Hydraulic valve

Abstract

Hydraulic valve (1, 101), in particular load holding valve, with a valve housing (2, 102), a valve cone (3, 103), a spring housing (4, 104), a check valve (5, 105), a first hydraulic connection (6, 106) and a second hydraulic connection (7, 107), wherein the valve housing (2, 102) has a valve seat (8, 108), wherein the valve cone (3, 103) is movably arranged in the valve housing (2, 102) between a closed position (SS) and an open position (OS), wherein the valve cone (3, 103) rests against the valve seat (8, 108) in the closed position (SS) and blocks a first flow path between the first hydraulic port (6, 106) and the second hydraulic port (7, 107), wherein the valve cone (3, 103) is lifted from the valve seat (8, 108) in the open position (OS) and releases the first flow path from the first hydraulic port (6, 106) to the second hydraulic port (7, 107), wherein a spring element (9, 109) is arranged in the spring housing (4, 104), wherein the spring element (9, 109) biases the valve cone (3, 103) into the closed position (SS), and wherein the check valve (5, 105) is arranged in the valve cone (3, 103) and, when the second hydraulic port (7, 107) is pressurized, opens a second flow path from the second hydraulic port (7, 107) to the first hydraulic port (6, 106), characterized by the fact that The valve cone (3, 103) has a fluid guide (10, 110) passing through the valve cone (3, 103) in the direction of flow from the second hydraulic port (7, 107) to the first hydraulic port (6, 106) upstream of the check valve (5, 105), wherein the fluid guide (10, 110) is part of the first flow path when the valve cone (3, 103) is in the open position (OS).

Description

[0001] The present invention relates to a hydraulic valve, in particular a load-holding valve which is preferably designed as a load-holding valve cartridge.

[0002] Hydraulic valves designed as load-holding valves or load-holding valve cartridges are generally known from the prior art. They are used in hydraulic systems to prevent uncontrolled lowering, for example, in forklifts or lifting platforms. Such a hydraulic valve has a valve seat and a valve cone that rests against the valve seat without leakage. The valve cone is pre-tensioned with a force greater than the maximum possible load pressure. Adjustable spring systems are typically used for this purpose, housed in a spring casing with corresponding spring retainers. A hydraulic throttle or aperture is usually provided, which acts depending on the opening stroke to allow controlled lowering under load. Lowering is achieved by opening the valve cone of the load-holding valve, for example, by applying hydraulic actuation pressure to a control port.If the combined load pressure and control pressure exceed the preload force, the load-holding valve opens. The desired lowering speed is controlled by the control pressure. Furthermore, such valves typically have a check valve that bypasses the valve seat to allow lifting under load. Such load-holding valves are known, for example, from EP 0 902 194 A1, EP 1 063 431 A1, and DE 10 2019 218 401 B3.

[0003] German patent application DE 10 2019 218 401 B3 discloses a hydraulic valve comprising a valve body, a valve cone, a spring housing, a check valve, a first hydraulic port, and a second hydraulic port. The valve body has a valve seat, and the valve cone is movably arranged within the valve body between a closed position and an open position. In the closed position, the valve cone rests against the valve seat, and in the open position, the valve cone is lifted from the valve seat. In the closed position, the valve cone blocks a first flow path between the first hydraulic port and the second hydraulic port. In the open position, the valve cone opens the first flow path from the first hydraulic port to the second hydraulic port. A spring element is arranged in the spring housing, which biases the valve cone into the closed position.The check valve is located in the valve cone and, when the second hydraulic port is pressurized, opens a second flow path from the second hydraulic port to the first hydraulic port.

[0004] These hydraulic valves are typically screwed or fixed into a block and actuated in such a way that two hydraulic ports, connected to corresponding channels within the block, are linked to lower the load. The hydraulic fluid flows from the first hydraulic port, to which a hydraulic consumer such as a hydraulic cylinder is usually connected, past the valve cone (which is lifted from the valve seat) to the second hydraulic port, to which, for example, a spool or a changeover valve is connected. A disadvantage of this solution is that both channels must be provided within the block, which is undesirable in some applications, increases the manufacturing costs of the block, and also requires additional installation space.

[0005] Solutions have therefore emerged that incorporate a hydraulic connection on the spring housing of the hydraulic valve. Such solutions are more cost-effective to manufacture, save installation space, and allow for use in a wide variety of applications.

[0006] With an open valve cone, the hydraulic fluid flows outwards at the valve seat towards the spring housing. At the connection point of the spring housing, the hydraulic fluid is deflected and flows over the spring retainer into the spring housing. Due to these deflections, different cross-sectional areas result, leading to overall less favorable flow resistances. This results in an increased overall system energy consumption and also raises the risk of particle and contaminant deposits.

[0007] Furthermore, a hydraulic connection on the spring housing poses the risk that a connected line, for example when used in a forklift or crane arm, could become entangled or caught during operation, damaging or even completely breaking off the spring housing. This would cause the spring element to lose its preload, and the actual control parameter—namely, the opening of the valve cone, which is defined by the spring preload—would suddenly drop to "0" (zero). Consequently, any lifted load could sag uncontrollably. This can lead to serious or even fatal accidents.

[0008] It is therefore an object of the present invention to provide a hydraulic valve, in particular designed as a load-holding valve, which, despite its simple design, exhibits favorable flow and cross-sectional characteristics. Furthermore, it is an object of the present invention to provide a hydraulic valve, in particular designed as a load-holding valve, in which the risk of damage to the spring housing and the resulting hazards is minimized.

[0009] The problem is solved with a hydraulic valve according to claim 1 and with a hydraulic valve according to claim 3. Advantageous embodiments are described in the dependent claims.

[0010] According to the invention, a hydraulic valve is proposed comprising a valve housing, a valve cone, a spring housing, a check valve, a first hydraulic port, and a second hydraulic port. The hydraulic valve is, in particular, a load-holding valve and preferably a load-holding valve cartridge for screwing into a block. The valve housing has a valve seat, wherein the valve cone is movably arranged within the valve housing between a closed position and an open position. In the closed position, the valve cone rests against the valve seat, and in the open position, the valve cone is lifted from the valve seat. In the closed position, the valve cone blocks a first flow path between the first hydraulic port and the second hydraulic port. In the open position, the valve cone releases the first flow path from the first hydraulic port to the second hydraulic port.A spring element is arranged in the spring housing, which biases the valve cone into the closed position. The check valve is arranged in the valve cone and, when the second hydraulic port is pressurized, opens a second flow path from the second hydraulic port to the first hydraulic port. According to the invention, the valve cone, viewed upstream of the check valve in the flow direction from the second hydraulic port to the first hydraulic port, has a fluid guide that passes through the valve cone, wherein the fluid guide is part of the first flow path when the valve cone is in the open position.

[0011] In other words, when the valve cone is open, the hydraulic fluid flows along the first flow path, with the fluid guide forming part of this first flow path. The hydraulic fluid then flows through the fluid guide into the valve cone and from there to the second hydraulic port. Thus, the hydraulic fluid is not guided past the outer surface of the valve cone to the second hydraulic port, but rather is directed into the interior of the valve cone via the fluid guide, from where it flows to the second hydraulic port. This largely avoids unfavorable deflections and cross-sectional changes, preventing any undesirable increase in flow resistance. Consequently, the accumulation of dirt and other contaminants is also prevented. This results in a longer service life and a favorable overall system energy balance.Alternatively, it can be advantageous if the fluid path is part of the second flow path and offers favorable flow conditions when the load is lifted. This is particularly beneficial if the second hydraulic connection is also provided on the valve body.

[0012] Furthermore, this also increases the overall stability of the component. This is because the fluid guide is located in a section of the valve cone where no tensile forces are transmitted. Only the preload force of the spring element has to be absorbed in this area.

[0013] Preferably, the spring housing has a second hydraulic connection. This second hydraulic connection can be connected, for example, to a pressure source, a spool valve, or a changeover valve. This allows for a more cost-effective design of the hydraulic valve overall.

[0014] According to the invention, a hydraulic valve is further proposed, comprising a valve housing, a valve cone, a spring housing, a check valve, a first hydraulic port, and a second hydraulic port. The hydraulic valve is, in particular, a load-holding valve and preferably a load-holding valve cartridge for screwing into a block. The valve housing has a valve seat, wherein the valve cone is movably arranged within the valve housing between a closed position and an open position. In the closed position, the valve cone rests against the valve seat, and in the open position, the valve cone is lifted from the valve seat. In the closed position, the valve cone blocks a first flow path between the first hydraulic port and the second hydraulic port. In the open position, the valve cone releases the first flow path from the first hydraulic port to the second hydraulic port.A spring element is arranged in the spring housing, which biases the valve cone into the closed position. The check valve is located in the valve cone and, when the second hydraulic port is pressurized, opens a second flow path from the second hydraulic port to the first hydraulic port. The spring housing has the second hydraulic port, an external thread for screwing the hydraulic valve into a block, and a sealing element arranged on the outer circumference of the spring housing. According to the invention, the sealing element is arranged axially between the external thread and the valve housing. In other words, the sealing element is positioned between the external thread and the valve housing such that the external thread lies outside the sealing element in the direction of the second hydraulic port. The external thread is therefore dry and not in the area of ​​the hydraulic fluid.

[0015] A potential weak point in a spring housing is typically the area of ​​the sealing element, as this is where the cross-section of the spring housing is reduced or smallest. The arrangement of the sealing element according to the invention ensures that the area of ​​the sealing element is subject primarily to compressive loads and virtually free of tensile loads. Potential tensile loads, such as those caused by a line that has become stuck at the second hydraulic connection, are absorbed via the external thread and not in the area of ​​the sealing element, where the cross-section of the spring housing is typically smallest. Therefore, while the line at the second hydraulic connection might break off and cause a malfunction of the hydraulic valve or hydraulic line, the preload applied by the spring element is not lost, and a sudden drop of the actual control variable to "0" is prevented.This eliminates the risk of an uncontrolled sagging of a potentially lifted load.

[0016] It is conceivable that the sealing element is received in a circumferential groove on the outer circumference of the spring housing. The sealing element can, in particular, be a sealing ring, for example an O-ring.

[0017] Advantageously, the valve cone has an axially extending receiving chamber, wherein the fluid guide comprises at least one bore extending from an outer surface of the valve cone to the receiving chamber. In this context, it is advantageous if the fluid guide comprises a plurality of bores. The hydraulic fluid can flow through the bores into the receiving chamber and then to the second hydraulic port with virtually no flow resistance.

[0018] The bores can be arranged at regular intervals or in groups. Grouping the bores has the advantage that they are only drilled into the valve cone where the most hydraulic fluid flows. This reduces the manufacturing costs of the valve cone compared to regularly spaced bores.

[0019] It is advantageous if the check valve is integrated into the receiving chamber. This allows for a particularly space-saving design of the hydraulic valve and especially the valve cone.

[0020] Advantageously, the valve housing includes a fluid chamber, the fluid chamber being part of the first flow path, and the fluid guide opening into the fluid chamber at least when the valve cone is open. Preferably, the fluid guide also opens into the fluid chamber when the valve cone is closed. In the open position of the valve cone, the hydraulic fluid thus flows past the valve seat into the fluid chamber and from there, via the fluid guide, into the interior of the valve cone and subsequently to the second hydraulic port. This results in overall favorable flow and cross-sectional characteristics.

[0021] It is advantageous if the valve housing has an axial bore with an inner circumferential surface for receiving the valve cone, wherein the fluid chamber is formed by a recess on the inner circumferential surface of the axial bore that is at least partially circumferential. Preferably, the recess is completely circumferential. It should be noted that an axial bore does not necessarily have to be one that completely passes through the valve cone. Rather, the axial bore can also be one that only partially passes through the valve cone.

[0022] It is advantageous if the valve cone has a spring housing end facing the spring housing, with the valve cone being guided between the spring housing end and the fluid guide on the valve housing. In other words, the valve cone is guided in the valve housing at its axial end facing the spring housing, for example, in the manner of a slide fit. This ensures particularly good axial guidance during the movement of the valve cone.

[0023] Advantageously, the hydraulic valve has a spring retainer arranged in the spring housing with an axial passage. The valve cone preferably rests against the spring retainer, so that the preload force of the spring element is transmitted to the valve cone via the spring retainer. The axial passage is preferably dimensioned relatively large, so that the hydraulic fluid can flow largely unimpeded from the first hydraulic port to the second hydraulic port in this area.

[0024] It is advantageous for the hydraulic valve to have a third hydraulic port, allowing a control pressure to be applied to this port to move the valve cone into the open position against the force of the spring element. For this purpose, the hydraulic valve preferably has a control piston acting on the valve cone, which can be pressurized via the third hydraulic port. The control piston can be formed integrally with the valve cone or separately. This allows the hydraulic valve to be actuated by a corresponding control pressure as needed, enabling hydraulic fluid to flow in a controlled manner from the first to the second hydraulic port. Of course, it is also conceivable that the hydraulic valve could alternatively or additionally be actuated electromagnetically or manually.

[0025] The invention will now be explained in more detail with reference to exemplary embodiments shown in the figures. The figures schematically illustrate: Fig. 1 a section through a hydraulic valve according to a first embodiment, wherein the valve cone is in the closed position and the check valve is open; Fig. 2 a detailed view of the in Fig. 1 hydraulic valve shown; Fig. 3 the hydraulic valve according to Fig. 1, wherein the valve cone is in the open position and the check valve is closed; Fig. 4 a detailed view of the in Fig. 3 hydraulic valves shown; and Fig. 5 a section through a hydraulic valve according to a second embodiment.

[0026] In the Fig. 1, Fig. 2, Fig. 3 to Fig. Figure 4 shows a hydraulic valve 1 designed as a load-holding valve according to a first embodiment of the present invention. As shown, the load-holding valve 1 is designed as a load-holding valve cartridge which is screwed into a block B. Such a load-holding valve cartridge 1 is used, for example, to control a hydraulic cylinder or other hydraulic consumer against a load, to lower it under load according to a predetermined flow characteristic (pressure differential across the load-holding valve 1 versus the flow rate) with a control pressure and a predetermined control behavior, and to keep the load leak-free in the unactuated state.

[0027] For this purpose, the load-holding valve cartridge 1 has a valve housing 2 with an axially movable valve cone 3 therein, a first hydraulic port 6, and a second hydraulic port 7. Furthermore, the load-holding valve cartridge 1 has a spring housing 4 with a spring element 9 arranged therein. The spring element 9 is supported on one side by a first spring plate 18 which is axially movable within the spring housing 3. On the other side, the spring element 9 is supported by a second spring plate 22 which is fixed within the spring housing. The preload of the spring element 9 can be adjusted by moving the second spring plate 22 along the spring housing 4 in a known manner by screwing it in and out. The preload force of the spring element 9 is transmitted via the first spring plate 18 to a spring housing end 17 of the valve cone 3, so that the latter is drawn into the Fig. 1. The closed position SS shown is pre-tensioned.

[0028] The spring housing 4 has an external thread 23 for screwing the spring housing 4 into the block B. A sealing element 24 is provided to prevent high-pressure hydraulic fluid from escaping along the external thread 23. As shown in particular in Fig. 2 and Fig. As shown in Figure 4, the sealing element 24 is designed as a sealing ring which is received in a corresponding receiving groove 30 on the outer circumference of the spring housing 4. In this embodiment, the sealing ring 24 is an O-ring. Viewed axially from the second hydraulic connection 7 to the valve housing 2, the sealing element 24 is arranged after the external thread 23, i.e., when the load-holding valve cartridge 1 is screwed into block B, it is located between the external thread 23 and the valve housing 2. This ensures that the structurally weaker area of ​​the spring housing 4, created by the receiving groove 30, is largely not subjected to tensile stress even in the event of an unintended external force acting on the spring housing 4, thus eliminating the risk of the spring housing 4 breaking off at this point.

[0029] As in Fig. 1 and Fig. As shown in Figure 3, the second hydraulic port 7 is located at the axial end of the spring housing 4 furthest from the valve cone 3. The first hydraulic port 6 is connected in the conventional manner to a channel in block B. A hydraulic consumer, for example a hydraulic cylinder, which can be extended and retracted against a load, is typically connected to the first hydraulic port 6. A pressure source, a spool valve, or a changeover valve, for example, is connected to the second hydraulic port 7 in the conventional manner. In the Fig. In the closed position SS shown in Figure 1, the load-holding valve cartridge 1 is not actuated and a load applied via the hydraulic cylinder connected to the first hydraulic port 6 is kept free of leakage oil, since the valve cone 3 rests on a valve seat 8 formed on the valve housing 2 and blocks a first flow path between the first hydraulic port 6 and the second hydraulic port 7, as will be described in more detail below.

[0030] To lift a load via the hydraulic cylinder connected to the first hydraulic port 6, the first hydraulic port 6 must be pressurized. For this purpose, the load-holding valve cartridge 1 has a check valve 5 bypassing the valve seat 8 to allow a second flow path from the second hydraulic port 7 to the first hydraulic port 6.

[0031] The check valve 5 is received in an axially extending receiving chamber 11 of the valve cone. As shown, the check valve 5 is designed as a ball check valve and comprises a ball 26 which, in the closed position of the check valve 5, rests against a check valve seat 27 formed in the receiving chamber 11 of the valve cone 3, see also Fig. 3. The ball 26 rests against a cup 28 in which a spring element 29 is housed. The spring element 29 generates a relatively small force, which is transmitted via the cup 28 to the ball 26 and ultimately serves only to hold the ball 26 against the check valve seat 27 in the depressurized state. When the second hydraulic port 7 is pressurized, the ball 26 is axially displaced against the closing force of the spring element 29 due to the pressure then present in the receiving chamber 11, so that the ball 26 is lifted from the check valve seat 27, cf. Fig. 1 and Fig. 2. The hydraulic fluid can then flow from the receiving chamber 11 to the first hydraulic connection 6 along the second flow path, and the hydraulic cylinder connected there extends. The load is lifted.

[0032] In a state in which a load is kept free of leakage oil, the load pressure applied via the first hydraulic connection 6 also acts on the ball 26, so that it rests against the check valve seat 27.

[0033] To lower the load in a controlled manner, the first hydraulic connection 6 must be connected to the second hydraulic connection 7. For this purpose, the valve cone 3 is removed from the Fig. 1 shown blocking position SS in the in Fig. 3 shown in the open position OS is moved. For this purpose, the valve cone is lifted from the valve seat 8 formed on the valve housing 2 against the preload force of the spring element 9 and the first flow path between the first hydraulic port 6 and the second hydraulic port 7 is opened in order to lower the load in a controlled manner.

[0034] To move the valve cone 3, the valve housing 2 in this embodiment has a third hydraulic port 20 through which a control pressure can be applied. The control pressure applied to the third hydraulic port 20 acts on a control piston 21 of the load-holding valve cartridge 1. In this embodiment, the control piston 21 is formed integrally with the valve cone 3, so that pressurizing the third hydraulic port 20 with a sufficiently high control pressure (i.e., that the total pressure of the control pressure and the load pressure exceeds the preload force of the spring element 9) moves the control piston 21 together with the valve cone 3 axially towards the spring housing 4, so that the valve cone 3 is lifted from the valve seat 8.

[0035] In the open position OS of the valve cone 3, i.e., when the third hydraulic port 20 is pressurized, hydraulic fluid can flow from the first hydraulic port 6 to the second hydraulic port 7 along the first flow path. Here, the hydraulic fluid enters an axial bore 15 of the valve housing 2 via the first hydraulic port 6 and flows past the valve seat 8 into a fluid chamber 14. In this embodiment, the fluid chamber 14 is formed as a circumferential groove on an inner circumferential surface 16 of the axial bore 15. The valve cone 3 has a fluid guide 10 with a plurality of bores 13 that penetrate the valve cone 3 by extending from the outer surface 12 of the valve cone 3 into the receiving chamber 11. As shown, the fluid guide 10 is located upstream of the check valve 5 in the flow direction from the second hydraulic port 7 to the first hydraulic port 6.In this embodiment, the bores 13 are grouped together and positioned on the valve cone 3 such that they connect the areas of the fluid chamber 14 most exposed to the flow with the receiving chamber 11. The hydraulic fluid then flows from the fluid chamber 14 through the bores 13 of the fluid guide 10 into the receiving chamber 11 and from there towards the second hydraulic connection 7. To ensure the most unimpeded flow possible, the first spring plate 18 has a relatively large axial passage 19.

[0036] To achieve particularly good guidance of the valve cone 3, the valve cone 3 is guided between the spring housing end 17 and the fluid guide 10 in the valve housing 2. As shown in particular in Fig. As shown in Figure 2 and Figure 4, the valve cone 3 is guided on a corresponding guide surface which, viewed from the first hydraulic connection 6 to the fluid chamber 14, is formed on the inner circumferential surface 16 of the axial bore 15 after the fluid chamber 14.

[0037] In Fig.Figure 5 shows a second embodiment of a hydraulic valve 101 according to the invention, designed as a load-holding valve cartridge. The hydraulic valve 101 according to the second embodiment differs from the hydraulic valve 1 described above by the arrangement of the second hydraulic port 107. As shown, the second hydraulic port 107 is not arranged on the spring housing 104, but on the valve housing 102. The second hydraulic port 107 is connected to a corresponding channel in block B. In this embodiment, the fluid guide 110 of the valve cone 103 comprises two bores 113, which extend from the outer surface 112 of the valve cone 103 into the receiving chamber 111 of the valve cone 103.

[0038] To lift the load using the hydraulic cylinder connected to the first hydraulic port 106, the second hydraulic port 107 is pressurized. The hydraulic fluid then flows, at least partially, through the bores 113 of the fluid guide 110 into the receiving chamber 111 and opens the check valve 105. The hydraulic fluid then flows directly to the first hydraulic port 106 and the load is lifted.

[0039] To lower the load, the valve cone 103 is moved in a controlled manner against the preload force of the spring element 109 into the open position, so that the valve cone 103 lifts off the valve seat 108. Hydraulic fluid can then flow from the first hydraulic port 106 inside the valve housing 102 along the valve cone 103 to the second hydraulic port 107.

[0040] It should be noted that the foregoing embodiments are described for a hydraulic valve designed as a load-holding cartridge. However, the advantages of the invention are also applicable to other types of hydraulic valves, for example, pressure relief valves, check valves, load-holding valves not designed as cartridges, or shut-off valves. Reference symbol list 1, 101 hydraulic valve / load holding valve / load holding valve cartridge 2, 102 Valve housings 3, 103 valve cones 4,104 spring housings 5, 105 Check valve 6, 106 first hydraulic connection 7, 107 second hydraulic connection 8, 108 Valve seat 9, 109 Spring element 10, 110 Fluid guidance 11, 111 Reception Room 12, 112 Outer surface of the valve cone 13, 113 bore 14 Fluid chamber 15 Axial bore 16 inner circumferential surface of the axial bore 17 Spring housing end 18 first spring plate 19 axial passage 20 third hydraulic connection 21 Control pistons 22 second spring plate 23 external threads 24 sealing element 26 balls 27 Check valve seat 28 pots 29 Spring element 30 recordings Block B OS disclosure SS Blocking Position

Claims

[1] Hydraulic valve (1, 101), in particular load holding valve, with a valve body (2, 102), a valve cone (3, 103), a spring housing (4, 104), a check valve (5, 105), a first hydraulic connection (6, 106) and a second hydraulic connection (7, 107), wherein the valve housing (2, 102) has a valve seat (8, 108), wherein the valve cone (3, 103) is movably arranged in the valve housing (2, 102) between a closed position (SS) and an open position (OS), wherein the valve cone (3, 103) rests against the valve seat (8, 108) in the closed position (SS) and blocks a first flow path between the first hydraulic port (6, 106) and the second hydraulic port (7, 107), wherein the valve cone (3, 103) is lifted from the valve seat (8, 108) in the open position (OS) and releases the first flow path from the first hydraulic port (6, 106) to the second hydraulic port (7, 107), wherein a spring element (9, 109) is arranged in the spring housing (4, 104), wherein the spring element (9, 109) biases the valve cone (3, 103) into the closed position (SS), and wherein the check valve (5, 105) is arranged in the valve cone (3, 103) and, when the second hydraulic port (7, 107) is pressurized, opens a second flow path from the second hydraulic port (7, 107) to the first hydraulic port (6, 106), characterized by , that The valve cone (3, 103) has a fluid guide (10, 110) passing through the valve cone (3, 103) in the direction of flow from the second hydraulic port (7, 107) to the first hydraulic port (6, 106) upstream of the check valve (5, 105), wherein the fluid guide (10, 110) is part of the first flow path when the valve cone (3, 103) is in the open position (OS). [2] Hydraulic valve (1) according to claim 1, characterized by , that the spring housing (4) has the second hydraulic connection (7). [3] Hydraulic valve (1), in particular load holding valve, comprising a valve body (2), a valve cone (3), a spring housing (4), a check valve (5), a first hydraulic port (6) and a second hydraulic port (7), wherein the valve housing (2) has a valve seat (8), wherein the valve cone (3) is movably arranged in the valve housing (2) between a closed position (SS) and an open position (OS), wherein the valve cone (3) rests against the valve seat (8) in the closed position (SS) and blocks a first flow path between the first hydraulic port (6) and the second hydraulic port (7), wherein the valve cone (3) is lifted from the valve seat (8) in the open position (OS) and releases the first flow path from the first hydraulic port (6) to the second hydraulic port (7), wherein a spring element (9) is arranged in the spring housing (4), wherein the spring element (9) biases the valve cone (3) into the closed position (SS), wherein the check valve (5) is arranged in the valve cone (3) and, when the second hydraulic port (7) is pressurized, opens a second flow path from the second hydraulic port (7) to the first hydraulic port (6), wherein the spring housing (4) has the second hydraulic connection (7), an external thread (23) for screwing the hydraulic valve (1) into a block (B) and a sealing element (24) arranged on the outer circumference of the spring housing (4), characterized by , that the sealing element (24) is arranged in the axial direction between the external thread (23) and the valve housing (2). [4] Hydraulic valve (1) according to claim 3, characterized by , that the valve cone (3) has a fluid guide (10) passing through the valve cone (3) upstream of the check valve (5) in the direction of flow from the second hydraulic port (7) to the first hydraulic port (6), wherein the fluid guide (10) is part of the first and / or the second flow path. [5] Hydraulic valve (1, 110) according to claim 1, 2 or 4, characterized by, that the valve cone (3, 103) has an axially extending receiving space (11, 111), wherein the fluid guide (10, 110) comprises at least one bore (13, 113) extending from an outer surface (12, 112) of the valve cone (3, 103) to the receiving space (11, 111), wherein the fluid guide (10, 110) preferably has a plurality of bores (13, 113). [6] Hydraulic valve (1, 110) according to claim 5, characterized by , that the check valve (5, 105) is received in the receiving chamber (11, 111). [7] Hydraulic valve (1) according to one of claims 1, 2, 4, 5 or 6, characterized by , that the valve housing (2) includes a fluid chamber (14), wherein the fluid chamber (14) is part of the first flow path, and the fluid guide (10) opens into the fluid chamber (14) at least in the open position (OS) of the valve cone (3). [8] Hydraulic valve (1) according to claim 7, characterized by, that the valve housing (2) has an axial bore (15) with an inner circumferential surface (16) for receiving the valve cone (3), wherein the fluid chamber (14) is formed by a recess at least partially circumferential on the inner circumferential surface (16) of the axial bore (15). [9] Hydraulic valve (1) according to one of claims 1, 2, 4, 5, 6 or 7, characterized by , that the valve cone (3) has a spring housing end (17) facing the spring housing (4), wherein the valve cone (3) is guided between the spring housing end (17) and the fluid guide (10) on the valve housing (2). [10] Hydraulic valve (1) according to any of the preceding claims, characterized by , that the hydraulic valve (1) has a spring plate (18) arranged in the spring housing (4) with an axial passage (19), wherein the valve cone (3) rests against the spring plate (18). [11] Hydraulic valve (1) according to any of the preceding claims, characterized bythat the hydraulic valve (1) has a third hydraulic port (20), wherein a control pressure can be applied to the third hydraulic port (20) to move the valve cone (3) against a force of the spring element (9) into the open position (OS), wherein the hydraulic valve (1) preferably has a control piston (21) acting on the valve cone (3), wherein the control piston (21) can be pressurized via the third hydraulic port (20).

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