Looseness-proof and leakage-proof butterfly valve plate and valve rod connecting structure

Abstract

The utility model discloses an anti-loosening and anti-leakage butterfly valve plate and valve rod connecting structure, relates to the technical field of valve manufacturing, and solves the problems that a traditional connecting structure is easy to loosen, high in cost and not resistant to corrosion. According to the technical scheme, a split type special-shaped connecting piece is adopted, the straight portion of the split type special-shaped connecting piece is welded to a valve plate, and the arc portion is connected with a valve rod through a threaded bolt; the plug pin adopts fine threads and is provided with a conical guide head, and the end of the plug pin is locked and prevented from loosening through a nut with an elastic sealing rubber sleeve. The structure achieves the effects of reliable connection, vibration and looseness prevention, medium corrosion resistance and convenience in maintenance, and the service life and the reliability of the butterfly valve are remarkably improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to valve manufacturing technical field more specifically, it relates to a butterfly valve valve plate valve rod connecting structure of anti -loose leakproof. BACKGROUND

[0002] As a common fluid control equipment, butterfly valve realizes fluid control through the rotation of valve plate driven by valve rod, so the connection reliability of valve plate and valve rod is directly related to the service performance and working life of valve system. In the prior art, the connection between butterfly valve plate and valve rod usually adopts round pin connection or spline connection, some improved connection structures are connected by welding, and some connection structures are integrally cast with valve rod and then assembled with valve plate. However, the above connection methods have the following problems:

[0003] 1) The round pin structure is prone to pin loosening or even falling off due to vibration and impact during long-term use, which leads to the failure of valve plate and valve rod connection and affects the sealing performance of valve; 2) In terms of cost, although the spline connection is convenient to disassemble, it requires high machining precision and has high manufacturing cost, and there is still a risk of increased gap under harsh working conditions; the welded connection is difficult to disassemble during maintenance, and once damaged, it may cause the entire valve to be scrapped, resulting in high maintenance cost and being not conducive to resource conservation; the integrally cast structure cannot be adjusted, and the machining and assembly precision of valve plate is extremely harsh, and any deviation of valve plate may lead to assembly failure or assembly stress, resulting in loss cost; 3) In terms of service life, the existing connection structure has poor corrosion resistance, and the medium easily enters the inside of the connection part, causing corrosion of the parts and reducing the service life.

[0004] Therefore, how to research and design a butterfly valve plate valve rod connection structure with anti-loose and anti-leakage is a problem we need to solve at present. Utility model content

[0005] To solve the problems in the prior art, the utility model aims to provide a butterfly valve plate valve rod connection structure with anti-loose and anti-leakage, which separates the connection function from the valve rod by designing a split-type special-shaped connecting piece, significantly reduces the manufacturing difficulty and cost, and realizes convenient replacement and maintenance of the valve rod; the shear force is converted into screw surface pressure stress by the engagement of the threaded pin and the fine thread, which greatly enhances the vibration resistance and connection strength; the threaded pair loosening and corrosion medium intrusion are effectively prevented by combining the locking nut and the elastic sealing rubber sleeve, and finally the butterfly valve plate valve rod connection structure realizes high reliability, long service life, easy maintenance and excellent anti-loose and anti-leakage performance.

[0006] The above technical purpose of the utility model is realized by the following technical scheme:

[0007] Provided is a butterfly valve plate stem connection structure that prevents loosening and leakage, comprising a valve stem, a valve plate, and at least two special-shaped connecting pieces, wherein:

[0008] The flat portion is attached to the surface of the valve plate and is fixed by welding;

[0009] The center of the arc portion is provided with an inner hole to be sleeved on the outer circumference of the valve stem;

[0010] A first pin hole is formed in the side surface of the arc portion, and a second pin hole is formed in the corresponding position of the valve stem, the first pin hole and the second pin hole are coaxially aligned and connected and fixed by a pin.

[0011] Further, the pin is a threaded pin, the surface of which is provided with external threads, the inner walls of the first pin hole and the second pin hole are provided with internal threads that match the external threads, and the pin is connected by thread engagement.

[0012] Further, the threads of the threaded pin are fine threads, and the pitch of the threads is not greater than 0.8 mm.

[0013] Further, one end of the pin is provided with a tapered guide head, and the other end is provided with a hexagonal head for tightening by a tool, wherein the threads at the tapered guide head end are opposite in direction to the threads at the other end.

[0014] Further, the tapered guide head end of the pin is provided with a locking nut for fixing the pin.

[0015] Further, an elastic sealing rubber sleeve is sleeved on the locking nut, and when the locking nut is tightened, the elastic sealing rubber sleeve is compressed to seal the gap between the locking nut and the surface of the special-shaped connecting piece.

[0016] Further, the special-shaped connecting pieces are arranged at intervals along the axial direction of the valve stem and are uniformly distributed on the upper and lower sides of the valve plate.

[0017] Further, the special-shaped connecting pieces are made of stainless steel or alloy structural steel, and the surface thereof is chrome-plated, and the plating layer has a thickness of 0.02-0.05 mm.

[0018] Further, the welding between the flat portion and the valve plate is a continuous fillet weld, and the height of the weld is not less than half the thickness of the flat portion.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1. The utility model discloses a split type special-shaped connecting piece design separates the connecting function from the valve rod, significantly reduces the manufacturing difficulty and cost, and realizes convenient replacement and maintenance of the valve rod, adopts the engagement of threaded bolt and fine thread, converts shear force into screw surface pressure stress, greatly enhances the anti-vibration capacity and connecting strength, combines the locking nut and elastic sealing rubber sleeve, effectively prevents the loosening of threaded pair and the invasion of corrosive medium, and finally realizes the high reliability, long service life, easy maintenance and excellent anti-loose and anti-leakage performance of the butterfly valve plate valve rod connecting structure.

[0021] 2. The utility model discloses a split type special-shaped connecting piece design separates the connecting function from the valve rod, realizes the standardized manufacturing of valve rod and the independent processing of special-shaped connecting piece, significantly reduces the casting difficulty and production cost of complex components, and can replace the valve rod alone during maintenance, greatly improves the convenience and economy of maintenance.

[0022] 3. The utility model discloses a threaded bolt and locking nut and elastic sealing rubber sleeve cooperate, convert the shear force of traditional pin connection into screw surface pressure stress, and provide the double guarantee of mechanical anti-loose and elastic sealing, significantly enhance the anti-vibration loosening capacity and medium corrosion resistance of the connecting structure, thereby guaranteeing the long-term reliability of connection. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings described herein are used to provide further understanding of the embodiments of the utility model, constitute a part of this application, and do not constitute the limitation to the embodiments of the utility model. In the drawings:

[0024] Figure 1 It is the structure schematic diagram of the utility model;

[0025] Figure 2 It is the connecting structure section view of the utility model;

[0026] Figure 3 It is the bolt schematic diagram of the utility model;

[0027] 1, valve rod, 2, valve plate, 3, special-shaped connecting piece, 4, bolt, 5, locking nut, 6, elastic sealing rubber sleeve. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantage of the utility model more clear and obvious, the utility model is further explained in detail below by combining with the embodiment and drawing, and the illustrative embodiment of the utility model and its explanation are used to explain the utility model, and do not limit the utility model.

[0029] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly or indirectly attached to that other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to that other component.

[0030] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0031] 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 one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] Example: A butterfly valve plate and stem connection structure that prevents loosening and leakage, such as... Figure 1 As shown, the device includes a valve stem 1, a valve plate 2, and at least two irregularly shaped connectors 3. Each irregularly shaped connector 3 includes a straight portion and an arc portion. The straight portion fits against the surface of the valve plate 2 and is fixed by welding. The arc portion has an inner hole at its center to fit onto the outer circumference of the valve stem 1. A first pin hole is opened on the side of the arc portion, and a second pin hole is opened at the corresponding position on the valve stem 1. The first pin hole and the second pin hole are coaxially aligned and connected and fixed by a pin 4.

[0033] Traditional butterfly valves typically integrate the connecting structure with the valve stem 1 through casting, which leads to complex manufacturing processes, difficult maintenance, and high costs. Furthermore, the assembly process requires extremely high precision in machining and assembly. Therefore, this utility model adopts a split-type irregular connecting part 3 design, which effectively solves the above problems by separating the connecting function from the valve stem 1.

[0034] The irregularly shaped connector 3 is the core force-transmitting component of this design, integrally formed from a straight section and an arc section. The straight section has a wide flat surface for large-area contact with the side of the valve plate 2 for welding. The high degree of contact ensures uniform stress distribution during welding, direct force transmission, and significantly enhanced torque resistance. The arc section wraps around the valve stem 1, converting the torque transmitted from the valve plate 2 into a circumferential driving force on the valve stem 1 through the arc surface, resulting in more rational force distribution. A cross-sectional view of the mating components is shown below.Figure 2 As shown, the arc portion of the special-shaped connecting piece 3 is provided with an inner hole in the center, which is used for tightly wrapping the outer circumference of the valve stem 1, and the inner hole is in clearance fit with the valve stem 1; the bolt 4 transversely penetrates the first pin hole in the side surface of the special-shaped connecting piece 3 and the second pin hole on the valve stem 1 to form a threaded engagement connection; meanwhile, the locking nut 5 and the elastic sealing rubber sleeve 6 for the double protection mechanism of anti-loosening and anti-leakage are further included.

[0035] Since the ordinary material is easy to be damaged in the corrosion environment, the special-shaped connecting piece 3 of the utility model is made of stainless steel material and is treated by chrome plating, the chrome plating layer has a thickness of 0.03±0.01 mm and a hardness of HV800-1000, and the corrosion resistance and wear resistance are comprehensively improved.

[0036] In order to ensure that the strength of the welded connection is not lower than the strength of the base material, and the torque can be uniformly and smoothly transmitted, and the stress sharply increases at the end of the intermittent weld to cause fracture, the utility model also has requirements on the welding: the continuous fillet weld is used between the flat portion and the valve plate 2 to provide a complete and uninterrupted force flow path; the weld height is not less than half of the thickness of the flat portion to ensure that the carrying capacity of the weld itself is not lower than the carrying capacity of the flat portion of the special-shaped connecting piece 3 connected, and if the weld height is too small, it will become the weakest link in the entire force chain, and the stress will be concentrated in the small weld throat, and brittle fracture is prone to occur.

[0037] The special-shaped connecting piece 3 of the utility model is designed in a split type, the structure is optimized, special materials are used, and the welding is standardized, so that the standardization of manufacturing, the convenience of maintenance, the high reliability of connection and the long-term corrosion resistance are realized, and the pain points of the traditional integrated cast valve stem 1, such as high cost, difficult maintenance and easy damage, are comprehensively solved.

[0038] Since the single-point support is easy to cause the valve plate 2 to vibrate and deflect under the action of fluid, the utility model adopts the multi-point interval arrangement to improve the system stability and reliability. In general, the utility model adopts at least two special-shaped connecting pieces 3 to form stable support on the upper and lower sides of the valve plate 2, and a third support point can be added when necessary, the support point is increased to reduce the deflection of the valve stem 1, improve the inherent frequency of the system, and avoid the resonance phenomenon. The scientific arrangement scheme significantly improves the system stability and reduces the vibration.

[0039] Considering that the round pin connection is easy to loosen and fall off under the vibration condition, leading to connection failure, the utility model adopts the threaded bolt connection to improve the anti-vibration ability and connection strength through the threaded engagement.

[0040] The threaded pin 4 is made of alloy structural steel 40Cr, and the surface is processed with fine thread, the pitch of which is less than or equal to 0.8 mm, the shear stress mode of the pin connection is changed into the pressure stress distribution mode of the thread surface through the threaded connection, which can provide larger contact area and better self-locking performance, and effectively resist loosening caused by vibration.

[0041] Considering that the pin is usually difficult to assemble, the mating surface needs to be accurately aligned and is easily damaged, the utility model adopts the design of a conical guide head and a hexagonal head to solve the assembly alignment problem and improve the assembly efficiency.

[0042] As shown in Figure 3 The threaded pin of the utility model is designed with a 30° conical guide head at one end and a standardized hexagonal head at the other end, wherein the thread of the conical guide head is opposite to the thread direction of the main body of the threaded pin 4. During assembly, the conical guide head automatically guides the threaded pin 4 into the pin hole system composed of the special-shaped connecting piece 3 and the valve rod 1, and the thread is gradually screwed in by rotating the hexagonal head with a wrench, and the thread engagement length is controlled to be more than 1.5 times the diameter of the threaded pin 4. The conical guide head realizes the automatic centering function, the 30° conical angle takes into account the structural strength while ensuring the guiding function, and the hexagonal head provides a standard tool interface, which is convenient for rotating insertion with conventional tools. The unique end design improves the assembly efficiency, reduces the alignment difficulty, avoids part damage, and is particularly suitable for mass production conditions.

[0043] Considering that a single anti-loosening measure is prone to failure under long-term vibration, the utility model further locks with a lock nut 5 to ensure the connection reliability.

[0044] The utility model is provided with a lock nut 5 at the conical guide head end of the threaded pin 4, which cooperates with the thread at the conical guide head end, utilizes the synergistic effect of the axial tension generated by the nut and the thread friction, and forms a mutual restraint anti-loosening system. The anti-loosening mechanism ensures the connection reliability under harsh conditions, and vibration test shows that the pre-tightening force only decreases very low after multiple cycles, which is much lower than that of ordinary anti-loosening measures, the vibration resistance is significantly improved, and the maintenance period is prolonged.

[0045] Since the commonly used connection structure is prone to corrosion by the medium, which leads to difficult disassembly and shortened service life. The utility model adopts an elastic sealing rubber sleeve 6 to effectively prevent the corrosion medium from invading the connection part. The lock nut 5 is sleeved with an elastic sealing rubber sleeve 6 made of fluororubber material, which utilizes the elasticity and corrosion resistance of the fluororubber material to fill the micro gaps through compression deformation, and when the lock nut 5 is tightened, the elastic sealing rubber sleeve 6 is compressed to expand radially to seal the gap between the lock nut 5 and the surface of the special-shaped connecting piece 3.

[0046] The utility model discloses a plurality of protection mechanism realizes the comprehensive promotion of connection strength, assembly efficiency, anti-loose performance and sealing performance, makes the valve prolong service life under the harsh working condition, reduces maintenance cost.

[0047] Working principle: the utility model discloses the power connection of valve stem and valve plate through special-shaped connecting piece, first, the torque of valve stem drives special-shaped connecting piece through the engagement of bolt and special-shaped connecting piece, second, special-shaped connecting piece drives valve plate synchronous rotation through the continuous angle weld of straight part and valve plate, utilize fine thread bolt to enhance the connection strength and self -locking, combine with the locking nut of top and elastic sealing rubber sleeve, effectively prevent vibration and medium corrosion, finally realize reliable, efficient power transmission and long -term sealing anti -loose of valve stem to valve plate.

[0048] The above embodiment further specifically describes the purpose, technical scheme and beneficial effects of the utility model, and it should be understood that the above description is only a specific embodiment of the utility model, and is not used to limit the protection scope of the utility model, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A butterfly valve plate and stem connection structure that prevents loosening and leakage, characterized in that, It includes a valve stem (1), a valve plate (2), and at least two irregularly shaped connectors (3), wherein the irregularly shaped connectors (3) include a straight portion and an arc portion, wherein: The straight portion is attached to the surface of the valve plate (2) and fixed by welding; The center of the arc portion is provided with an inner hole so as to fit onto the outer circumference of the valve stem (1); A first pin hole is opened on the side of the arc portion, and a second pin hole is opened at the corresponding position of the valve stem (1). The first pin hole and the second pin hole are coaxially aligned and connected and fixed by a pin (4).

2. The anti-loosening and leak-proof butterfly valve plate and stem connection structure according to claim 1, characterized in that, The pin (4) is a threaded pin with an external thread on its surface. The inner walls of the first pin hole and the second pin hole have internal threads that match the external threads, and they are connected by thread engagement.

3. The anti-loosening and leak-proof butterfly valve plate and stem connection structure according to claim 2, characterized in that, The threaded pin has a fine thread with a pitch of no more than 0.8 mm.

4. The anti-loosening and anti-leakage butterfly valve plate and stem connection structure according to claim 1, characterized in that, One end of the pin (4) is provided with a tapered guide head, and the other end is provided with a hexagonal head for tightening by a tool, wherein the thread at the end of the tapered guide head is opposite to the thread at the other end.

5. The anti-loosening and anti-leakage butterfly valve plate and stem connection structure according to claim 4, characterized in that, The pin (4) has a locking nut (5) at its tapered guide end for fixing the pin (4).

6. The anti-loosening and anti-leakage butterfly valve plate and stem connection structure according to claim 5, characterized in that, An elastic sealing sleeve (6) is fitted on the locking nut (5). When the locking nut (5) is tightened, the elastic sealing sleeve (6) is compressed to seal the gap between the locking nut (5) and the surface of the irregular connector (3).

7. The anti-loosening and leak-proof butterfly valve plate and stem connection structure according to claim 1, characterized in that, The irregularly shaped connectors (3) are arranged at intervals along the axial direction of the valve stem (1) and are evenly distributed on the upper and lower sides of the valve plate (2).

8. The anti-loosening and leak-proof butterfly valve plate and stem connection structure according to claim 1, characterized in that, The irregular connector (3) is made of stainless steel or alloy structural steel, and its surface is chrome-plated with a plating thickness of 0.02-0.05mm.

9. The anti-loosening and leak-proof butterfly valve plate and stem connection structure according to claim 1, characterized in that, The weld between the straight portion and the valve plate (2) is a continuous fillet weld, and the height of the weld is not less than half the thickness of the straight portion.

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