Zero leakage hydraulic directional valve and hydraulic station

Abstract

This invention belongs to the technical field of split-type directional valves and discloses a cone-valve type zero-leakage hydraulic directional valve and a hydraulic station. The cone-valve type zero-leakage hydraulic directional valve includes a valve body assembly, a valve core assembly, and a spring. During the leakage test of the hydraulic directional valve, the valve core assembly and the valve sleeve form a line seal. The valve core assembly and the valve sleeve are separated into a first annular cavity and a second annular cavity. Hydraulic oil is introduced through a second opening, and a third opening remains closed. The hydraulic oil fills the second annular cavity and further fills the first annular cavity. When the first annular cavity and the second annular cavity are filled, the hydraulic oil generates an axial force on the valve core assembly from the valve seat to the valve sleeve. Combined with the same-direction force applied by the spring to the valve core assembly, the line seal between the valve core assembly and the valve sleeve is ensured, the leakage of hydraulic oil between the valve core assembly and the valve sleeve is reduced, and the reliability of the hydraulic directional valve is improved.

Description

Technical Field

[0001] This invention relates to the field of split-type directional valve technology, and more particularly to a cone valve type zero-leakage hydraulic directional valve and hydraulic power unit. Background Technology

[0002] Before a hydraulic directional valve is put into production, its performance must be tested. The valve core of the directional valve is a one-piece structure. The original valve core structure only allows the valve core to be assembled unidirectionally from the valve port of the valve sleeve, so that there is no pressure difference on both sides of the valve core to make the valve core tend to be closed. In order for the valve core to be able to close reliably again after reciprocating left and right, the valve core and valve sleeve must ensure strict requirements for cylindricity, concentricity and roughness in processing. At the same time, the surface sealing gap between the valve core and the valve sleeve must also be strictly guaranteed. Moreover, since the valve core and valve sleeve are sealed by a conical valve line, there are extremely strict processing requirements at the conical valve line of the valve sleeve. This makes there is a risk of leakage between the valve core and valve sleeve of the hydraulic directional valve, which in turn makes the yield of the hydraulic directional valve low.

[0003] In related technologies, a directional valve is provided to solve the leakage problem between the valve core and the valve sleeve. The valve core adopts the structure of a spool valve, and the flow area gradually changes with the displacement direction of the valve core. The valve core and the valve sleeve form a cone valve line seal. However, the sealing performance of the line seal is poor, resulting in excessive leakage between the valve core and the valve sleeve of the directional valve, which reduces the reliability of the directional valve.

[0004] Therefore, there is an urgent need for a cone valve type zero-leakage hydraulic directional valve to solve the above problems. Summary of the Invention

[0005] One objective of this invention is to provide a cone-valve type zero-leakage hydraulic directional valve. This ensures a line seal between the valve core assembly and the valve sleeve, reduces hydraulic oil leakage between the valve core assembly and the valve sleeve, and improves the reliability of the hydraulic directional valve.

[0006] The second objective of this invention is to provide a hydraulic power unit that, by applying the aforementioned cone valve type zero-leakage hydraulic directional valve, can ensure the consistency of the oil circuit connection sequence of the hydraulic power unit, while also ensuring the stability of the hydraulic power unit.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] Cone valve type zero-leakage hydraulic directional valve, including:

[0009] A valve body assembly includes a valve seat and a valve sleeve connected to each other. The valve seat has a first opening. Along the direction from the valve seat to the valve sleeve, the valve sleeve has a second opening and a third opening in sequence. The inner diameter of the valve sleeve gradually increases from the first inner diameter to the second inner diameter. The second opening can communicate with the first opening and the second opening can communicate with the third opening.

[0010] A valve core assembly is inserted into the valve body assembly. The outer diameter of the valve core assembly located within the valve sleeve is the same as the second inner diameter, and the valve core assembly located within the valve seat can form a line seal with the valve sleeve. The valve core assembly has a leak detection state. When the valve core assembly is in the leak detection state, the valve core assembly forms a line seal with the valve sleeve, and the third opening is closed. Along the direction from the valve seat to the valve sleeve, the valve core assembly and the inner wall of the valve sleeve form a communicating first and second annular cavities. The second opening communicates with the second annular cavity and is supplied with hydraulic oil. When the hydraulic oil fills the first and second annular cavities, the valve core assembly is subjected to a force from the valve seat to the valve sleeve to ensure that the valve core assembly maintains a line seal with the valve sleeve, thereby preventing the second opening from communicating with the first opening.

[0011] A spring is disposed inside the valve seat, with one end abutting against the valve seat and the other end abutting against the valve core assembly. When the valve core assembly is in a leak detection state, the spring exerts a force on the valve core assembly from the valve seat to the valve sleeve.

[0012] Preferably, the valve core assembly includes:

[0013] A slide valve is disposed within the valve sleeve. The outer diameter of the slide valve is the same as the second inner diameter. Along the direction from the valve seat to the valve sleeve, the slide valve sequentially includes a first valve section, a second valve section, a third valve section, and a fourth valve section. The outer diameters of the second valve section and the fourth valve section are both the same as the second inner diameter. When the valve core assembly is in a leak detection state, the outer walls of the second valve section, the third valve section, the fourth valve section, and the inner wall of the valve sleeve form a second surrounding cavity. Along the direction from the valve seat to the valve sleeve, the cross-sectional areas at both ends of the second surrounding cavity are the same.

[0014] A cone valve is connected to the first valve section, and a portion of the cone valve is disposed within the valve seat. Along the direction from the valve seat to the valve sleeve, the cone surface of the cone valve faces the valve sleeve. When the valve core assembly is in a leak-testing state, the cone valve and the valve sleeve form a line seal. The cone surface of the cone valve, the outer wall of the first valve section, the outer wall of the second valve section, and the inner wall of the valve sleeve enclose a first annular cavity. Along the direction from the valve seat to the valve sleeve, the difference in cross-sectional area between the two ends of the first annular cavity is equal to the difference in area between the second inner diameter and the first inner diameter. When the hydraulic oil fills the first annular cavity and the second annular cavity, the force direction of the spool valve is from the valve seat to the valve sleeve.

[0015] Preferably, along the direction from the valve sleeve to the valve seat, the spool valve further includes a fifth valve section connected to the first valve section, the cone valve is sleeved on the fifth valve section and abuts against the end face of the first valve section, the outer wall of the fifth valve section is recessed with a snap-fit ​​groove, and the cone valve type zero-leakage hydraulic directional valve further includes:

[0016] A retaining ring is engaged in the retaining groove and abuts against the end face of the cone valve opposite to the first valve section.

[0017] Preferably, the cone valve type zero-leakage hydraulic directional valve further includes:

[0018] A sealing ring is provided, wherein the inner wall of the cone valve is recessed with a sealing groove or the outer wall of the fifth valve section is recessed with the sealing groove, and the sealing ring is housed within the sealing groove.

[0019] Preferably, the cone valve includes:

[0020] A conical sealing portion, wherein the conical sealing portion is provided with the conical surface;

[0021] The abutting part is integrally formed and connected with the cone sealing part, and the abutting part extends along the direction from the valve sleeve to the valve seat. The spring is sleeved on the abutting part and abuts against the cone sealing part.

[0022] Preferably, the outer wall of the second valve section is recessed with a buffer groove, and the buffer groove extends along the axial direction of the slide valve.

[0023] Preferably, multiple buffer grooves are provided, and the multiple buffer grooves are arranged at intervals along the circumferential direction of the slide valve.

[0024] Preferably, the outer wall of the second valve section is further recessed with a pilot groove, which is connected to the buffer groove, and the recessed depth of the pilot groove is less than the depth of the buffer groove.

[0025] The hydraulic power unit includes an integrated block and a cone-type zero-leakage hydraulic directional valve as described above, the cone-type zero-leakage hydraulic directional valve being disposed on the integrated block.

[0026] Preferably, the integrated block has a hydraulic oil hole, and the cone valve type zero-leakage hydraulic directional valve includes a valve seat and a valve sleeve. The valve sleeve is located inside the hydraulic oil hole, the valve seat is threadedly connected to the hydraulic oil hole, and the valve seat abuts against the valve sleeve.

[0027] The beneficial effects of this invention are:

[0028] This invention provides a cone-type zero-leakage hydraulic directional valve, comprising a valve body assembly, a valve core assembly, and a spring. The valve body assembly includes a valve seat and a valve sleeve connected to each other. The valve seat has a first opening, and along the direction from the valve seat to the valve sleeve, the valve sleeve has a second opening and a third opening sequentially, with the inner diameter of the valve sleeve gradually increasing from the first inner diameter to the second inner diameter. The second opening can communicate with the first opening and the third opening. The valve core assembly passes through the valve body assembly, and the outer diameter of the valve core assembly located within the valve sleeve is the same as the second inner diameter. The valve core assembly located within the valve seat can form a line seal with the valve sleeve. The valve core assembly has a leak detection state; when the valve core assembly is in a leak detection state... In the leak test state, the valve core assembly and the valve sleeve form a line seal, the third opening is closed, and along the direction from the valve seat to the valve sleeve, the inner walls of the valve core assembly and the valve sleeve form a first annular cavity and a second annular cavity that are connected. The second opening is connected to the second annular cavity and hydraulic oil is introduced into the second opening. When the hydraulic oil fills the first annular cavity and the second annular cavity, the valve core assembly is subjected to a force from the valve seat to the valve sleeve to ensure that the valve core assembly and the valve sleeve maintain a line seal and to prevent the second opening from communicating with the first opening. The spring is set in the valve seat, with one end abutting against the valve seat and the other end abutting against the valve core assembly. When the valve core assembly is in the leak test state, the spring exerts a force on the valve core assembly from the valve seat to the valve sleeve.

[0029] When performing a leakage test on a hydraulic directional valve, the valve core assembly and valve sleeve are fitted together to form a line seal. The valve core assembly and valve sleeve are separated into a first annular cavity and a second annular cavity. Hydraulic oil is introduced through a second opening, while the third opening remains closed. The hydraulic oil fills the second annular cavity and then further fills the first annular cavity. When the hydraulic oil fills both the first and second annular cavities, it generates an axial force on the valve core assembly from the valve seat to the valve sleeve. This force, combined with the axial force exerted by the spring on the valve core assembly, ensures the line seal between the valve core assembly and the valve sleeve, reducing the amount of hydraulic oil leakage between the valve core assembly and the valve sleeve, and helping to improve the reliability of the hydraulic directional valve.

[0030] The present invention also provides a hydraulic power unit that, by applying the above-mentioned cone valve type zero-leakage hydraulic directional valve, can ensure the consistency of the oil circuit connection sequence of the hydraulic power unit, while ensuring the stability of the hydraulic power unit. Attached Figure Description

[0031] Figure 1 This is an exploded view of the cone valve type zero-leakage hydraulic directional valve described in the embodiment of the present invention;

[0032] Figure 2 This is a cross-sectional view of the cone valve type zero-leakage hydraulic directional valve described in an embodiment of the present invention;

[0033] Figure 3 This is an isometric view of the valve core assembly described in an embodiment of the present invention;

[0034] Figure 4 This is a cross-sectional view of the valve core assembly described in an embodiment of the present invention;

[0035] Figure 5 This is an isometric view of the slide valve described in an embodiment of the present invention;

[0036] Figure 6 yes Figure 5 A magnified view of a portion of point A in the middle.

[0037] In the picture:

[0038] 1. Valve body assembly; 11. Valve seat; 111. First opening; 12. Valve sleeve; 121. Second opening; 122. Third opening; 13. First surrounding cavity; 14. Second surrounding cavity;

[0039] 2. Valve core assembly; 21. Spool valve; 211. First valve section; 212. Second valve section; 2121. Buffer groove; 2122. Pilot groove; 213. Third valve section; 214. Fourth valve section; 215. Fifth valve section; 2151. Snap-fit ​​groove; 22. Cone valve; 221. Cone sealing part; 2211. Sealing groove; 222. Abutment part;

[0040] 3. Spring;

[0041] 4. Snap ring;

[0042] 5. Sealing ring. Detailed Implementation

[0043] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0044] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0047] This embodiment provides a cone valve type zero-leakage hydraulic directional valve, such as... Figure 1 and Figure 2 As shown, the valve body assembly 1, valve core assembly 2, and spring 3 are included. The valve body assembly 1 includes a valve seat 11 and a valve sleeve 12 connected to each other. The valve seat 11 has a first opening 111. Along the direction from the valve seat 11 to the valve sleeve 12, the valve sleeve 12 has a second opening 121 and a third opening 122 in sequence, and the inner diameter of the valve sleeve 12 gradually increases from the first inner diameter to the second inner diameter. The second opening 121 can communicate with the first opening 111 and the third opening 122. The valve core assembly 2 passes through the valve body assembly 1. The outer diameter of the valve core assembly 2 located in the valve sleeve 12 is the same as the second inner diameter, and the valve core assembly 2 located in the valve seat 11 can form a line seal with the valve sleeve 12. The valve core assembly 2 has a leak detection state. When the valve core assembly 2 is in the leak detection state, the valve core assembly 2 and the valve sleeve 12 are sealed together. A line seal is formed, the third opening 122 is closed, and along the direction from valve seat 11 to valve sleeve 12, the inner walls of valve core assembly 2 and valve sleeve 12 form a first surrounding cavity 13 and a second surrounding cavity 14 that are connected. The second opening 121 is connected to the second surrounding cavity 14 and hydraulic oil is introduced into the second opening 121. When the hydraulic oil fills the first surrounding cavity 13 and the second surrounding cavity 14, the valve core assembly 2 is subjected to a force from valve seat 11 to valve sleeve 12 to ensure that the valve core assembly 2 and valve sleeve 12 maintain a line seal, so as to avoid the second opening 121 from communicating with the first opening 111. The spring 3 is disposed in the valve seat 11, one end of which abuts against the valve seat 11 and the other end abuts against the valve core assembly 2. When the valve core assembly 2 is in the leak detection state, the spring 3 applies a force to the valve core assembly 2 from valve seat 11 to valve sleeve 12.

[0048] When performing a leakage test on the hydraulic directional valve, the valve core assembly 2 and the valve sleeve 12 are fitted together to form a line seal. The valve core assembly 2 and the valve sleeve 12 are separated to form a first annular cavity 13 and a second annular cavity 14. Hydraulic oil is introduced through the second opening 121, and the third opening 122 remains closed. The hydraulic oil fills the second annular cavity 14 and then further fills the first annular cavity 13. When the hydraulic oil fills the first annular cavity 13 and the second annular cavity 14, the hydraulic oil generates an axial force on the valve core assembly 2 from the valve seat 11 to the valve sleeve 12. At the same time, combined with the same-direction force applied to the valve core assembly 2 by the spring 3, the dual pressure ensures the line seal between the valve core assembly 2 and the valve sleeve 12, reduces the leakage of hydraulic oil between the valve core assembly 2 and the valve sleeve 12, and helps to improve the reliability of the hydraulic directional valve.

[0049] Specifically, in this embodiment, the cone valve type zero-leakage hydraulic directional valve is a pilot-operated two-position three-way directional valve. In other embodiments, the cone valve type zero-leakage hydraulic directional valve is a pilot-operated two-position four-way directional valve, etc. No limitation is made here.

[0050] Optionally, such as Figures 2-4 As shown, the valve core assembly 2 includes a slide valve 21 and a cone valve 22. The slide valve 21 is disposed inside the valve sleeve 12, and its outer diameter is the same as the second inner diameter. Along the direction from the valve seat 11 to the valve sleeve 12, the slide valve 21 sequentially includes a first valve section 211, a second valve section 212, a third valve section 213, and a fourth valve section 214. The outer diameters of the second valve section 212 and the fourth valve section 214 are both the same as the second inner diameter. When the valve core assembly 2 is in a leak detection state, the outer walls of the second valve section 212, the third valve section 213, and the fourth valve section 214, along with the inner wall of the valve sleeve 12, form a second surrounding cavity 14. Along the direction from the valve seat 11 to the valve sleeve 12, the cross-sectional areas at both ends of the second surrounding cavity 14 are the same. 2 is connected to the first valve section 211. Part of the cone valve 22 is disposed in the valve seat 11, and along the direction from the valve seat 11 to the valve sleeve 12, the cone surface of the cone valve 22 faces the valve sleeve 12. When the valve core assembly 2 is in the leak detection state, the cone valve 22 and the valve sleeve 12 form a line seal. The cone surface of the cone valve 22, the outer wall of the first valve section 211, the outer wall of the second valve section 212 and the inner wall of the valve sleeve 12 surround to form a first surrounding cavity 13. Along the direction from the valve seat 11 to the valve sleeve 12, the difference in cross-sectional area between the two ends of the first surrounding cavity 13 is equal to the difference in area between the second inner diameter and the first inner diameter. When the hydraulic oil fills the first surrounding cavity 13 and the second surrounding cavity 14, the force direction of the slide valve 21 is the direction from the valve seat 11 to the valve sleeve 12.

[0051] In leak detection mode, the cone valve 22 and valve sleeve 12 form a line seal, and the second outlet and third outlet are connected. Since the third outlet is closed, hydraulic oil enters the second annular cavity 14 through the second opening 121 until it is full. Because the cross-sectional areas at both ends of the second annular cavity 14 are the same along the direction from valve seat 11 to valve sleeve 12, the axial forces of the hydraulic oil in the second annular cavity 14 on the slide valve 12 cancel each other out. Afterwards, the hydraulic oil seeps out from the gap between the second valve section 212 and valve sleeve 12 into the first annular cavity 13. Along the direction from valve seat 11 to valve sleeve 12, there is a difference in the cross-sectional area between the two ends of the first surrounding cavity 13. This difference is the area difference between the second inner diameter and the first inner diameter. When the hydraulic oil fills the first surrounding cavity 13, the direction of the force exerted by the hydraulic oil on the valve core 21 is from valve seat 11 to valve sleeve 12, ensuring a line seal between the cone valve 22 and the valve sleeve 12. This means the valve core 21 tends to move from valve seat 11 to valve sleeve 12, always tending to disconnect the connection between the first opening 111 and the second opening 121. Through this configuration, the hydraulic oil forms a fixed-direction driving force based on the cross-sectional difference of the first surrounding cavity 13, continuously pushing the valve core 21 towards the valve sleeve 12, maintaining the line seal between the cone valve 22 and the valve sleeve 12, and further ensuring the sealing reliability of the cone valve 22 and the valve sleeve 12 on the first inner diameter side. This makes the sealing state more stable and prevents oil leakage between the first opening 111 and the second opening 121.

[0052] Specifically, in this embodiment, the cone valve 22 is snap-fitted to the slide valve 21. In other embodiments, the cone valve 22 is threaded to the slide valve 21, etc. No limitation is made here, as long as a stable and fixed connection between the cone valve 22 and the slide valve 21 is maintained.

[0053] Optionally, such as Figure 3 and Figure 4 As shown, along the direction from valve sleeve 12 to valve seat 11, spool valve 21 also includes a fifth valve section 215 connected to the first valve section 211. Cone valve 22 is sleeved on the fifth valve section 215 and abuts against the end face of the first valve section 211. The outer wall of the fifth valve section 215 is recessed with a snap-fit ​​groove 2151. The cone valve type zero-leakage hydraulic directional valve also includes a snap ring 4, which snaps into the snap-fit ​​groove 2151 and abuts against the end face of cone valve 22 opposite to the first valve section 211. Through the abutment of the end face of the first valve section 211 against the cone valve 22, combined with the abutment of the snap ring 4 against the cone valve 22, both ends of cone valve 22 along the axial direction of spool valve 21 are snapped onto spool valve 21 by snap ring 4. This ensures the assembly stability of cone valve 22 on the fifth valve section 215, prevents relative displacement between cone valve 22 and spool valve 21 during leak testing, and ensures a zero-leakage sealing effect.

[0054] Specifically, in this embodiment, the retaining ring 4 is an E-type retaining ring. In other embodiments, the retaining ring 4 can also be a shaft retaining ring or a K-type retaining ring, etc. No limitation is made here.

[0055] Specifically, such as Figure 4 As shown, the cone valve type zero-leakage hydraulic directional valve also includes a sealing ring 5. A sealing groove 2211 is recessed on the inner wall of the cone valve 22 or on the outer wall of the fifth valve section 215, and the sealing ring 5 is housed within the sealing groove 2211. By providing the sealing ring 5 between the fifth valve section 215 and the cone valve 22, hydraulic oil is prevented from leaking from the contact surface between the cone valve 22 and the first valve section 211 into the valve seat 11. Furthermore, the sealing ring 5 further increases the friction between the fifth valve section 215 and the cone valve 22, improving the positional stability of the cone valve 22 on the fifth valve section 215.

[0056] More specifically, in this embodiment, the inner wall of the cone valve 22 is recessed with a sealing groove 2211. In other embodiments, the outer wall of the fifth valve section 215 is recessed with a sealing groove 2211. No limitations are imposed here.

[0057] It is worth noting that in this embodiment, only one sealing groove 2211 is provided. In other embodiments, two or three sealing grooves 2211 are provided, and they are arranged at intervals along the axial direction of the slide valve 21, etc. No limitation is made here.

[0058] More specifically, in this embodiment, the sealing ring 5 is an O-ring. In other embodiments, the sealing ring 5 is a Y-ring or a U-ring, etc. No limitation is made here.

[0059] Optionally, such as Figure 2 and Figure 4 As shown, the cone valve 22 includes a cone sealing portion 221 and an abutment portion 222. The cone sealing portion 221 is provided with a cone surface. The abutment portion 222 is integrally formed and connected to the cone sealing portion 221, and extends along the direction from the valve sleeve 12 to the valve seat 11. The spring 3 is sleeved on the abutment portion 222 and abuts against the cone sealing portion 221. When the spring 3 is compressed or returns to its normal state, it will move along the axial direction of the slide valve 21. Sleeving the spring 3 on the abutment portion 222 can provide a stable mounting carrier for the spring 3, avoid axial displacement of the spring 3 during operation, ensure the reliability of the spring 3, and further ensure the stability of the force exerted by the spring 3 on the cone valve 22.

[0060] Optionally, such as Figure 5As shown, a buffer groove 2121 is recessed on the outer wall of the second valve section 212, and the buffer groove 2121 extends along the axial direction of the slide valve 21. When hydraulic oil enters the second surrounding cavity 14 from the second opening 121, it gradually fills the buffer groove 2121. By slowly storing the hydraulic oil, the instantaneous pressure is dissipated, and the hydraulic oil is prevented from suddenly impacting the end face of the second valve section 212.

[0061] Specifically, such as Figure 5 As shown, multiple buffer grooves 2121 are provided, and the multiple buffer grooves 2121 are arranged at intervals along the circumferential direction of the slide valve 21. The multiple buffer grooves 2121 can further buffer the impact of hydraulic oil on the end face of the second valve section 212.

[0062] More specifically, in this embodiment, five buffer slots 2121 are provided. In other embodiments, two, three, four, or six buffer slots 2121 are provided, etc. No limitation is made here.

[0063] Optionally, such as Figure 6 As shown, the outer wall of the second valve section 212 is also recessed with a pilot groove 2122, which communicates with the buffer groove 2121, and the recessed depth of the pilot groove 2122 is less than the depth of the buffer groove 2121. When the second annular cavity 14 is filled with hydraulic oil, the hydraulic oil will enter the first annular cavity 13 through the pilot groove 2122, which can guide the flow of hydraulic oil in advance and avoid turbulence or impact when the hydraulic oil directly rushes into the first annular cavity 13. At the same time, the pilot groove 2122 is shallower, which prevents a large amount of hydraulic oil from entering the first annular cavity 13 at the same time, and improves the overall smoothness of conduction through the pilot groove 2122.

[0064] Specifically, such as Figure 6 As shown, in this embodiment, the pilot channel 2122 is a V-shaped channel with the sharp corner facing the first valve section 211. The V-shaped channel is used as a throttling or unloading structure, and the hydraulic oil gradually enters the first surrounding cavity 13 from the sharp corner, avoiding pressure pulsation caused by sudden changes in hydraulic oil flow and reducing the vibration and noise of the hydraulic directional valve.

[0065] During assembly, the zero-leakage conical valve hydraulic directional valve is assembled by moving the spool valve 21 from the opening of the second inner diameter of the valve sleeve 12 to the opening of the first inner diameter of the valve sleeve 12. Then, the conical valve 22 and the O-ring are assembled onto the fifth valve section 215 of the spool valve 21. Finally, an E-type snap ring is used to secure it to the snap-fit ​​groove 2151, thus confining the conical valve 22 between the first valve section 211 and the fifth valve section 215 of the spool valve 21. This allows the entire valve core assembly 2 to perform normal reciprocating axial movement within the valve sleeve 12 and the valve seat 11. Simultaneously, due to the pressure difference between the valve seat 11 and the valve sleeve 12, the machining tolerance requirements at the first inner diameter of the valve sleeve 3 are relatively relaxed.

[0066] This embodiment also provides a hydraulic power unit, characterized in that the hydraulic power unit includes an integrated block and a cone-type zero-leakage hydraulic directional valve, the cone-type zero-leakage hydraulic directional valve being disposed on the integrated block. By setting the cone-type zero-leakage hydraulic directional valve on the integrated block, the leakage of hydraulic oil between the valve core assembly 2 and the valve sleeve 12 is reduced, which helps to improve the reliability of the hydraulic directional valve, ensures the consistency of the oil circuit connection sequence of the hydraulic power unit, and at the same time ensures the stability of the hydraulic power unit.

[0067] Optionally, the integrated block has a hydraulic oil port. The cone valve type zero-leakage hydraulic directional valve includes a valve seat 11 and a valve sleeve 12. The valve sleeve 12 is located inside the hydraulic oil port, and the valve seat 11 is threadedly connected to the hydraulic oil port, and the valve seat 11 abuts against the valve sleeve 12. The setting of the valve seat 11 ensures the stability of the valve sleeve 12 within the hydraulic oil port.

[0068] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A zero-leakage hydraulic directional control valve of the poppet valve type, characterized in that, include: The valve body assembly (1) includes a valve seat (11) and a valve sleeve (12) connected to each other. The valve seat (11) has a first opening (111). Along the direction from the valve seat (11) to the valve sleeve (12), the valve sleeve (12) has a second opening (121) and a third opening (122) in sequence. The inner diameter of the valve sleeve (12) gradually increases from the first inner diameter to the second inner diameter. The second opening (121) can communicate with the first opening (111) and the second opening (121) can communicate with the third opening (122). A valve core assembly (2) is inserted into the valve body assembly (1). The outer diameter of the valve core assembly (2) located inside the valve sleeve (12) is the same as the second inner diameter, and the valve core assembly (2) located inside the valve seat (11) can form a line seal with the valve sleeve (12). The valve core assembly (2) has a leak detection state. When the valve core assembly (2) is in the leak detection state, the valve core assembly (2) forms a line seal with the valve sleeve (12), the third opening (122) is closed, and along the direction from the valve seat (11) to the valve sleeve (12), the valve core assembly (2) and the valve sleeve (12) form a line seal. The inner wall of 12) forms a first surrounding cavity (13) and a second surrounding cavity (14) that are connected. The second opening (121) is connected to the second surrounding cavity (14). Hydraulic oil is introduced into the second opening (121). When the hydraulic oil fills the first surrounding cavity (13) and the second surrounding cavity (14), the valve core assembly (2) is subjected to a force from the valve seat (11) to the valve sleeve (12) to ensure that the valve core assembly (2) and the valve sleeve (12) maintain a line seal to avoid the second opening (121) from communicating with the first opening (111). A spring (3) is disposed inside the valve seat (11), with one end abutting against the valve seat (11) and the other end abutting against the valve core assembly (2). When the valve core assembly (2) is in the leak detection state, the spring (3) exerts a force on the valve core assembly (2) from the valve seat (11) to the valve sleeve (12).

2. The zero-leakage poppet hydraulic directional valve according to claim 1, characterized in that, The valve core assembly (2) includes: A slide valve (21) is disposed inside the valve sleeve (12). The outer diameter of the slide valve (21) is the same as the second inner diameter. Along the direction from the valve seat (11) to the valve sleeve (12), the slide valve (21) sequentially includes a first valve section (211), a second valve section (212), a third valve section (213), and a fourth valve section (214). The outer diameters of the second valve section (212) and the fourth valve section (214) are the same as the second inner diameter. When the valve core assembly (2) is in a leak detection state, the outer wall of the second valve section (212), the outer wall of the third valve section (213), the outer wall of the fourth valve section (214), and the inner wall of the valve sleeve (12) surround to form a second surrounding cavity (14). Along the direction from the valve seat (11) to the valve sleeve (12), the cross-sectional areas at both ends of the second surrounding cavity (14) are the same. A cone valve (22) is connected to the first valve section (211). Part of the cone valve (22) is disposed inside the valve seat (11) and along the direction from the valve seat (11) to the valve sleeve (12), the cone surface of the cone valve (22) faces the valve sleeve (12). When the valve core assembly (2) is in a leak detection state, the cone valve (22) and the valve sleeve (12) form a line seal. The cone surface of the cone valve (22), the outer wall of the first valve section (211), and the second valve section (211) form a line seal. The outer wall of 212) and the inner wall of the valve sleeve (12) form the first surrounding cavity (13). Along the direction from the valve seat (11) to the valve sleeve (12), the difference in cross-sectional area between the two ends of the first surrounding cavity (13) is equal to the difference in area between the second inner diameter and the first inner diameter. When the hydraulic oil fills the first surrounding cavity (13) and the second surrounding cavity (14), the direction of force on the slide valve (21) is from the valve seat (11) to the valve sleeve (12).

3. The zero-leakage poppet hydraulic directional control valve according to claim 2, characterized in that Along the direction from the valve sleeve (12) to the valve seat (11), the slide valve (21) further includes a fifth valve section (215) connected to the first valve section (211), the cone valve (22) is sleeved on the fifth valve section (215) and abuts against the end face of the first valve section (211), the outer wall of the fifth valve section (215) is recessed with a snap-fit ​​groove (2151), and the cone valve type zero-leakage hydraulic directional valve further includes: A retaining ring (4) is engaged in the retaining groove (2151) and abuts against the end face of the cone valve (22) away from the first valve section (211).

4. The zero leakage poppet hydraulic directional control valve according to claim 3, wherein, The cone valve type zero-leakage hydraulic directional valve also includes: The sealing ring (5) is provided with a sealing groove (2211) on the inner wall of the cone valve (22) or the sealing groove (2211) is provided on the outer wall of the fifth valve section (215), and the sealing ring (5) is housed in the sealing groove (2211).

5. The zero leakage poppet hydraulic directional control valve of claim 2 wherein, The cone valve (22) includes: A conical sealing portion (221) is provided with the conical surface; The abutting part (222) is integrally formed and connected with the cone sealing part (221), and the abutting part (222) extends along the direction from the valve sleeve (12) to the valve seat (11). The spring (3) is sleeved on the abutting part (222) and abuts against the cone sealing part (221).

6. The cone valve type zero-leakage hydraulic directional valve according to any one of claims 2-5, characterized in that, The outer wall of the second valve section (212) is recessed with a buffer groove (2121), and the buffer groove (2121) extends along the axial direction of the slide valve (21).

7. The cone valve type zero-leakage hydraulic directional valve according to claim 6, characterized in that, Multiple buffer grooves (2121) are provided, and the multiple buffer grooves (2121) are arranged at intervals along the circumferential direction of the slide valve (21).

8. The cone valve type zero-leakage hydraulic directional valve according to claim 6, characterized in that, The outer wall of the second valve section (212) is also recessed with a pilot groove (2122), which is connected to the buffer groove (2121), and the recessed depth of the pilot groove (2122) is less than the depth of the buffer groove (2121).

9. A hydraulic station, characterized in that, The hydraulic station includes an integrated block and a cone valve type zero-leakage hydraulic directional valve as described in any one of claims 1-8, wherein the cone valve type zero-leakage hydraulic directional valve is disposed on the integrated block.

10. The hydraulic station according to claim 9, characterized in that, The integrated block has a hydraulic oil hole. The cone valve type zero-leakage hydraulic directional valve includes the valve seat (11) and the valve sleeve (12). The valve sleeve (12) is located in the hydraulic oil hole. The valve seat (11) is threadedly connected to the hydraulic oil hole, and the valve seat (11) abuts against the valve sleeve (12).

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