Diaphragm-type fluid flow regulating device

Abstract

This invention discloses a diaphragm-type fluid flow regulating device, comprising a valve body, a valve cover, a valve stem assembly, a pressure cap disposed between the valve body and the valve cover, a diaphragm mounting chamber and a diaphragm disposed between the pressure cap and the valve body, the diaphragm dividing the diaphragm mounting chamber into a working chamber and a clearance chamber, the valve stem assembly for pushing against the diaphragm, and a medium inlet channel and a medium outlet channel communicating with the working chamber on the valve body. The medium inlet channel includes a valve seat mounting section communicating with the working chamber and used for mounting a valve seat assembly, a medium conveying section, and a transition section connecting the valve seat mounting section and the medium conveying section. The valve seat assembly includes a valve seat disposed within the valve seat mounting section and a valve needle penetrating the valve seat and axially movable. The valve seat has an intermediate chamber communicating with the transition section and a medium channel connecting the intermediate chamber and the working chamber. One end of the valve needle abuts against the diaphragm, and the other end can be inserted into the transition section. This invention can achieve high-precision flow regulation under corrosive media.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, and specifically relates to a diaphragm-type fluid flow regulating device. Background Technology

[0002] In the semiconductor industry, high-precision flow control is often required. Related technologies often employ needle valves or diaphragm flow control valves for regulation. Needle valves offer high control precision; however, their internal plastic components and seals have limited sealing performance, and their internal parts can corrode in corrosive media. Diaphragm flow control valves use a diaphragm for isolation, providing good sealing performance and effectively preventing corrosion of internal valve components. However, when the diaphragm is open, it creates an open fluid region between itself and the valve body's medium channel. This fluid region has at least two dimensions: height and width, making precise control difficult. Even with higher-precision drive and control components in some related technologies, it is still impossible to meet the precision flow control requirements when the CV value is less than 0.01. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a diaphragm-type fluid flow regulating device that combines the sealing and isolation advantages of a diaphragm valve with the high-precision regulating characteristics of a needle valve, enabling ultra-fine flow regulation with a CV value of less than 0.01 under corrosive media conditions.

[0004] The diaphragm-type fluid flow regulating device of this invention includes a valve body, a valve cover disposed on the valve body, a valve stem assembly disposed within the valve cover and axially movable, and a pressure cover sandwiched between the valve body and the valve cover. A diaphragm mounting chamber is formed between the pressure cover and the valve body. A diaphragm is disposed within the diaphragm mounting chamber, the edge of which is pressed between the pressure cover and the valve body. The diaphragm divides the diaphragm mounting chamber into a working chamber and a relief chamber. One end of the valve stem assembly passes through the pressure cover and extends into the relief chamber to push against the diaphragm. The valve body has a medium inlet channel and a medium outlet channel communicating with the working chamber. The medium inlet channel includes a section communicating with the working chamber and used for... The valve seat assembly includes a valve seat mounting section, a medium conveying section with one end extending through the side wall of the valve body and the other end for conveying medium toward the working chamber, and a transition section connecting the valve seat mounting section and the medium conveying section. The valve seat assembly includes a valve seat disposed in the valve seat mounting section, a valve needle that penetrates the valve seat and is axially movable, the valve seat having an intermediate chamber communicating with the transition section and a medium channel communicating with the intermediate chamber and the working chamber, the valve needle having two ends protruding from the end face of the valve seat, one end abutting against the diaphragm, and the other end having a tapered structure and being configured to be inserted into the transition section, so as to adjust the medium flow rate by adjusting the gap between the valve needle and the transition section through axial movement of the valve needle.

[0005] The diaphragm-type fluid flow regulating device of this invention integrates a valve seat assembly consisting of a valve seat and a valve needle within the working chamber below the diaphragm. This adjusts the flow regulation channel cross-section to a single-dimensional annular gap between the valve needle's conical structure and the inner wall of the transition section. Furthermore, by driving the diaphragm deformation through the valve stem assembly, the diaphragm pushes the valve needle to move axially, thus linearly changing the flow area of ​​the annular gap. This significantly improves the resolution and accuracy of flow regulation, meeting the precision flow control requirements of a CV value less than 0.01. Simultaneously, the diaphragm completely isolates the area where the valve stem assembly is located from the working medium, preventing corrosive media from eroding the valve stem assembly and internal parts of the valve cover.

[0006] Preferably, the valve seat has an intermediate chamber located near the lower part of the transition section, and a guide hole is formed through the upper part of the intermediate chamber. Multiple media channels are formed around the guide hole. The valve needle includes a guide portion, a limiting portion, and a tapered portion connected in sequence. The free end of the guide portion protrudes from the guide hole, with its end face abutting against the diaphragm. The outer diameter of the limiting portion is larger than the diameter of the guide hole, allowing it to abut against the end face of the guide hole facing the intermediate chamber. The tapered portion has a tapered structure, and its tip is inserted into the transition section. Under the pushing action of the diaphragm, its outer wall surface can seal against the inner wall surface of the outer edge of the transition section to close the media inlet channel.

[0007] Preferably, the diaphragm-type fluid flow regulating device further includes an elastic element, which is disposed on the valve needle and clamped in a compressed state between the limiting part and the bottom wall of the valve seat mounting section, for keeping the valve needle in contact with the valve seat after the valve stem assembly has regulated the flow to stabilize the flow gap between the valve needle and the transition section.

[0008] Preferably, the medium channel is arranged at an angle relative to the central axis of the valve seat, and at least a portion of the inlet end of the medium channel is located outside the outer peripheral wall of the limiting portion to avoid the limiting portion.

[0009] Preferably, the outer peripheral region of the valve seat facing the diaphragm is configured as an inclined structure that gradually moves away from the diaphragm from the inside to the outside relative to the guide hole, and the outlet end of the medium channel is disposed on the inclined structure to avoid contact with the diaphragm so that the intermediate chamber and the working chamber remain in communication.

[0010] Preferably, a plurality of locking blocks are formed on the outer peripheral wall of the end of the valve seat facing the transition section, and a plurality of locking slots are provided at the corresponding positions of the valve seat mounting section, so that the valve seat can be installed by the cooperation of the locking blocks and the locking slots.

[0011] Preferably, the plurality of slots are interconnected through-slot structures, allowing the card block to engage at any angle; Preferably, the valve seat has a telescopic groove between two adjacent locking blocks. The telescopic groove is formed by recessing the end face of the valve seat. The depth of the telescopic groove is greater than the axial thickness of the locking block, so that the locking block can be radially retracted inward to a portion that does not protrude above it, so as to facilitate the assembly of the valve seat.

[0012] Preferably, the outer periphery of one end of the valve seat located in the working chamber has a top surface protrusion, which is pressed against the outer end of the valve seat mounting section to bear the thrust applied by the diaphragm and the valve stem assembly.

[0013] Preferably, the pressure cap has a through hole in the middle, the valve cover has a central channel, and the valve stem assembly includes a top post passing through the through hole and a valve stem body passing through the central channel. One end of the top post facing the diaphragm is placed in the relief cavity and has a flange that abuts against the diaphragm. The diameter of the flange is larger than the diameter of the through hole. The valve stem body includes a first section, a middle section, and a second section connected in sequence. The middle section slides in conjunction with the central channel, and the free end of the second section extends into the through hole and abuts against the other end of the top post. The pressure cap has a groove extending axially along the valve stem assembly, and the second section has a slider that slides in conjunction with the groove, so that the valve stem body can only move axially relative to the pressure cap.

[0014] Preferably, the diaphragm-type fluid flow regulating device further includes a drive assembly for driving the valve stem assembly to move along its own axial direction. The drive assembly includes: an inner sleeve, which is sleeved outside the first section of the valve stem assembly and the two are threadedly connected to form a first threaded engagement portion; an outer sleeve, which is sleeved outside the inner sleeve and drives the inner sleeve to move synchronously, and the outer sleeve is sleeved outside the valve cover, and the outer sleeve and the valve cover are threadedly connected to form a second threaded engagement portion, the second threaded engagement portion having the same rotation direction as the first threaded engagement portion, and the two having a difference in pitch; and an operating part, which is fixedly connected to the outer sleeve so as to screw the outer sleeve through the operating part.

[0015] Preferably, the inner sleeve further includes an adjustment part that extends axially along the inner sleeve to the outside of the outer sleeve, and the end of the adjustment part is provided with an adjustment interface for adjusting the threshold of the medium flow rate.

[0016] The diaphragm-type fluid flow regulating device of this invention combines the advantages of good diaphragm sealing and high precision valve needle adjustment, achieving both corrosion resistance and precise adjustment. Furthermore, the flow regulation accuracy is further improved by using a differential screw sleeve drive assembly. In addition, the elastic element provides pre-tightening force to the valve needle to ensure the stability of the flow output. The snap-fit ​​between the locking block and the locking slot simplifies the assembly process of the valve seat and valve stem assembly. The flow threshold is set through the adjustment part. Attached Figure Description

[0017] Figure 1 This is a front cross-sectional view of the present invention.

[0018] Figure 2 This is a partial front sectional view of the present invention.

[0019] Figure 3This is a front cross-sectional view of the valve seat of the present invention (open state).

[0020] Figure 4 This is a front sectional view of the valve seat of the present invention (closed state).

[0021] Figure 5 This is a perspective view of the valve seat of the present invention.

[0022] Figure 6 This is a perspective view of the valve needle of the present invention.

[0023] Figure 7 This is a front cross-sectional view of the valve stem assembly and diaphragm of the present invention.

[0024] Figure label: 1. Valve body; 11. Medium inlet channel; 111. Valve seat mounting section; 1111. Slot; 112. Medium conveying section; 113. Transition section; 12. Medium outlet channel; 14. Inspection hole; 15. Annular protrusion; 2. Valve cover; 21. Central channel; 22. First valve cover step; 23. Second valve cover step; 24. Second limiting element; 3. Valve stem assembly; 31. Top post; 311. Flange; 32. Valve stem body; 321. First section; 322. Middle section; 323. Second section; 324. Slider; 325. First valve stem step; 326. Second valve stem step; 4. Pressure cap; 41. Through hole; 43. Slide groove; 5. Diaphragm mounting chamber; 51. Working chamber; 52. Relief chamber; 6. Diaphragm; 61. Depression; 62. Protrusion; 7. Valve seat assembly; 71. Valve seat; 711. Intermediate chamber; 712. Medium passage; 713. Guide hole; 714. Inclined structure; 715. Locking block; 716. Top surface protrusion; 717. Telescopic groove; 72. Valve needle; 721. Guide part; 722. Limiting part; 723. Conical part; 9. Elastic components; 10. Drive assembly; 101. Inner sleeve; 1011. Adjustment part; 1012. First limiting member; 102. Outer sleeve; 1021. First inner cavity; 1022. Second inner cavity; 1023. Sleeve step part; 103. Operating part; 104. First threaded mating part; 105. Second threaded mating part. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. 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.

[0026] like Figures 1-7 As shown, the diaphragm-type fluid flow regulating device of this invention includes a valve body 1, a valve cover 2 disposed on the valve body 1, a valve stem assembly 3 disposed in the valve cover 2 and axially movable, and a pressure cover 4 sandwiched between the valve body 1 and the valve cover 2. A diaphragm mounting chamber 5 is formed between the pressure cover 4 and the valve body 1. A diaphragm 6 is disposed in the diaphragm mounting chamber 5. The edge of the diaphragm 6 is pressed between the pressure cover 4 and the valve body 1, and the diaphragm 6 divides the diaphragm mounting chamber 5 into a working chamber 51 and a relief chamber 52. One end of the valve stem assembly 3 passes through the pressure cover 4 and extends into the relief chamber 52 to push against the diaphragm 6. A medium inlet channel 11 and a medium outlet channel 12 communicating with the working chamber 51 are provided on the valve body 1. The medium inlet channel 11 includes a valve seat mounting section 111 connected to the working chamber 51 and used for mounting the valve seat assembly 7, a medium conveying section 112 extending through the side wall of the valve body 1 at one end and used for conveying medium toward the working chamber 51 at the other end, and a transition section 113 connecting the valve seat mounting section 111 and the medium conveying section 112. The valve seat assembly 7 includes a valve seat 71 disposed in the valve seat mounting section 111 and a valve needle 72 that penetrates the valve seat 71 and is axially movable. The valve seat 71 has an intermediate chamber 711 connected to the transition section 113 and a medium channel 712 connecting the intermediate chamber 711 and the working chamber 51. The two ends of the valve needle 72 are respectively protruding from the end face of the valve seat 71. One end of the needle abuts against the diaphragm 6, and the other end is a conical structure and is configured to be inserted into the transition section 113 so as to adjust the medium flow rate by adjusting the gap between the valve needle 72 and the transition section 113 through axial movement of the valve needle 72.

[0027] In this embodiment, by integrating the valve seat assembly 7 into the working chamber 51 below the diaphragm 6, the valve stem assembly 3 drives the diaphragm 6 to deform and push the valve needle 72 to move axially. This causes a change in the annular gap between the tapered structure at the end of the valve needle 72 and the transition section 113. Compared to traditional diaphragm valves that form an open fluid region with both height and width dimensions between the diaphragm 6 and the medium channel 712, the flow regulation channel section control of this device only involves the annular gap between the tapered structure of the valve needle 72 and the inner wall of the transition section 113. This significantly improves the regulation accuracy and can meet the precision flow control requirements of a CV value of less than 0.01. At the same time, the diaphragm 6 completely isolates the area where the valve stem assembly 3 is located from the medium, preventing corrosive media from eroding the valve stem assembly 3 and other upper parts.

[0028] Specifically, see Figure 1-2As shown, the shape of the medium inlet channel 11 can be designed as needed to accommodate VCR or IGS interfaces. For example, it can be generally L-shaped, including a medium delivery section 112 extending horizontally, a transition section 113 extending vertically, and a valve seat mounting section 111 located above the transition section 113. In one specific arrangement, one end of the medium delivery section 112 extends through the side wall of the valve body 1 (the left side wall shown in the attached figure) to connect to an external medium source, while the other end (the right end shown in the attached figure) extends towards the interior of the valve body 1 and communicates with the lower end of the transition section 113. The transition section 113 extends vertically, and its upper end communicates with the valve seat mounting section 111. The valve seat mounting section 111 is located directly above the transition section 113, and its diameter is larger than that of the transition section 113, used to accommodate and mount the valve seat assembly 7. The diameter of the transition section 113 is typically small to reduce the pressure of the medium and facilitate control by the valve needle 72. The length of the transition section 113 should not be too long or too short, aiming to balance ease of processing and linearity of flow regulation. Additionally, one end of the medium outflow channel 12 (the upper end shown in the attached figure) is connected to the working chamber 51, and the other end extends through the side wall of the valve body 1 (the right side wall shown in the attached figure).

[0029] The valve seat assembly 7 is installed within the valve seat mounting section 111. The valve seat 71 has an intermediate chamber 711 inside, which is directly connected to the transition section 113. A medium passage 712 is also provided on the valve seat 71, connecting the intermediate chamber 711 and the working chamber 51. When the medium enters from the medium conveying section 112, it passes through the transition section 113 into the intermediate chamber 711, then through the medium passage 712 into the working chamber 51, and finally exits from the medium outflow passage 12. The valve needle 72 penetrates the valve seat 71, with its lower end inserted into the transition section 113 and its upper end abutting against the diaphragm 6. When the valve stem assembly 3 pushes the diaphragm 6 downwards, the diaphragm 6 deforms and pushes the valve needle 72 downwards, reducing the gap between the conical structure of the valve needle 72 and the inner wall of the transition section 113, thus reducing the flow rate. When the outer wall surface of the conical structure of the valve needle 72 seals against the inner wall surface of the outer edge of the transition section 113, the medium inflow passage 11 is completely closed. When the valve stem assembly 3 retracts upward, the diaphragm 6 resets under its own elasticity, and the valve needle 72 also moves upward under the action of the medium pressure, increasing the gap and the flow rate.

[0030] Preferably, the valve body 1 is further provided with a detection hole 14, which is located on the side of the diaphragm 6 facing the relief chamber 52. The detection hole 14 penetrates the side wall of the valve body 1 and is used for external leakage performance testing after the entire device is assembled. If leakage occurs during the testing process, the test medium will seep out through the detection hole 14, making it easy for operators to detect in a timely manner.

[0031] Preferably, the valve body 1 is provided with an annular protrusion 15 corresponding to the edge of the diaphragm 6 and protruding towards the diaphragm 6. The diaphragm 6 is pressed between the annular protrusion 15 and the gland 4. The cross-sectional area of ​​the annular protrusion 15 gradually decreases along the direction towards the diaphragm 6, that is, the side of the annular protrusion 15 facing the diaphragm 6 has a pointed structure, and the end of the pointed structure can be provided with a rounded chamfer. The small-plane seal between the pointed end of the annular protrusion 15 and the edge area of ​​the diaphragm 6 is achieved through the elastic deformation, which can enhance the sealing effect of the edge of the diaphragm 6 and prevent the medium in the working chamber 51 from leaking from the edge of the diaphragm 6.

[0032] In some embodiments, see Figure 1-4 As shown, an intermediate chamber 711 is provided inside the valve seat 71 near the lower part of the transition section 113. A guide hole 713 is provided through the upper part of the intermediate chamber 711, and multiple media channels 712 are provided around the guide hole 713. The valve needle 72 includes a guide part 721, a limiting part 722, and a conical part 723 connected in sequence. The free end of the guide part 721 protrudes from the guide hole 713, so that its end face abuts against the diaphragm 6; the outer diameter of the limiting part 722 is larger than the diameter of the guide hole 713, so that it can abut against the end face of the guide hole 713 facing the intermediate chamber 711; the conical part 723 has a conical structure, and the tip of the conical structure is inserted into the transition section 113. Under the pushing action of the diaphragm 6, its outer wall surface can seal against the inner wall surface of the outer edge of the transition section 113 to close the media inlet channel 11.

[0033] In this embodiment, the guide hole 713 provides precise guidance for the axial movement of the valve needle 72. The fit between the limiting part 722 and the end face of the guide hole 713 limits the maximum stroke of the valve needle 72 moving upward. At the same time, multiple media channels 712 are distributed around the guide hole 713, so that the media can flow evenly from the intermediate chamber 711 into the working chamber 51, ensuring the stability of the media flow.

[0034] Furthermore, a clearance fit is adopted between the inner wall surface of the guide hole 713 and the outer peripheral surface of the guide portion 721. The clearance size ensures both guiding accuracy and smooth axial movement of the valve needle 72. The inner wall surface of the guide hole 713 can be precision ground or polished to reduce frictional resistance. The guide portion 721 is preferably cylindrical.

[0035] The outer diameter of the limiting part 722 is larger than the diameter of the guide hole 713. When the diaphragm 6 moves upward and rebounds, the limiting part 722 can abut against the side end face of the guide hole 713 facing the intermediate chamber 711, preventing the valve needle 72 from moving too upward and coming out of the valve seat 71. At the same time, it limits the upper dead point of the valve needle 72's stroke, which is the maximum medium flow gap at this time.

[0036] The taper of the conical portion 723 is designed according to the flow adjustment range and accuracy requirements. A larger taper results in a greater change in the annular gap area corresponding to a unit axial displacement of the valve needle 72, leading to higher flow adjustment sensitivity; a smaller taper results in a smaller change in area corresponding to a unit displacement, leading to higher adjustment accuracy. As an example, the taper angle of the conical portion 723 can be selected within the range of 10 to 60 degrees. The tip diameter of the conical structure is smaller than the inner diameter of the upper opening of the transition section 113, ensuring that the valve needle 72 can be inserted into the transition section 113. The conical portion 723 is preferably a conical structure, and the corresponding upper opening of the transition section 113 is also circular, facilitating processing and creating an annular flow gap that allows for smoother medium flow.

[0037] Regarding the stroke of the valve needle 72, the distance between the limiting part 722 and the end face of the intermediate chamber 711 facing the guide hole 713 limits the maximum upward stroke of the valve needle 72, i.e., the upper dead point of the valve needle 72. The maximum downward stroke of the valve needle 72 corresponds to the state where the outer peripheral surface of the tapered part 723 and the inner wall surface of the outer edge of the transition section 113 are in sealing contact. At this time, the upper end face of the guide part 721 can be approximately flush with the upper end face of the valve seat 71 to ensure that the diaphragm 6 is not subjected to excessive downward thrust when the valve needle 72 is closed.

[0038] In some embodiments, the diaphragm-type fluid flow regulating device further includes an elastic element 9, which is disposed on the valve needle 72 and clamped in a compressed state between the limiting portion 722 and the bottom wall of the valve seat mounting section 111, for keeping the valve needle 72 in contact with the valve seat 71 after the valve stem assembly 3 has regulated the flow, so as to stabilize the flow gap between the valve needle 72 and the transition section 113.

[0039] The elastic element 9 provides an upward preload to the valve needle 72, ensuring that the limiting portion 722 of the valve needle 72 always tends to conform to the end face of the guide hole 713. Therefore, after the valve stem assembly 3 completes one flow regulation action, the valve needle 72 can quickly return to its original position following the rebound of the diaphragm 6 and maintain its position, thus making the annular gap between the valve needle 72 and the transition section 113 more stable. This avoids fluctuations in medium flow caused by vibration, etc.

[0040] Furthermore, the elastic element 9 is preferably a cylindrical helical spring, made of a material with good corrosion resistance, suitable for various corrosive media conditions. The elastic element 9 is sleeved on the outside of the tapered portion 723 of the valve needle 72, with one end abutting against the lower end face of the limiting portion 722, and the other end abutting against the bottom wall of the valve seat mounting section 111.

[0041] In some embodiments, the medium channel 712 is arranged at an angle relative to the central axis of the valve seat 71, and at least a portion of the inlet end of the medium channel 712 is located outside the outer peripheral wall of the limiting portion 722 to avoid the limiting portion 722.

[0042] Specifically, the distance between the upper end of the medium channel 712 and the central axis is greater than the distance between the lower end of the medium channel 712 and the central axis. This makes the thickness between the medium channel 712 and the outer circumferential surface of the valve seat 71 gradually increase from top to bottom after the medium channel 712 is opened in the valve seat 71, so as to maximize the strength of the valve seat 71 within the limited volume of the valve seat 71.

[0043] In addition, the inlet end of the medium channel 712 can be offset outward to the radially outer region of the outer peripheral wall of the limiting part 722 to prevent the limiting part 722 from blocking the inlet end of the medium channel 712, so that the medium can flow smoothly from the intermediate chamber 711 into the working chamber 51 through the medium channel 712.

[0044] As a preferred example, the number of media channels 712 is two, and the two media channels 712 are evenly distributed around the central axis of the valve seat 71. Each media channel 712 is arranged inclined outward relative to the central axis of the valve seat 71 to ensure the circumferential uniformity of the media flow. In practical applications, more than two media channels 712 can also be set to be evenly distributed.

[0045] In some embodiments, the outer peripheral region of the valve seat 71 facing the diaphragm 6 is configured as an inclined structure 714 that gradually moves away from the diaphragm 6 relative to the guide hole 713 from the inside to the outside. The outlet end of the medium channel 712 is disposed on the inclined structure 714 to avoid contact with the diaphragm 6, so that the intermediate chamber 711 and the working chamber 51 remain in communication.

[0046] The inclined structure 714 positions the outlet end of the medium channel 712 at a lower position relative to the upper end face of the guide hole 713. When the diaphragm 6 deforms downward under the pressure of the medium or the drive of the valve stem assembly 3, the lower surface of the diaphragm 6 may adhere to the upper end face of the valve seat 71. If the outlet end of the medium channel 712 is located on a plane parallel to the diaphragm 6, the diaphragm 6 may block the outlet end when it adheres, causing the intermediate chamber 711 to be isolated from the working chamber 51. However, by arranging the outlet end on the inclined structure 714, even if the diaphragm 6 adheres to the area around the guide hole 713, the outlet end on the inclined structure 714 can still maintain a gap with the diaphragm 6, ensuring that the intermediate chamber 711 and the working chamber 51 are always connected, and the medium can continuously flow out from the medium channel 712.

[0047] Preferably, the inclined structure 714 is an annular conical surface arranged around the central axis of the valve seat 71, and its cone angle (i.e., the angle between the inclined surface and the plane perpendicular to the central axis) is between 5 degrees and 20 degrees. The outlet ends of multiple media channels 712 are evenly distributed on this annular conical surface.

[0048] In some embodiments, a plurality of locking blocks 715 are formed on the outer peripheral wall of the valve seat 71 facing the transition section 113, and a plurality of locking slots 1111 are provided at the corresponding positions of the valve seat mounting section 111. The valve seat 71 is installed by the cooperation of the locking blocks 715 and the locking slots 1111.

[0049] The snap-fitting mechanism between the locking block 715 and the locking groove 1111 makes the installation and disassembly of the valve seat 71 simple and quick, without the need for additional fasteners, and can reliably position the valve seat 71 in the axial direction, preventing the valve seat 71 from moving axially during operation.

[0050] Further, see Figure 5 As shown, multiple retaining blocks 715 are evenly distributed circumferentially along the valve seat 71. Each retaining block 715 protrudes outward from the outer peripheral wall of the bottom of the valve seat 71, and its axial thickness is determined according to the overall dimensions of the valve seat 71 and the stress requirements. Retaining grooves 1111 are formed on the inner wall surface of the valve seat mounting section 111, and the shape of the retaining grooves 1111 matches the shape of the retaining blocks 715. As a preferred example, the number of retaining blocks 715 is three or four, and correspondingly, the number of retaining grooves 1111 is the same as the number of retaining blocks 715.

[0051] In some embodiments, the plurality of slots 1111 are interconnected through slot structures, which engage the card block 715 at any angle.

[0052] The interconnected through-slot structure connects multiple slots 1111 into a continuous annular groove area, so that the valve seat 71 does not need to be aligned with a specific circumferential angle during installation. The locking block 715 can be locked into the through slot at any circumferential angle position, which greatly reduces the assembly difficulty and improves the assembly efficiency.

[0053] In some embodiments, the valve seat 71 is provided with a telescopic groove 717 between two adjacent locking blocks 715. The telescopic groove 717 is formed by recessing from the end face of the valve seat 71. The depth of the telescopic groove 717 is greater than the axial thickness of the locking block 715, so that the locking block 715 can be radially retracted inward to not protrude from the outer peripheral wall of the valve seat 71 above the locking block 715, so as to facilitate the assembly of the valve seat 71.

[0054] The expansion groove 717 thins the wall of the valve seat 71 between adjacent locking blocks 715, forming a cantilever structure with a certain degree of elasticity. Preferably, the expansion groove 717 completely penetrates the side wall of the valve seat 71 and communicates with the intermediate chamber 711. During the process of axially pushing the valve seat 71 into the valve seat mounting section 111, the locking block 715 is radially compressed by the inner wall of the valve seat mounting section 111, allowing the outer peripheral surface of the locking block 715 to retract inward until it does not protrude beyond the outer peripheral wall of the valve seat 71 above the locking block 715. This allows the lower end of the valve seat 71 to pass smoothly through the smaller diameter area in the valve seat mounting section 111. When the locking block 715 reaches the locking groove 1111, the locking block 715 pops outward under the elastic action of the material and locks into the locking groove 1111, completing the assembly.

[0055] Furthermore, the telescopic groove 717 extends along the axial direction of the valve seat 71, and the extension dimension is greater than the dimension of the locking block 715 along the axial direction of the valve seat 71, thereby improving the elasticity of the locking block 715 and facilitating the installation of the valve seat 71.

[0056] In some embodiments, a top surface protrusion 716 is formed on the outer periphery of one end of the valve seat 71 located in the working chamber 51. The top surface protrusion 716 is pressed against the outer end of the valve seat mounting section 111 to bear the thrust applied by the diaphragm 6 and the valve stem assembly 3.

[0057] The top surface protrusion 716 transmits the axial force borne by the valve seat 71 to the upper end face of the valve seat mounting section 111, so that the axial bearing path of the valve seat 71 is located in the upper region of the valve seat 71. The bottom end of the valve seat 71 may not bear the axial force, or there may be a gap between the bottom end of the valve seat 71 and the bottom of the valve seat mounting section 111, that is, the bottom end of the valve seat 71 is slightly suspended. Due to the design of the intermediate chamber 711 inside the valve seat 71, as well as the locking block 715, the expansion groove 717, etc., the bottom strength of the valve seat 71 is relatively weak. This arrangement means that the valve seat 71 only bears the force at the top through the top surface protrusion 716, avoiding deformation or creep under long-term pressure due to the relatively soft bottom of the valve seat 71 caused by the thin wall thickness, which is beneficial to maintaining the dimensional stability of the internal structure of the valve seat 71.

[0058] Furthermore, the top surface protrusion 716 extends continuously along the circumference of the valve seat 71 to form an annular flange, and its lower surface is a plane to form a surface contact with the upper end surface of the valve seat mounting section 111.

[0059] In some embodiments, the pressure cap 4 has a through hole 41 in the middle, the valve cover 2 has a central channel 21, and the valve stem assembly 3 includes a top post 31 passing through the through hole 41 and a valve stem body 32 passing through the central channel 21. The end of the top post 31 facing the diaphragm 6 is placed in the relief chamber 52 and has a flange 311 that abuts against the diaphragm 6. The diameter of the flange 311 is larger than the diameter of the through hole 41. The valve stem body 32 includes a first section 321, a middle section 322, and a second section 323 connected in sequence. The middle section 322 is slidably engaged with the central channel 21, and the free end of the second section 323 extends into the through hole 41 and abuts against the other end of the top post 31. The pressure cap 4 has a groove 43 extending axially along the valve stem assembly 3, and the second section 323 has a slider 324 that is slidably engaged in the groove 43, so that the valve stem body 32 can only move axially relative to the pressure cap 4.

[0060] In this embodiment, the axial movement of the valve stem body 32 is transmitted to the top post 31 through the separate design of the top post 31 and the valve stem body 32. Then, the flange 311 of the top post 31 pushes the diaphragm 6 to deform. The diameter of the flange 311 is larger than the diameter of the through hole 41, ensuring that the top post 31 will not come out of the through hole 41. At the same time, the cooperation between the slide groove 43 and the slider 324 restricts the circumferential rotation of the valve stem body 32, allowing it to move only axially, thus providing the necessary circumferential constraint for the differential threaded transmission of the drive assembly 10.

[0061] Further, see Figure 1 and Figure 7 As shown, the clearance chamber 52 has a stepped two-section internal structure. The larger diameter section accommodates the upward arching portion of the diaphragm 6 during deformation, providing ample clearance space for the diaphragm 6. The smaller diameter section is located above and accommodates the flange 311 of the top post 31. There is a gap between the upper end face of the flange 311 and the top wall surface of the clearance chamber 52. This gap limits the maximum upward stroke of the top post 31 and the diaphragm 6, i.e., the upper stop point of the top post 31. When the diaphragm 6 returns to its original position under its own elastic force, the upper end face of the flange 311 abuts against the top wall surface of the clearance chamber 52, preventing the top post 31 from moving excessively upward.

[0062] Furthermore, the diaphragm 6 has a recessed portion 61 in the middle, and protrusions 62 are provided around the recessed portion 61. The recessed portion 61 mates with the end face of the flange 311, and the recessed portion 61 is concave towards the valve seat assembly 7, while the protrusions 62 protrude towards the valve stem assembly 3. The recessed portion 61 and the protrusions 62 are transitioned by an arc structure. When the lower end face of the flange 311 pushes against the diaphragm 6, the end face of the flange 311 mates with the recessed portion 61, ensuring that the flange 311 and the diaphragm 6 have a large contact area, while the protrusions 62 provide the material allowance required for the deformation of the diaphragm 6.

[0063] Preferably, the outer diameter of the middle section 322 of the valve stem body 32 is larger than the outer diameter of either the first section 321 or the second section 323, so that the middle section 322 and the central channel 21 have sufficient sliding contact area to ensure the axial movement stability and guiding accuracy of the valve stem body 32. A first valve stem step 325 is formed between the first section 321 and the middle section 322, and a second valve stem step 326 is formed between the middle section 322 and the second section 323. When the valve stem body 32 moves toward the valve body 1 (moves downward), the second valve stem step 326 can abut against the side (upper side) of the gland 4 away from the valve body 1, forming the lower dead point of the valve stem body 32's stroke, which corresponds to the maximum downward stroke of the diaphragm 6.

[0064] The side of the slide groove 43 facing away from the valve body 1 is open, allowing the slider 324 to disengage from the slide groove 43 along this opening for easy assembly and maintenance. In one specific implementation, the slider 324 is constructed as a pin, with a radial pin hole on the second section 323. The pin is installed in the pin hole and extends into the corresponding slide groove 43.

[0065] In some embodiments, the diaphragm-type fluid flow regulating device further includes a drive assembly 10, which drives the valve stem assembly 3 to move axially. The drive assembly 10 includes an inner sleeve 101, an outer sleeve 102, and an operating part 103. The inner sleeve 101 is sleeved on the outside of the first segment 321 of the valve stem assembly 3, and the two are threadedly connected to form a first threaded engagement portion 104. The outer sleeve 102 is sleeved on the outside of the inner sleeve 101 and drives the inner sleeve 101 to move synchronously. The outer sleeve 102 is sleeved on the outside of the valve cover 2, and the outer sleeve 102 and the valve cover 2 are threadedly connected to form a second threaded engagement portion 105. The second threaded engagement portion 105 has the same direction of rotation as the first threaded engagement portion 104, and the pitch of the two has a difference. The operating part 103 is fixedly connected to the outer sleeve 102 so that the outer sleeve 102 can be screwed on by the operating part 103.

[0066] The aforementioned drive assembly 10 employs a differential thread principle to achieve high-precision micro-displacement output. The outer sleeve 102 and inner sleeve 101 are fixedly fitted together to form an integral differential threaded sleeve. Tightening the operating part 103 drives the integral differential threaded sleeve to rotate. On one hand, the outer sleeve 102 generates axial displacement relative to the fixed valve cover 2 through the second threaded mating part 105; on the other hand, the inner sleeve 101 rotates synchronously with the differential threaded sleeve, driving the valve stem assembly 3, which is restricted from circumferential rotation, through the first threaded mating part 104. Since the first threaded mating part 104 and the second threaded mating part 105 have the same direction of rotation but different pitches, the two axial movements cancel each other out, causing the valve stem assembly 3 to output a small axial displacement equal to the difference in the pitches of the two threads, thereby achieving high-precision micro-flow regulation of the diaphragm valve.

[0067] The working principle of the differential sleeve can be understood as follows: Consider the outer sleeve 102 and the inner sleeve 101 as a single, integral sleeve rotating around the valve cover 2 (the two are fixed in place). As this integral sleeve rotates one revolution, on one hand, the outer sleeve 102 generates a first axial displacement 321 (e.g., 0.45 mm) on the valve cover 2 through the second threaded engagement part 105, causing the entire sleeve to move synchronously in that direction. On the other hand, the inner sleeve 101 rotates synchronously with the sleeve, driving the circumferentially constrained valve stem assembly 3 through the first threaded engagement part 104, causing the valve stem assembly 3 to generate a second axial displacement 323 (e.g., 0.5 mm) relative to the inner sleeve 101, and the direction of the second axial displacement 323 is opposite to the direction of the first axial displacement 321. After the two displacements cancel each other out, the actual net displacement obtained by the valve stem assembly 3 is only the difference in pitch between the two, i.e., 0.5 mm - 0.45 mm = 0.05 mm. In other words, when the operating part 103 rotates a full circle, the valve stem assembly 3 moves only 0.05mm axially, achieving extremely high adjustment resolution and precision.

[0068] Furthermore, the operating part 103 is constructed as a cylindrical structure, fitted onto the outside of the outer sleeve 102, and the two are fixedly connected by a pin. The operating part 103 may be equipped with a dial, and the valve cover 2 is equipped with an indicator arrow. Through the cooperation of the dial and the indicator arrow, the operator can easily read the current flow adjustment position, realizing quantitative adjustment and repeatable positioning.

[0069] Regarding stroke limitation, the outer circumferential surface of the valve cover 2 is provided with a first valve cover step 22. When the outer sleeve 102 moves toward the valve body 1, it can abut against the first valve cover step 22, forming one of the lower stop points of the outer sleeve 102. The inner wall surface of the outer sleeve 102 has a first inner cavity 1021 and a second inner cavity 1022 that are interconnected. The diameter of the second inner cavity 1022 is larger than the diameter of the first inner cavity 1021. The first inner cavity 1021 is fitted onto the outside of the inner sleeve 101 and fixedly engaged with it. The second inner cavity 1022 is fitted onto the outer circumferential surface of the valve cover 2 and threadedly engaged with the valve cover 2. A sleeve step 1023 is formed between the first inner cavity 1021 and the second inner cavity 1022. When the outer sleeve 102 moves downward, the sleeve step 1023 can abut against the end of the pressure cap 4 away from the valve body 1, forming another lower stop point of the outer sleeve 102. By limiting the axial movement range of the outer sleeve 102, damage to parts caused by excessive tightening is prevented.

[0070] One end of the inner sleeve 101 is housed within the central channel 21 of the valve cover 2, and a first limiting member 1012 is provided at this end. The outer peripheral surface of the first limiting member 1012 is slidably engaged with the inner peripheral surface of the central channel 21. A second limiting member 24 is provided at the end of the valve cover 2 away from the valve body 1. The first limiting member 1012 can reciprocate between the second limiting member 24 and the first valve stem step 325, thereby limiting the axial travel range of the inner sleeve 101.

[0071] After the operating part 103 moves downward toward one side of the valve body 1, it can abut against the second valve cover step 23 provided on the valve cover 2, forming the lower stop point of the operating part 103. The above-mentioned stroke limits are coordinated with each other and designed with the stroke of the valve needle 72 as the reference stroke. The axial stroke of each component meets the requirements of the reference stroke of the valve needle 72. For example, the moving stroke of the diaphragm 6 and the inner sleeve 101 is greater than or equal to the reference stroke of the valve needle 72. The required moving stroke of the outer sleeve 102 is further calculated by the pitch difference between the first threaded mating part 104 and the second threaded mating part 105, which is the final moving stroke of the operating part 103.

[0072] In some embodiments, the inner sleeve 101 further includes an adjustment portion 1011, which extends axially along the inner sleeve 101 to the outside of the outer sleeve 102. The end of the adjustment portion 1011 is provided with an adjustment interface for adjusting the threshold value of the medium flow rate.

[0073] The adjustment unit 1011 is used to independently adjust the initial circumferential angle between the inner sleeve 101 and the outer sleeve 102. That is, when the operating unit 103 is at zero position, the valve needle 72 is at its minimum gap in the initial state and the transition section 113, or when the operating unit 103 is at its maximum rotation angle, the valve needle 72 is at its maximum gap in the initial state and the transition section 113, thereby setting the minimum threshold and the maximum threshold of the medium flow rate.

[0074] Furthermore, the adjusting part 1011 can be formed by extending upward from the body of the inner sleeve 101, that is, it is an integral structure with the inner sleeve 101. The adjusting interface provided at the end of the adjusting part 1011 can be in the form of internal hexagonal interface, external hexagonal interface, slotted slot or cross slot, etc., so as to facilitate the use of tools such as wrenches or screwdrivers for tightening operations.

[0075] In some specific embodiments, the inner sleeve 101 and the outer sleeve 102 are fixedly connected by clamping bolts. During normal use, the clamping bolts are locked, and there is no relative rotation between the inner sleeve 101 and the outer sleeve 102; they rotate synchronously. When it is necessary to adjust the flow threshold using the adjusting part 1011, the clamping bolts are loosened, allowing the inner sleeve 101 to rotate independently relative to the outer sleeve 102. By turning the adjusting interface of the adjusting part 1011 with a tool, the initial circumferential angle between the inner sleeve 101 and the outer sleeve 102 is changed, thereby changing the initial axial position of the valve stem assembly 3 at the zero position, and consequently changing the initial gap between the valve needle 72 and the transition section 113. After adjustment, the clamping bolts are retightened, and the inner sleeve 101 and the outer sleeve 102 return to their fixed synchronous rotation relationship.

[0076] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0077] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0078] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0079] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0080] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0081] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A diaphragm-type fluid flow regulating device, comprising a valve body, a valve cover disposed on the valve body, a valve stem assembly disposed within the valve cover and axially movable, and a pressure cover sandwiched between the valve body and the valve cover, wherein a diaphragm mounting chamber is formed between the pressure cover and the valve body, a diaphragm is disposed within the diaphragm mounting chamber, the edge of the diaphragm is pressed between the pressure cover and the valve body, and the diaphragm divides the diaphragm mounting chamber into a working chamber and a relief chamber; one end of the valve stem assembly passes through the pressure cover and extends into the relief chamber to abut against the diaphragm; the valve body has a medium inlet channel and a medium outlet channel communicating with the working chamber, characterized in that: The medium inlet channel includes a valve seat mounting section connected to the working chamber and used for mounting the valve seat assembly, a medium conveying section with one end extending through the side wall of the valve body and the other end used for conveying the medium toward the working chamber, and a transition section connecting the valve seat mounting section and the medium conveying section. The valve seat assembly includes a valve seat disposed within the valve seat mounting section and a valve needle that penetrates the valve seat and is axially movable. The valve seat has an intermediate chamber communicating with the transition section and a medium channel connecting the intermediate chamber and the working chamber. The two ends of the valve needle protrude from the end face of the valve seat, one end of which abuts against the diaphragm, and the other end is a tapered structure and is configured to be inserted into the transition section, so as to adjust the medium flow rate by adjusting the gap between the valve needle and the transition section through axial movement of the valve needle.

2. The diaphragm-type fluid flow regulating device according to claim 1, characterized in that, The valve seat has an intermediate chamber located at the lower part near the transition section. A guide hole is provided above the intermediate chamber, and multiple media channels are provided around the guide hole. The valve needle includes a guide portion, a limiting portion, and a tapered portion connected in sequence. The free end of the guide portion protrudes from the guide hole, so that its end face abuts against the diaphragm; The outer diameter of the limiting part is larger than the diameter of the guide hole, so that it can abut against the side end face of the guide hole facing the intermediate cavity; The conical part has a conical structure, and the tip of the conical structure is inserted into the transition section. Under the pushing action of the diaphragm, its outer wall surface can seal against the inner wall surface of the outer edge of the transition section to close the medium entry channel.

3. The diaphragm-type fluid flow regulating device according to claim 2, characterized in that, It also includes an elastic element, which is disposed on the valve needle and clamped in a compressed state between the limiting part and the bottom wall of the valve seat mounting section, for keeping the valve needle in contact with the valve seat after the valve stem assembly has adjusted the flow rate, so as to stabilize the flow gap between the valve needle and the transition section. And / or, the medium channel is arranged at an angle relative to the central axis of the valve seat, and at least a portion of the inlet end of the medium channel is located outside the outer peripheral wall of the limiting portion to avoid the limiting portion.

4. The diaphragm-type fluid flow regulating device according to claim 2, characterized in that, The outer peripheral area of ​​the valve seat facing the diaphragm is configured as an inclined structure that gradually moves away from the diaphragm from the inside to the outside relative to the guide hole. The outlet end of the medium channel is located on the inclined structure to avoid contact with the diaphragm, thereby keeping the intermediate chamber and the working chamber in communication.

5. The diaphragm-type fluid flow regulating device according to claim 1, characterized in that, Multiple locking blocks are formed on the outer peripheral wall of the valve seat facing the transition section, and multiple locking slots are provided at the corresponding positions of the valve seat mounting section. The valve seat is installed by the cooperation of the locking blocks and the locking slots.

6. The diaphragm-type fluid flow regulating device according to claim 5, characterized in that, The multiple slots are interconnected through-slot structures, allowing the card block to engage at any angle; And / or, the valve seat is provided with a telescopic groove between two adjacent locking blocks, the telescopic groove being recessed from the end face of the valve seat, the depth of the telescopic groove being greater than the axial thickness of the locking block, so that the locking block can be radially retracted inward to a portion that does not protrude above it, so as to facilitate the assembly of the valve seat.

7. The diaphragm-type fluid flow regulating device according to claim 1, characterized in that, The valve seat has a top surface protrusion formed on the outer periphery of one end located in the working chamber. The top surface protrusion is pressed against the outer end of the valve seat mounting section to bear the thrust applied by the diaphragm and the valve stem assembly.

8. The diaphragm-type fluid flow regulating device according to claim 1, characterized in that, The pressure cap has a through hole in the middle, the valve cover has a central channel, and the valve stem assembly includes a top post passing through the through hole and a valve stem body passing through the central channel. The top post is placed in the relief chamber at one end facing the diaphragm and has a flange that abuts against the diaphragm. The diameter of the flange is larger than the diameter of the through hole. The valve stem body includes a first section, a middle section and a second section connected in sequence. The middle section slides with the central channel. The free end of the second section extends into the through hole and abuts against the other end of the top post. The pressure cap has a groove extending axially along the valve stem assembly, and the second section has a slider that slides within the groove, so that the valve stem body can only move axially relative to the pressure cap.

9. The diaphragm-type fluid flow regulating device according to claim 8, characterized in that, It also includes a drive assembly for driving the valve stem assembly to move along its own axial direction, the drive assembly comprising: An inner sleeve is fitted onto the outside of the first section of the valve stem assembly, and the two are threadedly connected to form a first threaded mating part; An outer sleeve is fitted around the inner sleeve and drives the inner sleeve to move synchronously. The outer sleeve is fitted around the valve cover, and the outer sleeve and the valve cover are threadedly connected to form a second threaded mating part. The second threaded mating part has the same rotation direction as the first threaded mating part, and the pitch of the two has a difference. An operating part is fixedly connected to the outer sleeve so that the outer sleeve can be screwed on by the operating part.

10. The diaphragm-type fluid flow regulating device according to claim 9, characterized in that, The inner sleeve also includes an adjustment part that extends along the axial direction of the inner sleeve to the outside of the outer sleeve. The end of the adjustment part is provided with an adjustment interface for adjusting the threshold of the medium flow rate.

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