programmed valve

Abstract

This invention discloses a programmable valve, comprising a valve body, a valve cover, a valve stem, and an actuator. The valve body has a first channel, a second channel, a valve seat, and a connecting channel. A mating hole is provided on the second channel. The valve cover is located opposite the opening of the second channel. The valve stem passes through the valve cover. One end of the valve stem protruding from the valve body is linked with the actuator, and the other end is fixed with a small valve core. The small valve core has a balancing channel. A flexible sealing assembly is provided at the end of the small valve core away from the valve stem. The flexible sealing assembly includes a valve disc with a balancing hole. A piston is sleeved and fixed on the small valve core. A sleeve is sleeved around the piston. The end of the sleeve away from the valve cover has a retaining bottom. The inside of the sleeve is divided by the piston to form an upper balancing chamber and a lower balancing chamber. An extension channel is provided on the balancing channel. An upper pressure-inlet hole is provided on the piston, and a lower pressure-inlet hole is provided on the retaining bottom. The pressure-balanced valve internal structure formed by the upper and lower balancing chambers and the piston can meet the requirement of opening and closing time ≤2s.

Description

Technical Field

[0001] This invention belongs to the field of valve technology, and specifically relates to a programmable valve. Background Technology

[0002] A programmable valve (CVP) is a pneumatically or hydraulically driven shut-off valve that connects to a DCS or PLC system for remote program control. It is primarily used in pressure swing adsorption (PSA) gas separation. Unlike ordinary valves, it integrates program control, power drive, and status feedback, eliminating the need for manual on-site operation. It boasts advantages such as fast response, high control accuracy, and adaptability to high-frequency sequential operating conditions. A CVP consists of components including a valve body, valve seat, valve disc, valve stem, valve cover, sealing components, and actuator. These components work together to complete preset actions, ensuring operational stability and control accuracy.

[0003] In core high-frequency operating conditions such as pressure swing adsorption (PSA) gas separation, the programmable valve (CVT) is a core actuator of the process system. It must simultaneously meet the composite requirements of Class VI zero-leakage sealing, a full-stroke opening / closing time ≤2s, and ≥200,000 cycles per year. This places high demands on the valve's structural design, mechanical performance, sealing reliability, and fatigue life of moving parts. Specifically: It must ensure rapid opening and closing while suppressing rigid impacts from high-frequency movements, preventing valve disc and seat from impacting, deforming, or cracking, and ensuring smooth and controllable operation throughout the entire stroke; it must maintain Class VI zero-leakage sealing performance over the long term, eliminating the negative impact of internal media leakage on product purity and separation efficiency, and ensuring long-term stable operation of the unit; it must address the issues of uneven loading and poor contact between the valve disc and seat sealing surfaces under high-speed closing conditions, ensuring uniform contact across the entire circumference even under high-speed impact, balancing rapid action and sealing effectiveness; and it must ensure that moving parts and seals possess superior wear and fatigue resistance, adapting to over 200,000 high-frequency reciprocating movements per year, meeting the requirements for long-term continuous operation of the unit.

[0004] For programmable valves with large nominal diameters, especially DN≥250, existing conventional structures are unable to meet the above design requirements, and the following technical bottlenecks exist: First, the pressure-bearing area of ​​the valve core increases quadratically with the increase of the valve diameter. Under the pressure difference of the working condition, the huge unbalanced force of the medium will be generated. Conventional unbalanced single-seat structures will generate huge axial unbalanced forces of the medium under the pressure difference of the working condition. A large-diameter pneumatic actuator must be matched to provide sufficient opening and closing driving force. In addition, the long stroke of the large-diameter valve further leads to a large actuator chamber volume, slow air source pressure rise, and long air charging response time. Ultimately, it is difficult for the opening and closing speed of the large-diameter actuator to meet the design requirement of ≤2s. The driving force output and rapid opening and closing performance cannot be balanced.

[0005] Secondly, due to the influence of the manufacturing precision of parts (coaxiality, flatness, etc.) and the cumulative assembly error, the conventional rigid connection valve disc structure is prone to sealing surface position deviation and angular off-center load when closing at high speed, which makes it impossible for the sealing surface to fit evenly around the whole circumference, resulting in continuous internal leakage. Especially under high-frequency impact conditions, off-center loading will also cause local stress concentration and aggravated erosion and wear on the sealing surface, further accelerating the seal failure and failing to meet the long-term stable requirements of zero leakage seal.

[0006] Third, the stem diameter and reciprocating stroke of large-diameter process control valves increase synchronously with the increase of the diameter. Under high-frequency reciprocating motion conditions of more than 200,000 times per year, the cumulative friction stroke and cyclic wear frequency of the valve stem and sealing packing increase exponentially. Conventional fixed packing seal structures cannot dynamically compensate for wear, which easily leads to rapid wear of the packing and leakage of the medium. This not only fails to meet the sealing and safety requirements of long-term operation of the valve, but also significantly increases the maintenance frequency and downtime risk of the device. Summary of the Invention

[0007] In order to overcome the shortcomings of the prior art, the present invention provides a programmable valve that can still meet the requirements of high frequency opening and closing, fast response and high sealing level when the nominal diameter is large.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a programmable valve, comprising a valve body, a valve cover, a valve stem, and an actuator. The valve body has a first channel, a second channel, a valve seat, and a connecting channel. The connecting channel connects the first channel and the second channel. The second channel has a mating hole opposite to the connecting channel. The valve cover is placed over the opening of the mating hole opposite to the opening of the second channel, and the valve cover is fixedly connected to the valve body by fixing bolts. The valve stem passes through the valve cover. The actuator is drivenly connected to one end of the valve stem protruding from the valve body. A small valve core is coaxially fixed to the end of the valve stem away from the actuator. A balance channel is coaxially provided on the small valve core, with both ends connected. A flexible sealing assembly is provided on the end of the small valve core away from the valve stem, which can form a seal with the valve seat. The flexible sealing assembly includes a valve disc flexibly connected to the small valve core. The valve disc has a balance hole coaxially corresponding to the balance channel. A piston is fitted and fixed on the small valve core. A sleeve is fitted over the piston. The outer peripheral wall of the piston and the inner wall of the sleeve are dynamically sealed together. The end of the sleeve away from the valve cover is provided with a bottom enclosure surrounding the small valve core. The end face of the valve cover facing the piston, the end face of the piston facing the valve cover, and the inner wall of the sleeve enclose and form an upper balance cavity. The end face of the bottom enclosure facing the piston, the end face of the piston facing the bottom enclosure, and the inner wall of the sleeve enclose and form a lower balance cavity. The inner wall of the balance channel is provided with at least two extension channels extending radially along the balance channel. The piston is provided with at least two upper pressure holes connecting the upper balance cavity and the extension channels. The enclosing bottom is provided with at least two lower pressure holes connecting the inside and outside of the lower balance cavity. The extension channels, upper pressure holes and lower pressure holes are all uniformly arranged circumferentially around the axis of the balance channel.

[0009] In the above-described scheme, the flexible connection refers to the valve disc being firmly connected to the small valve core while also allowing for controlled, small-amplitude free oscillation relative to the small valve core. Compared to existing unbalanced single-seat sealing structures, this invention, through its pressure-balanced internal valve structure consisting of an upper and lower balance chamber and a piston, can significantly offset the unbalanced force exerted by the medium in the opening and closing direction, significantly reducing the required output thrust of the actuator. This, in turn, reduces the cylinder diameter of the actuator, shortens the gas charging response time, and ensures rapid valve opening and closing. Combined with the flexible sealing component, while meeting the design requirement of an opening and closing time ≤2s, it also ensures the sealing performance of this invention under high-speed opening and closing. Simultaneously, the circumferentially evenly distributed extension channels, upper pressure holes, and lower pressure holes ensure that the medium enters the upper and lower balance chambers uniformly, preventing the piston from being jammed due to uneven load and improving the stability of valve operation.

[0010] The pressure-balanced valve internal structure and the flexible sealing assembly work synergistically and complement each other. The pressure balancing mechanism is a prerequisite for the flexible sealing assembly to function fully. Without a pressure balancing structure, the huge unbalanced force generated by the medium pressure difference may lead to the failure of the flexible connection and uncontrolled valve disc sway. Conversely, the flexible sealing assembly ensures the continuous stability of the pressure balancing effect, preventing problems such as balancing failure caused by internal valve leakage. The two work together to resolve the contradiction between opening and closing speed and sealing reliability under high-speed opening and closing conditions, achieving a comprehensive effect of high-speed valve opening and closing, zero-leakage sealing, and long-term stable operation.

[0011] As a further feature of the present invention, the flexible sealing assembly further includes a limiting sleeve, a limiting sleeve sealing ring, and a small valve core sealing ring. The valve disc is provided with an installation groove for inserting the small valve core, and the balance hole is coaxially formed at the bottom of the installation groove. The limiting sleeve is sleeved on the small valve core and disposed between the small valve core and the installation groove. The outer wall of the limiting sleeve is threadedly engaged with the inner wall of the installation groove. A limiting sleeve pin is inserted into the limiting sleeve and the valve disc to keep the limiting sleeve and the valve disc relatively fixed. The small valve core is provided with an end face that can form a shape with the end face of the limiting sleeve facing away from the sleeve. The limiting sleeve has a lower step surface; the limiting sleeve has an annular limiting sleeve sealing groove on the surface facing the axis of the small valve core, and the limiting sleeve sealing ring is set in the limiting sleeve sealing groove; the small valve core has a small valve core sealing groove surrounding the balance channel on the surface facing the bottom of the mounting groove, and the small valve core sealing ring is set in the small valve core sealing groove; floating gaps are reserved between the outer wall of the small valve core facing the limiting sleeve and the inner wall of the limiting sleeve, between the surface of the limiting sleeve facing the lower step surface and the lower step surface, and between the outer wall of the small valve core facing the mounting groove and the inner wall of the mounting groove.

[0012] Using the above scheme, the thrust of the actuator is transmitted to the valve disc through the valve stem and small valve core to achieve valve closure. This invention connects the valve stem and valve disc with an independently set small valve core, and uses a limiting sleeve to axially limit the valve disc and small valve core. Simultaneously, the reserved floating gap, combined with the sealing rings of the limiting sleeve and small valve core, achieves sealing of the floating gap, giving the valve disc a flexible adaptive capability in both radial and angular directions. This eliminates positional errors caused by manufacturing precision and assembly issues during closure, ensuring uniform contact between the valve disc and valve seat throughout the circumference, significantly improving sealing reliability.

[0013] As a further feature of the present invention, a contact surface is provided at the orifice of the balance hole facing the small valve core. The contact surface is a frustum-shaped conical surface. An abutment surface is provided on the surface of the small valve core facing the balance hole, which abuts against the contact surface. The abutment surface is an arc-shaped spherical surface. The openings of the small valve core sealing groove and the balance channel facing the balance hole are both provided on the abutment surface.

[0014] By adopting the above scheme, the matching structure of the contact surface and the abutment surface can achieve automatic centering of the valve disc and the small valve core while ensuring the smooth self-adaptive effect of the valve disc. It can also ensure the coaxiality of the balance channel and the balance hole, avoid abnormal medium flow resistance caused by eccentricity, and at the same time, the line contact matching of the spherical surface and the conical surface can ensure uniform stress and improve the structural strength and erosion resistance.

[0015] As a further feature of the present invention, the flexible sealing assembly further includes a pressure ring and a valve disc sealing ring. The valve disc has a valve disc limiting groove on its surface facing the valve seat. Both the pressure ring and the valve disc sealing ring are disposed within the valve disc limiting groove. The pressure ring and the valve disc are fixed together by fastening screws. The valve disc sealing ring is located on the side of the pressure ring away from the balance hole. The surfaces of the pressure ring and the valve disc sealing ring that are in contact with each other are inclined surfaces that are away from the bottom of the valve disc limiting groove and tilt away from the balance hole. The surfaces of the valve disc and the valve seat that are opposite each other are mirror surfaces. The pressure ring and fastening screw are arranged opposite to the connecting channel, and the valve disc sealing ring is arranged opposite to the valve seat.

[0016] Using the above scheme, the valve disc sealing ring is made of PTFE and is pressed into the valve disc limiting groove by a pressure ring. When the valve is open, the valve disc sealing ring protrudes from the valve disc limiting groove; when the valve is closed, the valve disc sealing ring fits tightly against the valve seat to form a soft seal, and the surface of the valve disc facing the valve seat fits tightly against the valve seat to form a hard seal. Both the opposing surfaces of the valve disc and the valve seat are mirror-like, ensuring the sealing effect of the hard seal. With the valve disc possessing a flexible self-adaptive effect, the composite seal of soft and hard seals achieves a Class VI zero-leakage sealing effect, effectively preventing media leakage.

[0017] As a further feature of the present invention, the end face of the small valve core away from the valve disc is provided with a small valve core fixing groove, the small valve core fixing groove is coaxially connected with the balance channel, the end of the valve stem away from the actuator is inserted into the small valve core fixing groove and threadedly engaged with the small valve core fixing groove, and a valve stem pin for inserting the valve stem is provided on the outer wall of the small valve core corresponding to the small valve core fixing groove; the outer wall of the small valve core located inside the sleeve is provided with an upper stepped surface, and a fixing nut is threadedly fitted onto the small valve core; the two opposite ends of the piston form a limiting fit with the upper stepped surface and the fixing nut respectively, and an inner piston sealing ring is provided between the piston and the upper stepped surface.

[0018] By adopting the above solution, a double fixing structure of threaded fit and valve stem pin is used to achieve a coaxial rigid connection between the valve stem and the small valve core, avoiding loosening under long-term high-frequency operation; at the same time, the piston is axially fixed on the small valve core by the bidirectional clamping of the upper stepped surface and the fixing nut, and the piston inner sealing ring is used to achieve static sealing between the piston and the small valve core, preventing cross-flow between the upper and lower balance chambers and ensuring stable pressure balance.

[0019] As a further feature of the present invention, the inner wall of the piston is provided with an annular inner groove, the extension channel is disposed opposite to the inner groove, the surface of the piston facing away from the valve disc is provided with an annular upper groove, the outer diameter of the fixing nut is between the outer diameter and the inner diameter of the upper groove, the upper groove is close to the inner sidewall of the small valve core, and its side close to the fixing nut is inclined towards the axis of the small valve core; the two orifices of the upper pressure hole are respectively located at the bottom of the inner groove and on the inner sidewall of the upper groove close to the small valve core; the outer peripheral wall of the piston is provided with an annular piston limiting groove one and an annular piston limiting groove two, the piston limiting groove one is provided with a PTFE ring, and the piston limiting groove two is provided with a piston outer sealing ring.

[0020] By adopting the above scheme, the setting of the inner groove and the upper groove significantly reduces the machining accuracy of the upper pressure hole, ensuring that the upper balance cavity and the extension channel can be fully connected within the assembly error range. It is not necessary to strictly ensure the coaxial alignment of the extension channel and the upper pressure hole, which greatly reduces the assembly difficulty of the piston and the small valve core, and ensures that the medium enters the upper balance cavity stably and uniformly from the balance channel, so that the amount of medium entering the upper balance cavity per unit time meets the design expectation.

[0021] In addition to the piston external sealing ring to achieve dynamic sealing with the sleeve, the piston movement is guided by the addition of a PTFE ring, ensuring no metal contact between the piston and the inner wall of the sleeve. This avoids wear and jamming between the sleeve and piston under long-term high-frequency operation, while reducing motion friction resistance and further improving the smoothness of piston movement and valve opening and closing response speed.

[0022] As a further feature of the present invention, the valve cover is provided with an inlet / outlet groove on the surface facing the sleeve for the fixing nut to move axially with the valve stem. The bottom of the inlet / outlet groove facing the upper balance chamber is provided with an assembly groove. A guide sleeve is assembled in the assembly groove. The guide sleeve and the valve cover are fixed by a guide sleeve pin. The side of the valve stem away from the valve disc passes through the guide sleeve and exits the valve cover from the bottom of the assembly groove. An oilless bearing is assembled between the guide sleeve and the valve stem.

[0023] By adopting the above solution, the guide sleeve and oilless bearing can provide precise radial guidance for the valve stem. Together with the PTFE ring on the piston, they form a dual-guide structure for the valve's moving parts, which greatly improves the centering and stability of the valve stem and piston movement, reduces the wear of the inner wall of the sleeve, the piston and various seals under long-term high-frequency operation, and extends the service life of the entire valve.

[0024] As a further feature of the present invention, the actuator includes a bracket, and the valve cover has a sealing cavity surrounding the valve stem on the surface facing the bracket. The sealing cavity contains a lower gasket, a V-shaped packing, an upper gasket, a packing gland, and a packing pressure plate, which are sequentially fitted onto the valve stem in a direction away from the valve disc. The packing pressure plate, the bracket, and the valve cover are fixed by pressure plate bolts. The outer wall of the packing gland has a gland step surface, and a butterfly spring is fitted on the packing gland. The butterfly spring is located between the gland step surface and the packing pressure plate. Multiple V-shaped packings and butterfly springs are provided. A packing gland sealing ring is provided between the outer wall of the packing gland and the valve cover, and between the inner wall of the packing gland and the valve stem.

[0025] By adopting the above solution, the external sealing effect at the valve stem and valve cover mating point can be guaranteed under long-term, ultra-high frequency operation conditions.

[0026] The V-type packing is made of PTFE and has a low coefficient of friction, which can effectively reduce motion wear. At the same time, the V-shaped structure has strong flexibility and can achieve self-adaptive compensation under pressure. The spring force of the butterfly spring can dynamically compress the V-type packing. Under the dual action of medium pressure and spring force, the V-type packing can compensate for dimensional fluctuations and motion wear caused by temperature changes in real time. Through the live load packing structure of V-type packing + butterfly spring, packing wear is compensated, improving the service life and reliability of dynamic seals.

[0027] As a further feature of the present invention, the outer wall of the limiting sleeve is provided with an annular stroke limiting block, the end face of the stroke limiting block facing away from the valve seat abuts against the end face of the valve disc facing the limiting sleeve, and the surface of the enclosing bottom facing the valve disc is provided with a stroke limiting groove that can form a limiting position with the stroke limiting block, and the small valve core is coaxially inserted through the bottom of the stroke limiting groove.

[0028] By adopting the above solution, the moving parts (valve disc, small valve core, valve stem, piston) of the programmable valve with larger specifications (nominal diameter ≥ DN250) have a large weight. The valve has a large inertia and strong impact force when it is opened and closed quickly. The mechanical hard limit formed by the stroke limit block and the stroke limit groove, combined with the hard seal limit formed by the valve disc facing the valve seat and the valve seat, and the soft seal limit formed by the valve disc sealing ring and the valve seat, can effectively absorb the opening and closing impact, avoid the failure of the single limit structure under high frequency operation, and greatly improve the operation stability and service life of the valve.

[0029] As a further feature of the present invention, annular and coaxially opposite valve body fixing grooves and valve cover fixing grooves are respectively provided on the end faces of the valve body and the valve cover abutting each other. Annular sleeve limiting blocks are provided on the outer wall of the sleeve, which are simultaneously embedded in the valve body fixing groove and the valve cover fixing groove. Annular graphite gaskets are provided between the sleeve limiting block and the bottom of the valve body fixing groove, and between the sleeve limiting block and the bottom of the valve cover fixing groove.

[0030] By adopting the above solution, the sleeve limiting block is clamped by the valve body fixing groove and the valve cover fixing groove to achieve radial and axial positioning of the sleeve. No additional fixing structure is required, which greatly simplifies the assembly process of the sleeve. At the same time, by setting a graphite gasket, static sealing is achieved between the sleeve and the mating surfaces of the valve body and valve cover, preventing media leakage. It can also absorb assembly errors and temperature deformation, thereby improving sealing reliability.

[0031] The present invention will now be further described with reference to the accompanying drawings. Attached Figure Description

[0032] Appendix Figure 1 This is a schematic diagram of an overall embodiment of the present invention; Appendix Figure 2 For the appendix Figure 1 Enlarged view of part A; Appendix Figure 3 For the appendix Figure 2 Enlarged view of section A1; Appendix Figure 4 For the appendix Figure 2 Enlarged view of section A2; Appendix Figure 5 For the appendix Figure 2 Enlarged view of section A3; Appendix Figure 6 For the appendix Figure 1 Enlarged view of part B; Appendix Figure 7 For the appendix Figure 6 Enlarged view of section B1; Appendix Figure 8 For the appendix Figure 1 Enlarged view of part C.

[0033] Valve body 1, Channel 1 11, Channel 2 12, Valve seat 13, Connecting channel 14, Mating hole 15, Valve body fixing groove 16, Valve cover 2, Inlet / outlet groove 21, Assembly groove 22, Guide sleeve 23, Guide sleeve pin 24, Oil-free bearing 25, Valve cover fixing groove 26, Valve stem 3, Valve stem pin 31, Actuator 4, Bracket 41, Small valve core 5, Balance channel 51, Extension channel 511, Lower step surface 52, Small valve core sealing groove 53, Abutment surface 54, Small valve core fixing groove 55, Upper step surface 56, Flexible sealing assembly 6, Valve disc 61, Balance hole 611, Contact surface 6111, Mounting groove 612, Valve disc limiting groove 613, Limiting sleeve 62, Limiting sleeve sealing groove 621, Stroke limiting block 622. Limiting sleeve sealing ring 63, small valve core sealing ring 64, limiting sleeve pin 65, pressure ring 66, valve disc sealing ring 67, piston 7, upper pressure hole 71, piston inner sealing ring 72, inner groove 73, upper groove 74, piston limiting groove one 75, piston limiting groove two 76, PTFE ring 77, piston outer sealing ring 78, sleeve 8, enclosing bottom 81, lower pressure hole 811, upper balance cavity 82, lower balance cavity 83, stroke limiting groove 84, sleeve limiting block 85, fixing nut 9, sealing cavity 10, lower liner 101, V-shaped packing 102, upper liner 103, packing gland 104, gland step surface 1041, packing gland sealing ring 1042, packing pressure plate 105, butterfly spring 106, graphite gasket a. Detailed Implementation

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be noted that, unless otherwise specified, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, to facilitate a clear and intuitive demonstration of the structure of each component of this technical solution and the cooperation relationship between the components, the dimensions of some components have been adaptively adjusted by enlarging or reducing their proportions, and some prior art structures involved in the solution have been simplified; the dimensions and external structures shown in the accompanying drawings should not be directly construed as limitations on the actual size or shape of the product.

[0036] Specific embodiments of the present invention are shown in the accompanying drawings.

[0037] A programmable valve includes a valve body 1, a valve cover 2, a valve stem 3, and an actuator 4. The valve body 1 has a channel 11, a channel 2 12, a valve seat 13, and a connecting channel 14 inside. The connecting channel 14 connects the channel 11 and the channel 2 12. The channel 2 12 has a mating hole 15 opposite to the connecting channel 14. The valve cover 2 is placed on the mating hole 15 away from the opening of the channel 2 12, and the valve cover 2 is fixedly connected to the valve body 1 by fixing bolts. The valve stem 3 passes through the valve cover 2, and the actuator 4 is drivenly connected to the end of the valve stem 3 that protrudes from the valve body 1. A small valve core 5 is coaxially fixed at the end of the valve stem 3 away from the actuator 4. A balance channel 51 with both ends passing through is coaxially provided on the small valve core 5. A flexible sealing assembly 6 that can form a seal with the valve seat 13 is provided at the end of the small valve core 5 away from the valve stem 3. The flexible sealing assembly 6 includes a valve disc 61. A balance hole 611 coaxially corresponding to the balance channel 51 is provided on the valve disc 61. A piston 7 is fitted and fixed on the small valve core 5. A sleeve 8 is fitted on the piston 7. The sleeve 8 is assembled in the mating hole 15. The outer peripheral wall of the piston 7 and the inner wall of the sleeve 8 are dynamically sealed. The end of the sleeve 8 away from the valve cover 2 is provided with a surrounding bottom 81 that surrounds the small valve core 5. The end face of the valve cover 2 facing the piston 7, the end face of the piston 7 facing the valve cover 2, and the inner wall of the sleeve 8 form an upper balance cavity 82. The end face of the surrounding bottom 81 facing the piston 7, the end face of the piston 7 facing the surrounding bottom 81, and the inner wall of the sleeve 8 form a lower balance cavity 83. The inner wall of the balance channel 51 is provided with at least two extension channels 511 extending radially along the balance channel 51. The piston 7 is provided with at least two upper pressure holes 71 connecting the upper balance cavity 82 and the extension channels 511. The enclosing bottom 81 is provided with at least two lower pressure holes 811 connecting the inside and outside of the lower balance cavity 83. The extension channels 511, upper pressure holes 71 and lower pressure holes 811 are all uniformly arranged circumferentially around the axis of the balance channel 51.

[0038] The flexible sealing assembly 6 also includes a limiting sleeve 62, a limiting sleeve sealing ring 63, and a small valve core sealing ring 64. The valve disc 61 is provided with an installation groove 612 for the small valve core 5 to be inserted, and a balance hole 611 is coaxially opened at the bottom of the installation groove 612. The limiting sleeve 62 is sleeved on the small valve core 5 and is located between the small valve core 5 and the installation groove 612. The outer wall of the limiting sleeve 62 is threadedly engaged with the inner wall of the installation groove 612. A limiting sleeve pin 65 is inserted on the limiting sleeve 62 and the valve disc 61 to keep the limiting sleeve 62 and the valve disc 61 relatively fixed. The small valve core 5 is provided with a lower step surface 52 that can form a limiting position with the end face of the limiting sleeve 62 facing away from the sleeve 8.

[0039] The limiting sleeve 62 has an annular limiting sleeve sealing groove 621 on the surface facing the axis of the small valve core 5, and the limiting sleeve sealing ring 63 is disposed in the limiting sleeve sealing groove 621; the small valve core 5 has a small valve core sealing groove 53 surrounding the balance channel 51 on the surface facing the bottom of the mounting groove 612, and the small valve core sealing ring 64 is disposed in the small valve core sealing groove 53; floating gaps H are reserved between the outer wall of the small valve core 5 facing the limiting sleeve 62 and the inner wall of the limiting sleeve 62, between the surface of the limiting sleeve 62 facing the lower step surface 52 and the lower step surface 52, and between the outer wall of the small valve core 5 facing the mounting groove 612 and the inner wall of the mounting groove 612.

[0040] Furthermore, the balance hole 611 is provided with a contact surface 6111 at the opening of the small valve core 5. The contact surface 6111 is a frustum-shaped conical surface. The small valve core 5 is provided with an abutting surface 54 on the surface of the balance hole 611 that abuts against the contact surface 6111. The abutting surface 54 is an arc spherical surface. The openings of the small valve core sealing groove 53 and the balance channel 51 facing the balance hole 611 are both provided on the abutting surface 54.

[0041] The flexible sealing assembly 6 also includes a pressure ring 66 and a valve disc sealing ring 67. A valve disc limiting groove 613 is provided on the surface of the valve disc 61 facing the valve seat 13. Both the pressure ring 66 and the valve disc sealing ring 67 are disposed within the valve disc limiting groove 613. The pressure ring 66 is fixed to the valve disc 61 by fastening screws. The valve disc sealing ring 67 is located on the side of the pressure ring 66 away from the balance hole 611. The surfaces of the pressure ring 66 and the valve disc sealing ring 67 that are in contact are both inclined surfaces on the side away from the bottom of the valve disc limiting groove 613, moving away from the balance hole 611. This inclined surface cooperation achieves stable compression of the valve disc sealing ring 67 by the pressure ring 66. The surfaces of the valve disc 61 and the valve seat 13 facing each other are mirror surfaces. The pressure ring 66 and the fastening screws are positioned opposite to the connecting channel 14, and the valve disc sealing ring 67 is positioned opposite to the valve seat 13.

[0042] The end face of the small valve core 5 away from the valve disc 61 is provided with a small valve core fixing groove 55. The small valve core fixing groove 55 is coaxially connected with the balance channel 51. The end of the valve stem 3 away from the actuator 4 is inserted into the small valve core fixing groove 55 and threadedly engaged with the small valve core fixing groove 55. A valve stem pin 31 for inserting the valve stem 3 is provided on the outer wall of the small valve core 5 corresponding to the small valve core fixing groove 55. The valve stem pin 31 achieves double locking and fixing of the valve stem 3 and the small valve core 5.

[0043] The small valve core 5 has an upper stepped surface 56 on the outer wall inside the sleeve 8. A fixing nut 9 is threaded onto the outer sleeve of the small valve core 5. The two opposite ends of the piston 7 form a limiting fit with the upper stepped surface 56 and the fixing nut 9, respectively. An inner piston sealing ring 72 is provided between the piston 7 and the upper stepped surface 56 to achieve static sealing between the piston 7 and the mating surface of the small valve core 5.

[0044] Furthermore, the inner wall of the piston 7 is provided with an annular inner groove 73, and the extension channel 511 is arranged opposite to the inner groove 73; the surface of the piston 7 facing away from the valve disc 61 is provided with an annular upper groove 74, the outer diameter of the fixing nut 9 is between the outer diameter and the inner diameter of the upper groove 74, the upper groove 74 is close to the inner side wall of the small valve core 5, and its side close to the fixing nut 9 is inclined towards the axis of the small valve core 5. The two openings of the upper pressure hole 71 are respectively located at the bottom of the groove 73 and on the inner side wall of the upper groove 74 near the small valve core 5; the outer peripheral wall of the piston 7 is provided with an annular piston limiting groove one 75 and an annular piston limiting groove two 76, the piston limiting groove one 75 is provided with a PTFE ring 77, and the piston limiting groove two 76 is provided with a piston outer sealing ring 78.

[0045] The valve cover 2 has an inlet / outlet groove 21 on the surface facing the sleeve 8 for fixing the nut 9 to move axially with the valve stem 3. The bottom of the inlet / outlet groove 21 facing the upper balance chamber 82 has an assembly groove 22. A guide sleeve 23 is installed in the assembly groove 22. The guide sleeve 23 is fixed to the valve cover 2 by a guide sleeve pin 24. The side of the valve stem 3 away from the valve disc 61 passes through the guide sleeve 23 and exits the valve cover 2 from the bottom of the assembly groove 22. An oilless bearing 25 is installed between the guide sleeve 23 and the valve stem 3.

[0046] The actuator 4 includes a bracket 41. The valve cover 2 has a sealing cavity 10 surrounding the valve stem 3 on the surface facing the bracket 41. The sealing cavity 10 contains a lower gasket 101, a V-shaped packing 102, an upper gasket 103, a packing gland 104, and a packing pressure plate 105, which are sequentially fitted onto the valve stem 3 in a direction away from the valve disc 61. The packing pressure plate 105, the bracket 41, and the valve cover 2 are fixed by pressure plate bolts. The outer wall of the packing gland 104 has a gland step surface 1041. A butterfly spring 106 is fitted on the packing gland 104. The butterfly spring 106 is located between the gland step surface 1041 and the packing pressure plate 105. Multiple V-shaped packing 102 and butterfly springs 106 are provided. A packing gland sealing ring 1042 is provided between the outer wall of the packing gland 104 and the valve cover 2, and between the inner wall of the packing gland 104 and the valve stem 3.

[0047] The outer wall of the limiting sleeve 62 is provided with an annular stroke limiting block 622. The end face of the stroke limiting block 622 facing away from the valve seat 13 abuts against the end face of the valve disc 61 facing the limiting sleeve 62. The surface of the enclosing bottom 81 facing the valve disc 61 is provided with a stroke limiting groove 84 that can form a limit with the stroke limiting block 622. The small valve core 5 is coaxially inserted through the bottom of the stroke limiting groove 84.

[0048] On the end face where the valve body 1 and the valve cover 2 abut, there are respectively annular and coaxially opposite valve body fixing grooves 16 and valve cover fixing grooves 26. The outer wall of the sleeve 8 is provided with annular sleeve limiting blocks 85 that are simultaneously embedded in the valve body fixing groove 16 and the valve cover fixing groove 26. There are annular graphite gaskets a between the sleeve limiting block 85 and the bottom of the valve body fixing groove 16, and between the sleeve limiting block 85 and the bottom of the valve cover fixing groove 26.

[0049] The working principle of this embodiment is as follows: During operation, the actuator 4 drives the valve stem 3, which in turn drives the small valve core 5, piston 7, and valve disc 61 to reciprocate axially, thereby opening and closing the valve. When the valve is closed, the actuator 4 pushes the valve stem 3 downward. The valve stem 3 drives the small valve core 5, piston 7 and valve disc 61 to move towards the valve seat 13 until the valve disc sealing ring 67 is tightly fitted with the valve seat 13 to form a soft seal. At the same time, the valve disc 61 is tightly fitted with the mirror end face of the valve seat 13 to form a hard seal, thus completing the valve closure and achieving a Class VI zero-leakage sealing effect. In this embodiment, the valve disc sealing ring 67 is made of PTFE material, the valve stem 3 is made of 410 stainless steel with nitriding treatment, and the opposing surfaces of the valve disc 61 and the valve seat 13 are hardened with Stellite alloy.

[0050] When the valve is opened, the actuator 4 drives the valve stem 3 to move upward. The valve stem 3 drives the small valve core 5, piston 7 and valve disc 61 away from the valve seat 13. The medium flows from channel 11 through connecting channel 14 into channel 2 12, thus completing the valve opening.

[0051] During the entire valve opening and closing process, the medium enters the extension channel 511 through the balance hole 611 and balance channel 51, and then enters the upper balance chamber 82 evenly through the upper pressure hole 71; simultaneously, the medium enters the lower balance chamber 83 through the lower pressure hole 811, ensuring that both the upper balance chamber 82 and the lower balance chamber 83 are filled with the same medium pressure as before the valve. The pressure at both ends of the piston 7 cancels each other out, significantly reducing the unbalanced force of the medium acting on the valve opening and closing direction, significantly reducing the output thrust required by the actuator 4, thereby reducing the cylinder diameter of the actuator 4, shortening the charging response time, ensuring rapid valve opening and closing, and meeting the design target of opening and closing time ≤2s. At the same time, the circumferentially evenly distributed pressure structure ensures that the medium enters the upper and lower balance chambers 83 evenly, avoiding jamming of the piston 7 due to uneven load, and improving the stability of valve operation.

[0052] Compared to existing pneumatic programmable valves, this embodiment has the following advantages: In terms of sealing performance, this embodiment connects the valve stem 3 and the valve disc 61 through an independently set small valve core 5. The valve disc 61 and the small valve core 5 are axially limited by the limiting sleeve 62. With the reserved floating gap H, and the sealing of the floating gap H by the limiting sleeve sealing ring 63 and the small valve core sealing ring 64, the valve disc 61 has the ability to adapt to radial and angular movements. When the valve is closed, it can eliminate the positional deviation caused by the manufacturing precision and assembly error of the parts, and ensure that the valve disc 61 and the valve seat 13 fit evenly around the whole circumference, which greatly improves the sealing reliability. Meanwhile, the valve disc 61 and the small valve core 5 employ a mating structure of a spherical abutment surface 54 and a frustum-shaped conical contact surface 6111. This ensures the smooth self-adaptive effect of the valve disc 61 while enabling automatic centering of the valve disc 61 and the small valve core 5, guaranteeing the coaxiality of the balance channel 51 and the balance hole 611, and preventing abnormal media flow resistance caused by eccentricity. Furthermore, the line contact mating of the spherical and conical surfaces ensures uniform distribution of contact stress, enhancing the structural strength and erosion resistance. Based on this, a composite sealing structure of soft seal + hard seal is adopted, achieving stable fixation through the inclined pressing structure of the pressure ring 66. Combined with the hard alloy reinforced and mirror-finished hard seal end face, zero-leakage sealing can be achieved under harsh operating conditions.

[0053] Regarding motion stability and service life, this embodiment significantly reduces the machining accuracy requirements of the upper pressure hole 71 through the design of the inner groove 73 on the inner wall of the piston 7 and the upper groove 74 on the end face. This ensures that the upper pressure hole 71 can guarantee complete communication between the upper balance chamber 82 and the extension channel 511 within a reasonable assembly error range, eliminating the need to strictly ensure the coaxial alignment of the extension channel 511 and the upper pressure hole 71. This greatly reduces the assembly difficulty of the piston 7 and the small valve core 5, while ensuring that the medium enters the upper balance chamber 82 stably and uniformly from the balance channel 51, so that the amount of medium entering the upper balance chamber 82 per unit time meets the design expectations. In addition to the piston outer sealing ring 78 for dynamic sealing with the sleeve 8, the outer peripheral wall of the piston 7 is also equipped with a PTFE ring 77 for motion guidance, ensuring no metal contact between the piston 7 and the inner wall of the sleeve 8. This avoids wear and jamming between the sleeve 8 and the piston 7 under long-term high-frequency operation, while reducing motion friction resistance, further improving the smoothness of the piston 7's operation and the valve opening and closing response speed. The guide sleeve 23 at valve cover 2 and the oilless bearing 25 provide radial guidance for valve stem 3, forming a double-guide structure for the moving parts of the valve. This significantly improves the centering and stability of the valve stem 3 and piston 7, reduces wear on the inner wall of sleeve 8, piston 7 and various seals under long-term high-frequency operation, and extends the service life of the entire valve.

[0054] For large-size programmable valves with a nominal diameter ≥ DN250, this embodiment uses the travel limiting block 622 on the outer wall of the limiting sleeve 62 and the travel limiting groove 84 on the sleeve 8 to form a mechanical hard limit. Combined with the hard sealing limit between the valve disc 61 and the valve seat 13, and the soft sealing limit between the valve disc sealing ring 67 and the valve seat 13, a multi-limiting structure is formed. This effectively absorbs the inertial impact generated by the rapid opening and closing of heavy moving parts, preventing the failure of a single limiting structure under high-frequency operation, and significantly improving the operational stability and service life of the valve. Simultaneously, the sleeve 8 uses the valve body fixing groove 16 and the valve cover fixing groove 26 to clamp the sleeve limiting block 85 for radial and axial positioning, eliminating the need for additional fixing structures and greatly simplifying the assembly process of the sleeve 8. With the graphite gaskets a on both sides of the sleeve limiting block 85, reliable static sealing can be achieved between the sleeve 8 and the mating surfaces of the valve body 1 and valve cover 2, preventing media leakage. This also absorbs assembly errors and temperature deformation, further improving sealing reliability.

[0055] This invention is not limited to the specific embodiments described above. Those skilled in the art can implement this invention using various other specific embodiments based on the content disclosed herein. Any simple changes or modifications made to the design structure and concept of this invention fall within the protection scope of this invention.

Claims

1. A programmable valve, comprising a valve body, a valve cover, a valve stem, and an actuator, wherein the valve body has a first channel, a second channel, a valve seat, and a connecting channel, the connecting channel connecting the first channel and the second channel, the second channel having a mating hole opposite to the connecting channel, the valve cover covering the opening of the mating hole opposite to the opening of the second channel, and the valve cover being fixedly connected to the valve body by fixing bolts, the valve stem passing through the valve cover, and the actuator being drively connected to the end of the valve stem protruding from the valve body, characterized in that: A small valve core is coaxially fixed to the end of the valve stem away from the actuator. A balance channel, passing through both ends, is coaxially arranged on the small valve core. A flexible sealing assembly, capable of forming a seal with the valve seat, is provided at the end of the small valve core away from the valve stem. The flexible sealing assembly includes a valve disc flexibly connected to the small valve core, and the valve disc has a balance hole coaxially corresponding to the balance channel. A piston is sleeved and fixed on the small valve core. A sleeve is fitted over the piston, and the outer peripheral wall of the piston dynamically seals with the inner wall of the sleeve. A retaining base, surrounding the small valve core, is provided at the end of the sleeve away from the valve cover. The valve cover's end face facing the piston, the piston's end face facing the valve cover, and the inner wall of the sleeve enclose an upper balance cavity. The bottom of the enclosure's end face facing the piston, the piston's bottom face facing the enclosure's bottom, and the inner wall of the sleeve enclose a lower balance cavity. The inner wall of the balance channel is provided with at least two extension channels extending radially along the balance channel. The piston is provided with at least two upper pressure holes connecting the upper balance cavity and the extension channels. The bottom of the enclosure is provided with at least two lower pressure holes connecting the inside and outside of the lower balance cavity. The extension channels, upper pressure holes, and lower pressure holes are all evenly distributed circumferentially around the axis of the balance channel.

2. A programmable valve according to claim 1, characterized in that: The flexible sealing assembly further includes a limiting sleeve, a limiting sleeve sealing ring, and a small valve core sealing ring. The valve disc has an installation groove for inserting the small valve core, and the balance hole is coaxially formed at the bottom of the installation groove. The limiting sleeve is fitted onto the small valve core and positioned between the small valve core and the installation groove. The outer wall of the limiting sleeve is threaded into the inner wall of the installation groove. Limiting sleeve pins are inserted into the limiting sleeve and the valve disc to keep the limiting sleeve and the valve disc relatively fixed. The small valve core has a lower step that can form a limiting position with the end face of the limiting sleeve facing away from the sleeve. The limiting sleeve has an annular sealing groove on its surface facing the axis of the small valve core, and the limiting sleeve sealing ring is disposed in the limiting sleeve sealing groove. The small valve core has a small valve core sealing groove surrounding the balance channel on its surface facing the bottom of the mounting groove, and the small valve core sealing ring is disposed in the small valve core sealing groove. Floating gaps are reserved between the outer wall of the small valve core facing the limiting sleeve and the inner wall of the limiting sleeve, between the surface of the limiting sleeve facing the lower step surface and the lower step surface, and between the outer wall of the small valve core facing the mounting groove and the inner wall of the mounting groove.

3. A programmable valve according to claim 2, characterized in that: The balance hole has a contact surface at the opening of the small valve core. The contact surface is a frustum-shaped cone. The small valve core has an abutment surface on the surface facing the balance hole that abuts against the contact surface. The abutment surface is an arc-shaped spherical surface. The openings of the small valve core sealing groove and the balance channel facing the balance hole are both located on the abutment surface.

4. A programmable valve according to claim 3, characterized in that: The flexible sealing assembly also includes a pressure ring and a valve disc sealing ring. The valve disc has a valve disc limiting groove on its surface facing the valve seat. Both the pressure ring and the valve disc sealing ring are disposed within the valve disc limiting groove. The pressure ring and the valve disc are fixed together by fastening screws. The valve disc sealing ring is located on the side of the pressure ring away from the balance hole. The surfaces of the pressure ring and the valve disc sealing ring that are in contact with each other are inclined surfaces that are away from the bottom of the valve disc limiting groove and in a direction away from the balance hole. The surfaces of the valve disc and the valve seat that are opposite each other are mirror surfaces. The pressure ring and the fastening screws are arranged opposite to the connecting channel, and the valve disc sealing ring is arranged opposite to the valve seat.

5. A programmable valve according to claim 4, characterized in that: The small valve core has a small valve core fixing groove on its end face away from the valve disc. The small valve core fixing groove is coaxially connected to the balance channel. The end of the valve stem away from the actuator is inserted into the small valve core fixing groove and threadedly engaged with it. A valve stem pin is inserted through the outer wall of the small valve core corresponding to the small valve core fixing groove. The outer wall of the small valve core located inside the sleeve has an upper stepped surface. A fixing nut is threadedly fitted onto the small valve core. The two opposite ends of the piston form a limiting fit with the upper stepped surface and the fixing nut, respectively. An inner piston sealing ring is provided between the piston and the upper stepped surface.

6. A programmable valve according to claim 4 or 5, characterized in that: The piston has an annular inner groove on its inner wall, and the extension channel is arranged opposite to the inner groove. The piston has an annular upper groove on its surface facing away from the valve disc. The outer diameter of the fixing nut is between the outer diameter and the inner diameter of the upper groove. The upper groove is close to the inner wall of the small valve core, and its side close to the fixing nut is inclined towards the axis of the small valve core. The two openings of the upper pressure hole are located at the bottom of the inner groove and on the inner wall of the upper groove close to the small valve core, respectively. The piston has an annular piston limiting groove one and an annular piston limiting groove two on its outer peripheral wall. The piston limiting groove one is provided with a PTFE ring, and the piston limiting groove two is provided with a piston outer sealing ring.

7. A programmable valve according to claim 6, characterized in that: The valve cover has an inlet / outlet groove on the surface facing the sleeve for the fixing nut to move axially with the valve stem. The bottom of the inlet / outlet groove facing the upper balance chamber has an assembly groove. A guide sleeve is assembled in the assembly groove. The guide sleeve is fixed to the valve cover by a guide sleeve pin. The side of the valve stem away from the valve disc passes through the guide sleeve and exits the valve cover from the bottom of the assembly groove. An oilless bearing is assembled between the guide sleeve and the valve stem.

8. A programmable valve according to claim 4 or 7, characterized in that: The actuator includes a bracket. The valve cover has a sealing cavity surrounding the valve stem on its side facing the bracket. Inside the sealing cavity, a lower gasket, a V-shaped packing, an upper gasket, a packing gland, and a packing pressure plate are sequentially fitted onto the valve stem in the direction away from the valve disc. The packing pressure plate, the bracket, and the valve cover are fixed by pressure plate bolts. The outer wall of the packing gland has a gland step surface. A butterfly spring is fitted on the packing gland, located between the gland step surface and the packing pressure plate. Multiple V-shaped packings and butterfly springs are provided. Packing gland sealing rings are provided between the outer wall of the packing gland and the valve cover, and between the inner wall of the packing gland and the valve stem.

9. A programmable valve according to claim 8, characterized in that: The outer wall of the limiting sleeve is provided with an annular stroke limiting block. The end face of the stroke limiting block facing away from the valve seat abuts against the end face of the valve disc facing the limiting sleeve. The surface of the enclosing bottom facing the valve disc is provided with a stroke limiting groove that can form a limiting position with the stroke limiting block. The small valve core is coaxially inserted through the bottom of the stroke limiting groove.

10. A programmable valve according to claim 9, characterized in that: The valve body and the valve cover are respectively provided with annular and coaxial valve body fixing groove and valve cover fixing groove on the end face where they abut. The outer wall of the sleeve is provided with annular sleeve limiting block that is simultaneously embedded in the valve body fixing groove and the valve cover fixing groove. Annular graphite gaskets are provided between the sleeve limiting block and the bottom of the valve body fixing groove, and between the sleeve limiting block and the bottom of the valve cover fixing groove.

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