool with external control edges in the magnetic pole surrounding the valve spool. Preferably, only one of the two variable cross-sections is released at any given time, but a design is also possible in which both variable cross-sections act simultaneously; this is achieved by the so-called overlap of the control edges.

[0030] The outer control edges are preferably formed by recesses or transverse bores in the magnetic pole, and these cavities are connected to the pressure port and the tank port via longitudinal bores. When recesses are used, the longitudinal bores are advantageously arranged at a shallow angle relative to the bore for the valve spool, so that the connections on the flange surface are sufficiently far apart.

[0031] In the flange surface of the pressure regulating valve to the upstream device, the working port, the pressure port, and the tank port are sealed to each other and to the environment. This is advantageously achieved by a common flat gasket with openings for the ports, or by at least three O-rings, which are chambered in a known manner because they are inserted into suitable circular grooves.

[0032] The pressure control valve according to the invention is very resistant because it has a magnetic housing, preferably made of deep-drawn iron, which also includes the valve part, and it operates very precisely in regulating the pressure because it has two variable cross-sections for adjusting the liquid flows.

[0033] The hysteresis of the pressure control valve is very low, particularly because the magnetic armature is guided very precisely relative to the magnetic pole by the valve spool. This is because the valve spool and the plunger supporting the magnetic armature are advantageously manufactured as a single piece, and the valve spool slides within the magnetic pole with very little play. Alternatively, a ball joint is provided. This common component is advantageously made of a material with very low magnetizability, such as brass or austenitic steel, to prevent a magnetic short circuit bridging the air gap.

[0034] Furthermore, the pressure regulating valve can be flanged because the valve part of the pressure regulating valve is completely enclosed by the solenoid housing of the proportional solenoid, and thus the flange of the solenoid housing limits the length of the entire device. A mounting hole in the device to which the pressure regulating valve is flanged is not required.

[0035] This results in a significant cost reduction for the system consisting of the pressure regulating valve and the higher-level device, because either an installation bore in the device or an additional flange-mountable control block with an installation bore can be dispensed with. Application:

[0036] Pressure control valves of the type described are used for electrohydraulic pilot control of proportional directional control valves and for controlling auxiliary functions in mobile hydraulics, for example in agricultural machinery, construction machinery, and forestry equipment. Applications for adjusting hydrostatic pumps are also known. Figures:

[0037] Further details, advantages and features of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawing. It shows: Fig. 1 shows the pressure control valve according to a first embodiment with recesses in the bore for guiding the valve spool, and Fig. 2 shows the pressure control valve according to a second embodiment with transverse bores.

[0038] The proportional electrohydraulic pressure control valve 1 is in Fig. 1as shown in a first embodiment and comprises a valve housing, an electromagnet 2 which converts an electric current into a proportional force, and a valve part 3 which converts said force into a controlled hydraulic pressure.

[0039] The electromagnet 2 consists of a coil, a yoke, and a pole piece 9, and is arranged within a valve housing 4 that serves as an iron return. A magnetic armature 20 is movable by the electromagnet 2.

[0040] The valve part 3 is also completely enclosed by the valve housing 4.

[0041] A flange 5 molded onto the magnet housing 4 connects the pressure control valve 1 to a higher-level device 6.

[0042] The valve part 3 includes a valve slide 8 movable in a first bore 15 of the pole core 9. The valve slide 8 is acted upon by pressure on its end face opposite the electromagnet 2 and by the force of the electromagnet 2. A first cross-section 11 of the valve slide 8 establishes a connection between a working port A formed on the pole core 9 and a tank port T formed on the pole core, and / or a connection between a pressure port P formed on the pole core 9 and the working port A. A second cross-section 12 of the valve slide separates the working port from the pressure port and / or the tank port.

[0043] In Fig. 1 Figure 1 shows a state in which a connection is made between tank port T and working port A, while the connection between pressure port and working port is disconnected.

[0044] The pole core 9 encloses the movable valve slide 8 and has all the fixed components of the valve part 3, namely the first bore 15 connected to the working port A, the external control edges for interaction with the first cross-section 11 and second cross-section 12, as well as a second bore 18 for connecting the tank port T to the first bore 15 and a third bore 19 for connecting the pressure port P to the first bore 15.

[0045] The magnetic armature 20 is connected to the valve slide 8 by means of a plunger or via a ball joint 26, wherein the plunger and the valve slide 8 are preferably made in one piece and the magnetic armature 20 is guided in particular by the valve slide 8.

[0046] The component that fulfills the functions of the plunger and the valve slide 8 is preferably made of brass or of an austenitic steel.

[0047] In the first embodiment, the cross-sections 11 and 12 of the valve slide 8 interact with a first recess 13 and a second recess 14 of the first bore 15 to release fluid flows from the working port A to the tank port T or from the pressure port P to the working port A.

[0048] The first bore 13 is connected to the tank connection T through the second bore 18 and the second bore (14) is connected to the pressure connection P through the third bore 19.

[0049] The magnetic armature 20 and the valve spool 8 are movable along an axial direction 100, which is oriented coaxially to a central axis of the pressure control valve 1. In the first embodiment, the first bore 15 extends along the axial direction 100, while the second bore 18 and the third bore 19 are angled relative to the first bore 15. The second bore has a length between 9.0 mm and 15.0 mm, in particular 11.5 mm. The third bore has a length between 5.0 mm and 11.0 mm, in particular 7.5 mm. The second bore 18 also has an angle between 10° and 30°, in particular 20°, relative to the first bore 15. The third bore has an angle between 20° and 40°, in particular 30°, relative to the first bore 15. The first cross-section 11 has a bore transverse to the axial direction 100 and forms a fluid-flowable connecting cross-section between 2.5 mm 2< and 5.0 mm 2< , preferably 3.2 mm 2< .Fluid can flow through the connection cross-section between working port A and tank port T, as well as between pressure port P and working port A. By designing the connection cross-section as described above, a flow rate of 2 liters per minute can be achieved at a pressure differential of 2.7 bar. This design ensures optimal fluid flow through the pressure regulating valve, minimizing the pressure drop within the valve.

[0050] The pole core 9 has a first length L1, and the magnetic armature 20 has a second length L2. The first length L1 comprises a maximum of 60% of the total length L1+L2 of the pole core 9 and magnetic armature 20. This second length L2 enables the magnetic armature 20 to capture a large amount of stray flux originating from the magnetic field of the electromagnet 2. This allows for the generation of maximum magnetic force.

[0051] Furthermore, a sealing device 7 is provided. The sealing device 7 is a one-piece seal, in particular a flat gasket, and fulfills several functions. On the one hand, the sealing device 7 is designed to be placed against the device 6 in order to seal the fluid connections of tank connection T, working connection A, and pressure connection P with the device 6 from each other and from the environment. In addition, the sealing device 7 serves to seal a contact area between pole core 9 and valve housing 4. For this purpose, the pole core 9 has a chamfer 22 or a recess that forms a groove 10. The groove 10 is bounded on one side by the pole core 9 and on the other side by the valve housing 4. The sealing device 7 is at least partially arranged in the groove 10 and thus seals the contact area between the pole core 9 and the valve housing 4.This prevents fluid from penetrating between the valve housing 4 and the pole core 9, thus eliminating the need for special corrosion protection measures within the valve housing 4. Furthermore, this method allows the pole core 9 to be formed in one piece and directly attached to the valve housing 4.

[0052] Furthermore, a groove-shaped sealing guide area 27 is provided around the working connection A, which serves to at least partially receive the sealing device 7. This makes it more difficult for the sealing device 7 to shift. This is particularly advantageous because the working connection A is constantly subjected to changing pressures.

[0053] The pole core 9 is also sealed against a surrounding pressure sleeve 28 by means of an additional seal 23. A spring 25 arranged between the pole core 9 and the magnetic armature 20 ensures that the magnetic armature 20 is returned to a starting position when the magnetic field from the electromagnet 2 is removed, in which the valve slide 8 connects the working port A to the tank port T.

[0054] In a second embodiment as in Fig. 2The pressure regulating valve 1 shown differs from the first embodiment only in the design of the pole core 9. In the second embodiment, in addition to the first bore 15, the second bore 18, and the third bore 19, a fourth bore 16 and a fifth bore 17 are provided. The first bore 15, the second bore 18, and the third bore 19 are preferably oriented parallel to each other and advantageously parallel to the axial direction 100. The fourth bore 16 serves to connect the first bore 15 and the second bore 18, and the fifth bore 17 serves to connect the first bore 15 and the third bore 19. The previously described first recess 13 and second recess 14 are not necessarily required. Preferably, the fourth bore 16 and the fifth bore 17 are oriented perpendicular to the first bore 15.

[0055] To prevent fluid from unintentionally escaping from the pole core 9, the fourth bore 16 and the fifth bore 17 are sealed on an outer surface of the pole core 9. This sealing is preferably achieved by a laser weld 24. Each laser weld 24 is preferably made circumferentially around the pole core 9 and welds the pole core 9 to the pressure sleeve 28. Thus, as an alternative to the representation in Figure 2 The additional seal 23 is omitted, since a sealing effect is already achieved by the respective laser weld 24.

[0056] In all cases, the pole core 9 does not protrude beyond the flange 5 in the axial direction 100. This allows the pressure regulating valve 1 to be directly attached to the device 6 without the need for special recesses for the pressure regulating valve on the device 6.

[0057] In addition to the foregoing written description of the invention, explicit reference is hereby made to the graphic representation of the invention in the following for its supplementary disclosure. Fig. 1 and 2 Reference made to. Reference symbol list

[0058] 1 Pressure regulating valve 2 Electromagnet 3 Valve part 4 Valve body 5 Flange 6 Device 7 Sealing device 8 Valve spool 9 Pole core 10 Groove 11 First variable cross-section 12 Second variable cross-section 13 First recess 14 Second recess 15 First bore 16 Fourth bore 17 Fifth bore 18 Second bore 19 Third bore 20 Magnetic armature 21 Valve body opening 22 Chamfer 23 Additional seal 24 Laser weld 25 Spring 26 Rod end 27 Seal guide area 28 Pressure sleeve A Working port P Pressure port T Tank port

Claims

1. Electrohydraulic pressure control valve (1), having - a valve housing (4) having a flange (5) which is designed to be flanged to an apparatus (6); - a solenoid (2) which is disposed within the valve housing (4) and has a pole core (9); ∘ wherein the pole core (9) is disposed within the valve housing (4) and at least in portions bears directly on an internal wall of the valve housing (4); ∘ wherein the pole core (9) closes a flange-proximal opening (21) of the valve housing (4); ∘ wherein formed in the pole core (9) are at least one working port (A), one pressure port (P) and one tank port (T) which are provided for fluidically connecting to the apparatus (6); ∘ wherein the pole core (9) has a plurality of bores (15, 16, 17, 18, 19) which fluidically connect the tank port (T), the pressure port (P) and the working port (A); and ∘ wherein a valve slide (8), by way of which the pressure port (P) and the tank port (T) are able to be selectively connected to the working port (A) and disconnected from the working port (A), is guided in at least one of the bores (15, 16, 17, 18, 19); - a solenoid armature (20) which is disposed within the valve housing (4) and movable by the solenoid (2), wherein the solenoid armature (20) for movement is operatively coupled to the valve slide (8); and - a sealing device (7) which ∘ is attached to the pole core (9) and designed to bear on the apparatus (6); and ∘ is designed to seal the connections between the pressure port (P) and / or the tank port (T) and / or the working port (A) and the apparatus (6) in relation to one another and / or in relation to the environment, characterized in that - the sealing device (7) is designed to seal a contact region between the valve housing (4) and the pole core (9) in such a way that any ingress of fluid between the pole core (9) and the valve housing (4) is prevented.

2. Pressure control valve (1) according to Claim 1, characterized in that the pole core (9) on an outer periphery has a bevel (22) or a clearance by way of which is formed a groove (10) that is delimited by the pole core (9) and the valve housing (4), wherein the sealing device (7) is at least partially disposed in the groove (10).

3. Pressure control valve (1) according to Claim 1 or 2, characterized in that the pole core (9) is of an integral design.

4. Pressure control valve (1) according to one of the preceding claims, characterized in that the sealing device (7) is of an integral design.

5. Pressure control valve (1) according to one of the preceding claims, characterized in that the pole core (9) has a groove-shaped seal-guiding region (27) which extends in an annular manner about the working port (A), wherein the sealing device (7) is a least partially disposed in the seal-guiding region (27).

6. Pressure control valve (1) according to one of the preceding claims, characterized in that the bores (15, 16, 17, 18, 19) have a first bore (15), a second bore (18) and a third bore (19), wherein the first bore (15) is designed to receive the valve slide (8) and is fluidically connected to the working port (A), wherein the second bore (18) is fluidically connected to the tank port (T), and wherein the third bore (19) is fluidically connected to the pressure port (P).

7. Pressure control valve (1) according to Claim 6, characterized in that a first recess (13) and a second recess (14), which is separate from the first recess (13), are formed on the first bore (15), wherein the second bore (18) extends into the first recess (13), wherein the third bore (19) extends into the second recess (14), and wherein preferably the second bore (18) and the third bore (19) are oriented obliquely in relation to the first bore (15).

8. Pressure control valve (1) according to Claim 7, characterized in that the second bore (18) has a length between 9.0 mm and 15.0 mm, and / or has an angle between 10° and 30° in relation to the first bore (15), and / or in that the third bore (19) has a length between 5.0 mm and 11.0 mm and / or an angle between 20° and 40° in relation to the first bore (15).

9. Pressure control valve (1) according to Claim 8, characterized in that the second bore (18) has a length of 11.5 mm and has an angle of 20° in relation to the first bore (15), and / or in that the third bore (19) has a length of 7.5 mm and an angle of 30° in relation to the first bore (15).

10. Pressure control valve (1) according to Claim 6, characterized in that the bores (15, 16, 17, 18, 19) have a fourth bore (16) for connecting the first bore (15) and the second bore (18), as well as a fifth bore (17) for connecting the first bore (15) and the third bore (19), wherein the second bore (18) and the third bore (19) are oriented parallel to the first bore (15).

11. Pressure control valve (1) according to Claim 10, characterized in that the fourth bore (16) and the fifth bore (17) are oriented transversely to the first bore (15), wherein the fourth bore (16) and he fifth bore (17) on an external side of the pole core (9) are closed by a laser-welded seam (24), and wherein closing the fourth bore (16) and the fifth bore (17) is performed by at least one laser-welded seam (24) which is designed for the materially integral connection between the pole core (9) and a pressure sleeve (28) which at least partially encloses the pole core (9).

12. Pressure control valve (1) according to one of the preceding claims, characterized in that the valve slide (8) has a first cross section (11) for establishing a fluidic connection between the working port (A) and the tank port (T) or the pressure port (P), as well as a second cross section (12) for fluidically disconnecting the working port (A) from the tank port (T) or from the pressure port (P), wherein the first cross section (12) forms a fluidically negotiable connecting cross section between 2.5 mm2 and 5.0 mm2.

13. Pressure control valve (1) according to Claim 12, characterized in that the first cross section (12) forms a fluidically negotiable connecting cross section of 3.2 mm2.

14. Pressure control valve (1) according to one of the preceding claims, characterized in that the pole core (9) has a length which is at most 60% of an overall length of the pole core (9) and the solenoid armature (20).

15. Pressure control valve (1) according to one of the preceding claims, characterized in that the solenoid armature (20) and / or the valve slide (8) are / is movable along an axial direction (100), wherein the pole core (9) does not project beyond the flange (5) in terms of the axial direction (100).