A laser cladding repairing device for bidirectional sealing surface of metal hard sealing butterfly valve

Abstract

The application relates to the technical field of laser beam processing, in particular to a metal hard-seal butterfly valve bidirectional sealing surface laser cladding repair device. The device comprises a laser head, the laser head comprises a base head, the base head is fixedly connected to an execution end of a mechanical arm, a powder guide head is arranged at the bottom of the base head, the powder guide head is connected with a plurality of powder outlet ports of a powder feeder, a powder spraying head is arranged at the bottom of the powder guide head; a plurality of powder feeding channels are arranged between the powder guide head and the powder spraying head, the powder feeding end of the powder feeding channel is communicated with the powder feeder; a sleeve with a spiral slide is movably arranged on the outer wall of the powder spraying head, an axial movement adjustable distance adjusting assembly and a fixed stopper are arranged in the powder feeding channel to form an adjustable discharge gap, the sleeve can drive the distance adjusting assembly to move along the axial direction when the sleeve rotates, the discharge gap size is adjusted in real time according to the wear depth of different positions of the bidirectional sealing surface, and differential cladding of deep pit more filling and shallow pit less filling is realized.

Description

Technical Field

[0001] This invention relates to the field of laser beam processing technology, and more specifically, to a laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve. Background Technology

[0002] Metal hard-seal butterfly valves are key fluid control devices widely used in petroleum, chemical, power and other industrial fields. Their valve plate and valve seat sealing surfaces are made of metal materials, and excellent high temperature resistance, high pressure resistance and corrosion resistance are obtained by overlaying cobalt-based, nickel-based and other hard alloys.

[0003] Compared to ordinary butterfly valves or one-way sealing butterfly valves, two-way hard-seal butterfly valves refer to valves that can reliably seal against the valve seat by relying on the sealing surfaces on both sides of the valve plate, regardless of whether the medium pressure is in the forward or reverse direction, thus achieving a two-way zero-leakage sealing effect. Ordinary butterfly valves mostly adopt a centrally symmetrical structure, and the sealing pair is made of soft sealing material or simple metal hard seal, usually only considering the unidirectional medium flow direction.

[0004] During long-term service, the bidirectional sealing surfaces of bidirectional hard-seal butterfly valves are subjected to the combined effects of high temperature, high pressure and complex media environment. The metal sealing surfaces gradually fail due to the coupled effects of multiple damage mechanisms such as bidirectional media scouring, abrasive wear and chemical corrosion. When the damage depth exceeds a certain range and causes valve sealing failure, laser cladding technology is required to clad a high-performance alloy layer on the sealing surface to restore the original size and sealing performance.

[0005] For laser cladding repair of bidirectional hard-seal butterfly valves, the wear depth of the two sealing surfaces is often different due to the coupled effects of multiple damage mechanisms such as bidirectional media scouring, abrasive wear and corrosion during the service of the valve. Moreover, the amount of wear at different positions on the same sealing surface also varies significantly. This requires that the process parameters be dynamically adjusted according to the actual wear depth during the cladding process to achieve differentiated repair by filling more deep pits and less shallow pits, so as to ensure uniform cladding layer thickness.

[0006] To address this need, existing laser cladding technology has developed dynamic adjustment methods, which involve simultaneously adjusting the powder feed rate and laser power during the processing based on a preset program or real-time monitoring feedback, so that the powder supply is matched with the energy input, thereby obtaining the required cladding layer thickness at different wear locations.

[0007] However, existing laser cladding heads use a fixed powder feeding channel with fixed geometric parameters such as channel inclination angle and outlet width. When the powder amount is dynamically adjusted to compensate for wear at different depths, if the required powder amount increases significantly, the fixed-size channel is not convenient to be expanded accordingly, which can easily lead to powder accumulation in the channel and powder blockage failure.

[0008] Therefore, there is an urgent need for a laser cladding repair device for the bidirectional sealing surface of metal hard-seal butterfly valves to solve the above problems. Summary of the Invention

[0009] This invention provides a laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve. It utilizes a sleeve movably fitted onto the outer wall of a powder spraying head, driven by a rotating component to rotate the sleeve. A spiral slide on the inner wall of the sleeve drives an adjusting component to move axially within the powder feeding channel, thereby adjusting the discharge gap between the guide plate and the stop block. Simultaneously, a control system links the drive motor and robotic arm to achieve precise control of the powder feeding amount and synchronous reverse displacement of the laser head and guide plate, maintaining a relatively constant powder landing point and laser focus. This allows the device to dynamically adjust the powder feeding amount according to the wear depth at different locations on the bidirectional sealing surface, preventing powder accumulation and blockage in the feeding channel. This achieves differentiated and precise cladding, ensuring a uniform cladding layer thickness, thus solving the problems mentioned in the background art. Existing laser cladding heads use a fixed powder feeding channel with constant channel geometry. When the powder quantity is dynamically adjusted to compensate for wear at different depths on the bidirectional sealing surface, powder accumulation and powder blockage are likely to occur.

[0010] To achieve the above objectives, the metal hard-seal butterfly valve bidirectional sealing surface laser cladding repair device includes a frame, on which a laser head is mounted via a robotic arm. The laser head is equipped with a powder feeder. The laser head includes a base head, which is fixedly connected to the execution end of the robotic arm. A powder guide head is provided at the bottom of the base head, and the powder guide head is connected to multiple powder outlets of the powder feeder. A powder spraying head is provided at the bottom of the powder guide head. The base head, powder guide head and powder spray head are coaxially provided with a light-transmitting hole for the laser beam to be emitted. Multiple powder feeding channels are provided between the powder guide head and the powder spray head. The powder inlet end of the powder feeding channel is connected to the powder feeder. A sleeve is movably fitted on the outer wall of the powder spraying head. The sleeve and the powder spraying head are rotated together by a rotating assembly. A spiral slide is provided on the inner wall of the sleeve. A stop is fixedly installed in the powder feeding channel. An adjustment assembly is provided between the powder feeding channel and the spiral slide of the sleeve. When the sleeve rotates relative to the powder spraying head, the adjusting component is driven to move axially inside the powder feeding channel via the spiral slide to adjust the discharge gap between the adjusting component and the stop block.

[0011] In the above technical solution, because it is necessary to dynamically adjust the powder feeding amount to adapt to the wear of different depths of the bidirectional sealing surface, a sleeve is movably fitted on the outer wall of the powder spraying head. The rotational engagement between the sleeve and the powder spraying head is achieved by a rotating component. A spiral slide is provided on the inner wall of the sleeve, and a stop block and an adjusting component are fixed in the powder feeding channel. When the rotating component drives the sleeve to rotate, the spiral slide can convert the rotational motion into the axial movement of the adjusting component, thereby adjusting the discharge gap between the adjusting component and the stop block. The discharge gap can be flexibly adjusted. When more powder needs to be fed to areas with deeper wear on the bidirectional sealing surface, the gap can be increased to prevent powder from accumulating and clogging due to the fixed channel preventing expansion. When less powder needs to be fed to areas with shallower wear, the gap can be reduced to achieve differentiated repair by filling more powder to deep pits and less powder to shallow pits.

[0012] Based on this, the rotating assembly includes a gear ring fixedly connected to the top of the sleeve, a gear meshing with the inner wall of the gear ring, and a drive motor being driven by the gear through a shaft.

[0013] The outer wall of the powder spraying head is fixedly connected to a ring, which is movably engaged with the inner wall of the sleeve and forms a rotational support cooperation with the sleeve.

[0014] In another technical solution, the gap adjustment component includes a guide plate movably disposed inside the powder feeding channel, the guide plate being disposed opposite to the stop block, and an adjustable discharge gap being formed between the two.

[0015] Preferably, the adjusting assembly further includes a support plate, which has a Z-shaped structure and is movably connected to a groove on the outer wall of the powder spraying head. One end of the support plate is fixedly connected to the side wall of the guide plate, and the other end is fixedly connected to a slider, which is slidably connected to a spiral slide in the inner wall of the sleeve.

[0016] The stop block has a triangular block structure, with one side fixedly connected to the inner wall of the powder feeding channel and the other side set as a downward inclined surface to guide the powder guide plate in the powder feeding channel.

[0017] The guide plate is a downward-sloping inclined plate structure, and its tilt direction is opposite to that of the stop block, which is used to guide the powder towards the center point of the laser beam.

[0018] Furthermore, the slider is made of solid metal, while the guide plate and support plate are made of hollow, lightweight material to reduce the overall weight of the pitch adjustment assembly and decrease the frictional resistance between the slider and the spiral slide.

[0019] In this technical solution, the drive motor is electrically connected to the control system. The control system controls the rotation of the drive motor according to the correspondence between the rotation angle of the sleeve and the axial displacement of the guide plate, so as to adjust the discharge gap between the guide plate and the stop block.

[0020] In addition, the control system synchronously controls the robotic arm to drive the laser head to move in the opposite direction along the axis by the same distance according to the axial displacement of the guide plate, so as to keep the relative position of the powder landing point and the laser focus constant.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By movably sleeved with a spiral slide on the outer wall of the powder spraying head, and setting an axially movable adjusting component and a fixed stop block in the powder feeding channel to form an adjustable discharge gap, the adjusting component can be driven to move axially when the sleeve rotates, thereby adjusting the size of the discharge gap in real time according to the wear depth at different positions of the bidirectional sealing surface. When repairing deeper wear areas requires increasing the powder feeding rate, the discharge gap is correspondingly widened to expand the powder channel as needed, avoiding powder accumulation and blockage due to fixed channel size limitations. When repairing shallower wear areas requires reducing the powder feeding rate, the discharge gap is correspondingly narrowed to achieve differentiated cladding with more filling for deep pits and less filling for shallow pits, ensuring uniform cladding layer thickness and improving repair quality.

[0022] 2. The control system synchronously controls the robotic arm to drive the laser head to move in the opposite direction by the same distance according to the axial displacement of the pitch adjustment component, so that the relative position of the powder landing point and the laser focus remains constant. No matter how the discharge gap is adjusted, the laser head can compensate synchronously to avoid powder waste and cladding layer defects caused by powder misalignment, and ensure the stability and consistency of the cladding process. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the robotic arm connection structure of the present invention; Figure 3 This is a schematic diagram of the internal structure of the laser head of the present invention; Figure 4 This is a side view of the laser head structure of the present invention; Figure 5 This is a schematic diagram of the powder spraying channel structure of the present invention; Figure 6 This is a schematic diagram of the internal structure of the powder spraying head of the present invention; Figure 7 This is a schematic diagram of the ring support structure of the present invention; Figure 8 This is a schematic diagram of the rotating component structure of the present invention; Figure 9 This is a schematic diagram of the helical rotation of the pitch adjustment component of the present invention; Figure 10 This is a side view of the adjustable distance assembly structure of the present invention; Figure 11 This is a schematic diagram of the narrow-pitch cladding structure of the present invention; Figure 12 This is a schematic diagram of the wide-spacing cladding structure of the present invention.

[0024] The meanings of the labels in the diagram are as follows: 1. Laser head; 11. Base head; 12. Powder guide head; 13. Powder spray nozzle; 130. Ring; 14. Sleeve; 15. Rotating assembly; 150. Gear ring; 151. Gear; 16. Stop; 17. Adjustable distance assembly; 170. Guide plate; 171. Support plate; 172. Slider; 2. Powder feeder; 3. Robotic arm. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0026] Currently, in the laser cladding repair of bidirectional sealing surfaces, it is necessary to dynamically adjust the powder feeding amount to compensate for different wear depths. However, the existing laser cladding head has a fixed powder feeding channel structure and geometric parameters, which easily leads to powder accumulation and powder blockage. This invention provides a laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve. See [link to device]. Figures 1-4 As shown, the laser cladding head, as the execution terminal of the repair device, is fixedly installed on the execution end of the robotic arm 3 and is driven by the robotic arm 3 to move along a preset trajectory. The laser head 1 includes a base head 11, which is fixedly connected to the execution end of the robotic arm 3. A powder guide head 12 is provided at the bottom of the base head 11. The powder guide head 12 is connected to multiple powder outlets of the powder feeder 2. A powder spraying head 13 is provided at the bottom of the powder guide head 12. A light-transmitting hole for the laser beam to be emitted is coaxially provided at the center of the base head 11, the powder guide head 12, and the powder spraying head 13. The laser beam is focused through the light-transmitting hole and irradiates the surface of the workpiece to be repaired, forming a molten pool. A powder feeder 2 is connected to the periphery of the laser head 1. The powder feeder 2 stores alloy powder inside. Multiple powder feeding channels are provided between the powder guide head 12 and the powder spraying head 13. The powder feeding channels are connected to the powder feeding channels inside the laser head 1 through multiple powder outlets. The powder feeding channels are usually pipes with fixed geometric structures. Their inclination angle, outlet width and cross-sectional shape are determined when the laser head 1 is manufactured and cannot be adjusted during use. At work, such as Figure 5As shown, the powder feeder 2 delivers alloy powder to the end of the laser head 1 through the powder feeding channel. The powder is sprayed out along the fixed channel under the action of the carrier gas and falls into the molten pool formed by the laser beam. After being melted at high temperature, it forms a metallurgical bond with the workpiece substrate, thereby realizing cladding repair.

[0027] See Figure 6 As shown, the powder spraying head 13 serves as the powder spraying end of the laser head 1. A sleeve 14 is movably fitted onto its outer wall. The sleeve 14 has an annular hollow structure, and its inner diameter matches the outer diameter of the powder spraying head 13. This allows the sleeve 14 to rotate tightly against the outer wall of the powder spraying head 13 without affecting its normal operation. Figure 7 As shown, a ring 130 is fixedly connected to the outer wall of the powder spraying head 13. The ring 130 is an annular structure coaxially arranged with the powder spraying head 13. Its material is compatible with the material of the powder spraying head 13. It is fixed to the outer wall of the powder spraying head 13 by welding, bolt connection or integral molding. Its specific fixing position corresponds to the matching area of ​​the inner wall of the sleeve 14. Furthermore, an annular groove is provided on the inner wall of the sleeve 14 corresponding to the position of the ring 130. The inner diameter of the annular groove is adapted to the outer diameter of the ring 130, and the width of the annular groove is matched with the thickness of the ring 130, so that the ring 130 can be movably engaged in the annular groove and form a fit with the sleeve 14. This provides guidance and support for the rotation of the sleeve 14 relative to the powder spraying head 13, restricts the displacement of the sleeve 14 along the axial direction of the powder spraying head 13, and avoids vertical offset or shaking of the sleeve 14 during rotation, ensuring the coaxiality of the sleeve 14 during rotation. The rotating assembly 15 forms a rotational fit between the sleeve 14 and the powder spraying head 13, ensuring that the sleeve 14 rotates coaxially with respect to the powder spraying head 13.

[0028] For details, see Figure 8 As shown, the rotating assembly 15 serves as the power actuator for driving the sleeve 14 to rotate relative to the powder spraying head 13. It is mainly used to provide power for the rotation of the sleeve 14, ensuring that the sleeve 14 can rotate according to the instructions of the control system. The gear ring 150 is fixedly connected to the top end face of the sleeve 14 and is coaxially arranged with the sleeve 14. The gear ring 150 adopts a ring tooth structure, and its inner wall is evenly distributed with gear teeth. The specifications of the gear teeth are adapted to the specifications of the gear teeth of the gear 151. The gear 151 meshes with the inner wall of the gear ring 150. When the discharge gap of the powder feeding channel needs to be adjusted, the control system sends a control command to the drive motor. The drive motor starts and drives the shaft to rotate. The shaft synchronously drives the gear 151, which is fixedly connected to it, to rotate. Since the gear 151 meshes with the inner wall of the gear ring 150, the rotation of the gear 151 will drive the gear ring 150 to rotate synchronously. The gear ring 150 is fixedly connected to the sleeve 14, which in turn drives the sleeve 14 to rotate relative to the powder spraying head 13. During this process, the ring 130 on the outer wall of the powder spraying head 13 provides rotational support for the sleeve 14, restricts the axial displacement of the sleeve 14, and ensures that the sleeve 14 can rotate smoothly coaxially around the powder spraying head 13.

[0029] At this time, since the inner wall of the sleeve 14 is integrally formed with a spiral slide, and the spiral slide is evenly distributed along the circumferential direction of the inner wall of the sleeve 14 and extends in a continuous spiral shape; an adjustment component 17 is provided between the powder feeding channel and the spiral slide of the sleeve 14, and a stop 16 is fixedly provided inside the powder feeding channel. One end of the adjustment component 17 extends into the inside of the powder feeding channel and is positioned opposite to the stop 16. The other end passes through the side wall of the powder spraying head 13 and extends into the spiral slide of the inner wall of the sleeve 14, forming a sliding fit with the spiral slide, so that the adjustment component 17 can move along the axial direction of the powder spraying head 13 under the drive of the spiral slide.

[0030] For details, see Figure 9 and Figure 10 As shown, the pitch adjustment assembly 17 includes a guide plate 170 movably disposed inside the powder feeding channel. The guide plate 170 is disposed opposite to the block 16 fixedly disposed on the inner wall of the powder feeding channel, and a discharge gap is formed between the two to allow the powder to pass through. The guide plate 170 is a downwardly inclined plate structure, and its inclination direction is opposite to that of the block 16, which is used to guide the powder toward the center point of the laser beam. The baffle 16 is in the shape of a triangular block with three sides. One side is a fixed side, which is fixedly connected to the inner wall of the powder feeding channel, so that the baffle 16 is stably installed inside the powder feeding channel. The side of the baffle 16 near the top is set as a downward inclined surface, and the inclination angle of the inclined surface is towards the inner space of the powder feeding channel, which is used to guide the powder entering the powder feeding channel. When the powder is conveyed downward through the powder feeding channel, the powder first comes into contact with the inclined surface of the baffle 16. Under the guidance of the inclined surface, the direction of the powder movement changes from falling vertically to flowing downward along the inclined surface, thereby guiding the powder guide plate 170 to the side where the powder guide plate 170 is located, so that the powder can flow accurately to the area where the guide plate 170 is located.

[0031] In addition, the pitch adjustment assembly 17 also includes a support plate 171. The support plate 171 has a Z-shaped structure. Its middle part is movably connected to the groove opened on the outer wall of the powder spraying head 13, so that the support plate 171 can swing relative to the powder spraying head 13 around the connection point. One end of the support plate 171 is fixedly connected to the side wall of the guide plate 170, and the other end is fixedly connected to a slider 172. The slider 172 is slidably connected to the spiral slide in the inner wall of the sleeve 14. It should be noted that the middle part of the support plate 171 is movably connected to the slide groove opened on the outer wall of the powder spraying head 13 through a rotating shaft or a slot. The upper and lower walls of the slide groove form a limit on the support plate 171, so that it can only swing around the connection point within a certain angle, and cannot move radially or circumferentially along the powder spraying head 13. At the same time, the guide plate 170 is slidably disposed inside the powder feeding channel. The upper and lower walls of the powder feeding channel form a guide and limit on the guide plate 170, so that it can only move linearly along the axial direction of the powder spraying head 13. Therefore, when the sleeve 14 rotates and drives the slider 172 to move along the spiral slide, the movement of the slider 172 causes the support plate 171 to swing. However, since the support plate 171 and the guide plate 170 are both limited by their respective channels, the swing of the support plate 171 is converted into the axial linear motion of the guide plate 170, thereby achieving precise adjustment of the discharge gap. This transmission method is similar to the screw and nut mechanism, which converts rotational motion into linear motion, ensuring the stability and accuracy of the adjustment, and avoiding jamming or interference that may occur due to excessive freedom of movement.

[0032] See Figure 11 and Figure 12 As shown, when the sleeve 14 rotates relative to the powder spraying head 13, the spiral slide on the inner wall of the sleeve 14 rotates accordingly; since the slider 172 is slidably connected in the spiral slide, the rotational motion of the spiral slide drives the slider 172 to move along the spiral slide; the movement of the slider 172 causes the support plate 171 to swing around the connection point in its middle, and the swing of the support plate 171 in turn causes the guide plate 170, which is fixedly connected to it, to move along the axial direction of the powder feeding channel. The relative position between the guide plate 170 and the fixed stop 16 is changed by the axial movement of the guide plate 170, thereby adjusting the size of the discharge gap between them; when the sleeve 14 rotates and moves the guide plate 170 away from the stop 16, the discharge gap increases and the powder throughput increases; when the guide plate 170 moves closer to the stop 16, the discharge gap decreases and the powder throughput decreases.

[0033] In the above technical solution, it should be noted that the slider 172, as the part in the adjusting assembly 17 that directly contacts and slides relative to the spiral slide of the inner wall of the sleeve 14, is made of solid metal. Because solid metal has good wear resistance and structural strength, it can withstand the friction and compression generated when the slider 172 slides repeatedly in the spiral slide, ensuring that the slider 172 is not easily worn or deformed during long-term use, and ensuring the fitting accuracy and motion stability between the slider 172 and the spiral slide. The guide plate 170, as a component that is movable inside the powder feeding channel and directly participates in powder guidance, is made of hollow and lightweight material. By using hollow and lightweight material, the guide plate 170 can reduce its own weight while ensuring sufficient structural strength, and reduce the inertial force of the guide plate 170 when moving axially, making the movement of the guide plate 170 more sensitive and convenient. Furthermore, the support plate 171, as a transmission component connecting the guide plate 170 and the slider 172, is also made of hollow and lightweight material. Since the support plate 171 has a Z-shaped structure, one end of it is fixedly connected to the guide plate 170 and the other end is fixedly connected to the slider 172. During the movement of the adjusting assembly 17, it needs to move synchronously with the slider 172 and swing around the connection point. Using hollow and lightweight material can effectively reduce the weight of the support plate 171, reduce the inertia of the support plate 171 during swinging and movement, and make the movement of the support plate 171 more flexible and smooth.

[0034] It is important to note that in laser cladding repair, the powder feed rate is a key process parameter that determines the thickness of the cladding layer. Studies have shown that the height of the cladding layer is positively correlated with the powder feed rate, and the powder feed rate is the main factor driving the change in the height of the cladding layer. When the wear depth of the area to be repaired is large, the powder feed rate needs to be increased to obtain a thicker cladding layer and effectively fill the wear pits. When the wear depth is shallow, the powder feed rate should be reduced accordingly to avoid an excessively thick cladding layer that would increase the amount of subsequent machining. Therefore, in order to achieve the above-mentioned differentiated powder feeding, the existing technology usually obtains the three-dimensional morphology data of the surface to be repaired through offline measurement or online monitoring to determine the wear depth distribution at each location; the control system converts the wear depth data into the required powder feeding amount parameters for each area according to the preset mathematical model or empirical database; after obtaining the powder feeding amount requirements for each area, the control system sends control commands to the powder feeder 2 to drive the powder feeder 2 to adjust the powder feeding rate. The existing closed-loop control powder feeder 2 with real-time feedback function can respond quickly according to the set value, and make the powder feeding amount reach the target value and remain stable in a short time. At the same time, in order to ensure the cladding quality, the control system usually needs to adjust the laser power synchronously to match the powder supply with the energy input, so as to ensure that the powder is fully melted and the cladding layer is well formed. It should be noted that the control logic described above, which dynamically adjusts the powder feeding amount and laser power based on the wear depth, is a conventional technical method in the field of laser cladding repair. Existing technologies have developed a variety of closed-loop control systems that can achieve precise control of powder feeding amount and laser power by monitoring the molten pool temperature and size or by using real-time weighing feedback.

[0035] In this embodiment, based on the original control system logic, the drive motor is electrically connected to the control system, and the correspondence between the rotation angle of the sleeve 14 and the axial displacement of the guide plate 170 is pre-stored in the control system. This correspondence is determined by the lead parameter of the spiral slide, that is, for every unit angle that the sleeve 14 rotates, the displacement of the guide plate 170 along the axis is a fixed value. When it is necessary to adjust the discharge gap between the guide plate 170 and the stop block 16, the control system calculates the required displacement of the guide plate 170 based on the target discharge gap size, and then determines the required rotation angle of the sleeve 14 according to the above correspondence; the control system sends a control command to the drive motor, the drive motor starts and drives the sleeve 14 to rotate to the target angle, so that the guide plate 170 moves to the predetermined position, thereby adjusting the discharge gap size.

[0036] During the above adjustment process, the control system monitors the axial displacement of the guide plate 170 in real time, and synchronously controls the robotic arm 3 to drive the laser head 1 to move in the opposite direction along the axial direction by the same distance based on the displacement. Specifically, when the guide plate 170 moves downward, the powder spray angle changes, causing the powder landing point to decrease. The control system then controls the robotic arm 3 to drive the laser head 1 to move upward by the same distance. When the guide plate 170 moves upward, the control system controls the laser head 1 to move downward by the same distance. Through this synchronous reverse movement control, the relative position between the powder landing point and the laser focus remains constant, ensuring that the powder always falls into the laser molten pool.

[0037] Working principle: After the device is started, the robotic arm 3 moves the laser head 1 to the preset position of the bidirectional sealing surface of the metal hard-seal butterfly valve to be repaired. The laser system, powder feeder 2 and control system are started simultaneously. The laser beam is focused through the light-transmitting hole in the center of the laser head 1 and irradiates the area to be repaired on the bidirectional sealing surface, forming a high-temperature molten pool, which provides the necessary high-temperature environment for the cladding of alloy powder. At the same time, the powder feeder 2 starts to work, and under the action of the carrier gas, the alloy powder stored inside is transported to the powder feeding channel of the laser head 1 through multiple powder outlets. The powder is transported downward along the powder feeding channel. At this time, the control system determines the required amount of powder to be fed in each area based on the wear depth at different positions of the bidirectional sealing surface, and then sends a control command to the rotating component 15 to drive the sleeve 14 to rotate relative to the powder spraying head 13. When the sleeve 14 rotates, the spiral slide on its inner wall rotates synchronously. Through the cooperation of the spiral slide and the pitch adjustment component 17, the rotational motion is converted into the axial linear motion of the pitch adjustment component 17, which drives the pitch adjustment component 17 to move in the powder feeding channel. The movement of the pitch adjustment component 17 will change the relative distance between it and the fixed stop 16 in the powder feeding channel, and adjust the size of the discharge gap between the two. For areas with deeper wear, the discharge gap is widened to increase the powder throughput and achieve more filling; for areas with shallower wear, the discharge gap is narrowed to reduce the powder throughput and achieve less filling. This enables dynamic and differentiated control of the powder feeding rate, avoiding the problem of powder accumulation and blockage due to the inability to expand the channel. When the powder is conveyed to the discharge gap through the powder feeding channel, the inclined surface of the baffle 16 will first guide the powder and guide it smoothly to the guide plate 170 of the pitch adjustment component 17. Then, through the structural design of the guide plate 170 and the baffle 16 tilting in opposite directions, the powder is guided to the center point of the laser beam to ensure that the powder can fall accurately into the molten pool formed by the laser beam and ensure the effective interaction between the powder and the laser. During the axial movement of the pitch adjustment component 17, the control system monitors its displacement in real time and sends control commands to the robotic arm 3 in sync with the displacement to drive the laser head 1 to move in the opposite direction along the axis by the same distance. When the pitch adjustment component 17 moves downward, the laser head 1 moves upward in sync, and when the pitch adjustment component 17 moves upward, the laser head 1 moves downward in sync, so as to keep the relative position of the powder landing point and the laser focus constant, avoid the cladding shift caused by the change of powder spraying height, and ensure the forming accuracy and thickness uniformity of the cladding layer. Finally, after the alloy powder falling into the molten pool melts at high temperature, it forms a strong metallurgical bond with the substrate of the butterfly valve's bidirectional sealing surface, completing the cladding repair of this area. Then, the robotic arm 3 drives the laser head 1 to move slowly along the circular trajectory of the bidirectional sealing surface, repeating the above powder feeding adjustment, powder guiding and cladding process until the differential and precise cladding repair of the entire bidirectional sealing surface is completed, and finally the bidirectional zero-leakage sealing performance of the metal hard seal butterfly valve is restored.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve, comprising a frame, wherein a laser head (1) is mounted on the frame via a robotic arm (3), and the laser head (1) is equipped with a powder feeder (2), characterized in that: The laser head (1) includes a base head (11), which is fixedly connected to the execution end of the robotic arm (3). A powder guide head (12) is provided at the bottom of the base head (11), and the powder guide head (12) is connected to multiple powder outlets of the powder feeder (2). A powder spraying head (13) is provided at the bottom of the powder guide head (12). The base head (11), powder guide head (12) and powder spray head (13) are coaxially provided with a light-transmitting hole for the laser beam to be emitted. Multiple powder feeding channels are provided between the powder guide head (12) and the powder spray head (13). The powder inlet end of the powder feeding channel is connected to the powder feeder (2). The outer wall of the powder spraying head (13) is movably fitted with a sleeve (14), and the sleeve (14) and the powder spraying head (13) are rotated together by a rotating component (15). The inner wall of the sleeve (14) is provided with a spiral slide, and a stop block (16) is fixedly installed in the powder feeding channel. An adjustment component (17) is provided between the powder feeding channel and the spiral slide of the sleeve (14). When the sleeve (14) rotates relative to the powder spraying head (13), the pitch adjustment component (17) is driven to move axially inside the powder feeding channel via the spiral slide to adjust the discharge gap between the pitch adjustment component (17) and the stop block (16).

2. The laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve according to claim 1, characterized in that: The rotating assembly (15) includes a gear ring (150) fixedly connected to the top of the sleeve (14), and a gear (151) meshes with the inner wall of the gear ring (150). The gear (151) is connected to a drive motor via a shaft.

3. The laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve according to claim 1, characterized in that: The outer wall of the powder spraying head (13) is fixedly connected to a ring (130), which is movably engaged with the inner wall of the sleeve (14) and forms a rotational support cooperation with the sleeve (14).

4. The laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve according to claim 1, characterized in that: The adjustable gap assembly (17) includes a guide plate (170) movably disposed inside the powder feeding channel. The guide plate (170) is disposed opposite to the stop block (16), and an adjustable discharge gap is formed between the two.

5. The laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve according to claim 4, characterized in that: The adjustable distance assembly (17) also includes a support plate (171). The support plate (171) has a Z-shaped structure and is movably connected to the groove on the outer wall of the powder spraying head (13). One end of the support plate (171) is fixedly connected to the side wall of the guide plate (170), and the other end is fixedly connected to a slider (172). The slider (172) is slidably connected to the spiral slide in the inner wall of the sleeve (14).

6. The laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve according to claim 4, characterized in that: The stop block (16) has a triangular block structure. One side is fixedly connected to the inner wall of the powder feeding channel, and the other side is set as a downward inclined surface to guide the powder guide plate (170) in the powder feeding channel.

7. The laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve according to claim 4, characterized in that: The guide plate (170) is a downwardly inclined plate structure, and its inclination direction is opposite to that of the stop (16), which is used to guide the powder to the center point of the laser beam.

8. The laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve according to claim 5, characterized in that: The slider (172) is made of solid metal, and the guide plate (170) and support plate (171) are both made of hollow lightweight material to reduce the overall weight of the adjustment component (17) and reduce the frictional resistance between the slider (172) and the spiral slide.

9. The laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve according to claim 2, characterized in that: The drive motor is electrically connected to the control system. The control system controls the rotation of the drive motor according to the correspondence between the rotation angle of the sleeve (14) and the axial displacement of the guide plate (170), so as to adjust the discharge gap between the guide plate (170) and the stop block (16).

10. The laser cladding repair device for the bidirectional sealing surface of a metal hard-seal butterfly valve according to claim 9, characterized in that: The control system synchronously controls the robotic arm (3) to drive the laser head (1) to move in the opposite direction along the axis by the same distance according to the axial displacement of the guide plate (170), so as to keep the relative position of the powder landing point and the laser focus constant.

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