Low pressure plasma spraying apparatus and method of spraying

Abstract

The application discloses a low-pressure plasma spraying device and a spraying method thereof, which comprises a base plate and a processing chamber, the base plate is provided with the processing chamber, the processing chamber is divided into a pretreatment chamber and a low-pressure spraying chamber by a partition plate, the low-pressure spraying chamber is provided with a plasma spraying device through a mechanical arm, the pretreatment chamber and the low-pressure spraying chamber are provided with a clamping rotating mechanism through a moving assembly, which is used for moving the workpiece along the pretreatment chamber to the low-pressure spraying chamber, the base plate is symmetrically provided with a guide assembly, the low-pressure spraying chamber is provided with a collecting assembly below the plasma spraying device, and the collecting assembly is provided with a spraying mechanism at the bottom end. The spraying mechanism is matched with the collecting assembly, so that the particles in the spraying process can be conveniently collected, the large particles can be separately collected for subsequent reuse, the particles with appropriate diameters are matched with the spraying mechanism to be sprayed out, the workpiece surface can be decontaminated, the cleanliness of the surface is ensured, the subsequent spraying processing is not affected, and the spraying quality is ensured.

Description

Technical Field

[0001] This invention belongs to the field of low-pressure plasma spraying technology, specifically, it relates to a low-pressure plasma spraying equipment and its spraying method. Background Technology

[0002] Plasma spraying, a key surface treatment process, works by using electrical energy to convert a mixture of gases such as argon, hydrogen, or helium into high-temperature plasma, forming a plasma jet within the anode. This high-temperature, high-speed plasma gas stream allows for the precise spraying of coating materials such as metals, metal oxides, and metal carbides onto the workpiece surface, resulting in a high-performance coating. Under low-pressure conditions, the plasma expands rapidly after being ejected from the spray gun. As the ambient pressure decreases, the plasma density gradually decreases, while the plasma free path increases accordingly. In many industrial fields, such as pipe manufacturing, plasma spraying technology has been widely applied due to its unique advantages. By forming a high-quality coating on the surface of pipes, it can significantly improve their wear resistance, corrosion resistance, and other properties.

[0003] In low-pressure plasma spraying processes, the workpiece surface typically requires pretreatment to remove impurities such as dust and oxide layers before spraying. However, in some actual processing scenarios, some workpieces can be sprayed immediately after pretreatment. In these cases, the pretreatment process does not adversely affect the spraying process and ensures its smooth execution.

[0004] However, for some workpieces, due to production needs (such as batch processing) and other factors, temporary storage is necessary after pretreatment. Although the storage time is relatively short, the surface of the pretreated workpiece is rough and charged, making it highly susceptible to adsorbing dust, fibers, and other particles from the air. Furthermore, in humid environments, the metal surface easily reacts with oxygen and moisture, forming a thin rust layer. The adsorbed particles and the resulting rust layer significantly impact the coating quality during subsequent spraying, leading to reduced adhesion between the coating and the workpiece surface, poor coating uniformity, and ultimately affecting the overall performance and service life of pipe fittings and other workpieces. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a low-pressure plasma spraying device.

[0006] To achieve the aforementioned objectives, the present invention employs the following technical solution: a base plate and a processing chamber. The processing chamber is located on the base plate and is divided into a pretreatment chamber and a low-pressure spraying chamber by a partition. A plasma spraying device is located in the low-pressure spraying chamber via a robotic arm. A clamping and rotating mechanism is located in the pretreatment chamber and the low-pressure spraying chamber via a moving assembly. The clamping and rotating mechanism is matched with the workpiece and is used to move the workpiece along the pretreatment chamber to the low-pressure spraying chamber. Guide components are symmetrically arranged on the base plate, with two sets of guide components located in the pretreatment chamber and the low-pressure spraying chamber, respectively. A collection assembly is located below the plasma spraying device in the low-pressure spraying chamber. A spraying mechanism is located at the bottom of the collection assembly and extends into the pretreatment chamber.

[0007] Preferably, the partition has a plug-in plate in the middle, and the top and bottom of the plug-in plate are provided with a locking plate. The partition has a locking groove that engages with the locking plate, and the plug-in plate has a wiping sleeve in the middle. The inner diameter of the wiping sleeve gradually decreases along the direction of workpiece movement.

[0008] In this invention, the wiping sleeve allows for easy wiping of the processed workpiece surface, ensuring surface cleanliness and guaranteeing the quality of subsequent spraying. It also facilitates the disassembly of the connector plate, making it convenient to clean or replace the wiping sleeve.

[0009] Preferably, the moving component includes a linear moving device symmetrically arranged in the pretreatment chamber, a guide rail slider is provided under the linear moving device, and a moving plate is fixedly provided at the bottom end of the guide rail slider. The structure of the moving component in the low-pressure spraying chamber is the same as that of the moving component in the pretreatment chamber.

[0010] Preferably, the length of the low-pressure spraying chamber along the workpiece movement direction is greater than the length of the pretreatment chamber.

[0011] Preferably, the clamping and rotating mechanism includes a top plate rotatably mounted on the side wall of the movable plate in the pretreatment chamber, an anti-slip pad being provided at the end of the top plate away from the movable plate, a motor being provided on the side wall of the movable plate in the low-pressure spraying chamber, a plug-in post being provided at the output end of the motor, and a positioning pad being provided outside the plug-in post.

[0012] In this invention, the movable component, in conjunction with the clamping and rotating mechanism, can easily clamp and fix the workpiece, and then move it as a whole. During the movement, it can easily rotate axially, allowing for surface pretreatment and spraying to ensure a complete finish.

[0013] Preferably, the guide assembly includes support columns symmetrically arranged on the base plate, a guide plate fixedly mounted on the support columns, and ball bearings equidistantly rotating on the inner arc surface of the guide plate, the ball bearings matching the workpiece.

[0014] Preferably, a connecting plate is fixedly provided at one end of the guide plate in the pretreatment chamber. The connecting plate is located at the end near the partition, and a grinding strip is provided on the inner arc surface of the connecting plate.

[0015] In this invention, the provided guide component can guide and limit the movement of the workpiece during its movement and rotation, ensuring stable movement and preventing deviation. At the same time, the pretreatment chamber is also equipped with a grinding belt to facilitate grinding of the workpiece's peripheral surfaces, removing dust and rust, and ensuring the cleanliness of the workpiece.

[0016] Preferably, the collection assembly includes a collection tank disposed in the pretreatment chamber, a collection box disposed below the collection tank, and a collection hopper disposed in the low-pressure spraying chamber. The bottom end of the collection hopper is provided with a collection pipe, a filter screen is inclinedly disposed inside the collection pipe, and a discharge pipe is inclinedly disposed on the side wall of the collection pipe, with the discharge pipe located above the lower end of the filter screen.

[0017] Preferably, the ejection mechanism includes a connecting pipe disposed at the bottom of the collecting pipe, an air vent disposed at an angle on the side wall of the connecting pipe, an acceleration pipe disposed in the vertical section of the connecting pipe, and an ejection nozzle disposed at the top end of the acceleration pipe penetrating the bottom plate and extending into the interior.

[0018] In this invention, the collection component and the spraying mechanism can be used to collect the particles that fall off after spraying. Then, the spraying mechanism can be used to spray particles of appropriate size along with the airflow to re-process the workpiece surface and ensure the surface is clean.

[0019] According to another aspect of the present invention, a spraying method using a low-pressure plasma spraying apparatus is also provided, comprising the following steps:

[0020] Step 1: Place the workpiece on the guide tray in the pretreatment chamber. The linear moving device in the low-pressure spraying chamber moves the moving block towards one end of the partition, bringing the insertion post under the moving plate closer to the workpiece. The insertion post passes through the wiping sleeve and the positioning pad, and is inserted into the workpiece. The other end, in conjunction with the top plate and anti-slip pad, clamps and fixes the workpiece.

[0021] Step 2: The two sets of linear moving devices work synchronously, moving the moving plate under the guide rail slider. This can move the workpiece towards the low-pressure spraying chamber. At the same time, the motor rotates in the forward direction, causing the plug-in column, workpiece, and top plate to rotate axially. During the movement, the guide plate cooperates with the ball bearings to assist in guiding and lifting. Meanwhile, the grinding belt on the connecting plate treats the circumferential side of the workpiece. Nitrogen gas is introduced through the air pipe, carrying the sprayed particles along with it. Then, it is accelerated through the acceleration pipe and sprayed out through the nozzle to remove impurities from the workpiece surface.

[0022] Step 3: After the impurity removal is completed, the linear moving device continues to work, carrying the workpiece. The surface of the workpiece can be wiped by the wiping sleeve. Then it moves to the low-pressure spraying chamber. The robotic arm moves the plasma spraying device to spray the workpiece. The particles that fall off during the spraying process are collected by the collection bucket. The filter screen in the collection pipe filters out particles of appropriate size and they fall down for subsequent spraying and impurity removal. Larger particles are discharged through the discharge pipe.

[0023] Step 4: After the spraying and cooling are completed, the linear moving device in the pretreatment chamber moves and resets, the top plate moves away from the workpiece, the workpiece can be pulled and removed from the plug-in column, and the processing is completed. When it is necessary to clean or replace the wiping sleeve, the plug-in plate can be pulled, the clamping plate slides in the clamping slot, and the plug-in plate can be removed to facilitate the cleaning or replacement of the wiping sleeve.

[0024] Compared with the prior art, the advantages of the present invention include:

[0025] (1) The present invention provides a low-pressure plasma spraying equipment and spraying method. With the collection component and the spraying mechanism, the particles in the spraying process can be collected in a convenient way. The separate collection of large particles is convenient for subsequent reuse. The appropriate particle size is sprayed out with the spraying mechanism to remove impurities from the workpiece surface, ensure the cleanliness of the surface, not affect the subsequent spraying process, and ensure the quality of the spraying.

[0026] (2) The low-pressure plasma spraying equipment and spraying method provided by the present invention, through the guide component and the grinding belt, can be conveniently guided and limited during the workpiece conveying process to avoid deviation, and can also clean the surface dust and rust.

[0027] (3) The low-pressure plasma spraying equipment and spraying method provided by the present invention can conveniently clamp and transport the workpiece by means of a movable component and a rotating clamping mechanism. By clamping both ends, the pretreatment and spraying of the workpiece's peripheral side is not affected. In addition, the workpiece can be rotated axially during the transport process, and the peripheral side can be thoroughly cleaned and processed to avoid dead corners.

[0028] (4) The present invention provides a low-pressure plasma spraying equipment and spraying method, which can deeply clean the surface of the workpiece through the wiping sleeve provided on the plug plate. The moving component and the clamping and rotating mechanism work together to achieve efficient and comprehensive spraying, and also facilitate the disassembly of the plug plate for cleaning or replacement. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is an overall schematic diagram of a low-pressure plasma spraying device according to the present invention;

[0031] Figure 2 This is a partial schematic diagram of a low-pressure plasma spraying device according to the present invention, showing the workpiece located in the pretreatment chamber;

[0032] Figure 3 This is a partial schematic diagram of a low-pressure plasma spraying device according to the present invention, showing the workpiece located in the low-pressure spraying chamber.

[0033] Figure 4 This is a partial structural diagram of the pretreatment chamber in a low-pressure plasma spraying device according to the present invention;

[0034] Figure 5 This is a partial structural diagram of the low-pressure spraying chamber in a low-pressure plasma spraying device according to the present invention;

[0035] Figure 6 This is an overall schematic diagram of the robotic arm and plasma spraying device in a low-pressure plasma spraying equipment according to the present invention.

[0036] Figure 7 This is an overall schematic diagram of the partition in a low-pressure plasma spraying device according to the present invention;

[0037] Figure 8 This is an overall schematic diagram of the collection component and the spraying mechanism in a low-pressure plasma spraying device according to the present invention;

[0038] Figure 9 This is a partial structural diagram of the collection pipe and discharge pipe in a low-pressure plasma spraying device according to the present invention.

[0039] Figure label:

[0040] 11. Base plate; 12. Machining chamber; 13. Workpiece; 14. Robotic arm; 15. Plasma spraying device; 21. Partition; 22. Pretreatment chamber; 23. Low-pressure spraying chamber; 31. Connecting plate; 32. Slot; 33. Card plate; 34. Wiping sleeve; 41. Linear movement device; 42. Guide rail slider; 43. Moving plate; 51. Top plate; 52. Anti-slip pad; 53. Motor; 54. Connecting post; 55. Positioning pad; 61. Support column; 62. Guide plate; 63. Ball bearing; 64. Grinding belt; 65. Connecting plate; 71. Collection pipe; 72. Collection hopper; 73. Vent pipe; 74. Connecting pipe; 75. Acceleration pipe; 76. Nozzle; 77. Collection tank; 78. Collection box; 81. Filter screen; 82. Discharge pipe. Detailed Implementation

[0041] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solution, its implementation process, and principles will be further explained below with reference to the accompanying drawings and specific implementation examples in the embodiments of this application.

[0042] It should be noted that the embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, the present invention covers any substitutions, modifications, equivalent methods and solutions made on the spirit, principles and scope of the present invention as defined by the claims. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] In the description of this application, the terms "first," "second," "third," and similar words do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a" or "one," and similar words, do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including," and similar words, mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including," and their equivalents, but do not exclude other elements or objects. The terms "connected" or "linked," and similar words, are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0044] In the description of this application, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this application and for simplification, 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 application. Furthermore, when using positional terms such as "both sides," "outer side," and "upper and lower," it should be understood that they are used only for ease of understanding and description, taking into account that the structure may be oriented to other positions.

[0045] In the description of this application, unless otherwise expressly specified and limited, the technical or scientific terms used shall have the ordinary meaning understood by a person with ordinary skills in the art to which this application pertains. Terms such as “installation,” “connection,” and “joining” shall be interpreted broadly, for example, as fixed connection, detachable connection, mating connection, or integral connection. For a person skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0046] The present invention aims to introduce and explain the structural composition of a low-pressure plasma spraying device and its spraying method, as well as the cooperation relationship between the various components. Unless otherwise specified, the dimensions, materials, and manufacturing processes of the various components in the low-pressure plasma spraying device and its spraying method in the present invention can be selected according to specific circumstances, and no special limitations or explanations are made here.

[0047] Furthermore, to provide the public with a better understanding of the present invention, certain specific details are described in detail in the following description of the invention. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0048] Please see Figures 1-9A low-pressure plasma spraying device includes a base plate 11 and a processing chamber 12. The processing chamber 12 is partially shown in the figure; the chamber door is not shown. The door allows for easy opening and closing of the processing chamber 12, facilitating the placement, processing, and subsequent removal of workpieces 13. The processing chamber 12 is mounted on the base plate 11 and is divided into a pretreatment chamber 22 and a low-pressure spraying chamber 23 by a partition 21. The low-pressure spraying chamber 23 is equipped with a vacuum pump (a combination of a Roots pump and a molecular pump) and an inert gas introduction device, allowing for the introduction of inert gas for protection after creating a low-pressure environment through vacuuming. The high purity and high bonding strength of the coating are relatively mature technologies and will not be elaborated upon here. The low-pressure spraying chamber 23 is controlled by a robotic arm 14 (a multi-axis robotic arm, four-axis or six-axis linkage system), and a plasma spraying device 15, which mainly consists of a spray gun and also includes a powder feeder and powder storage tank. +Carrier gas channel, for powder, vacuum deoxygenation + drying, prevents oxidation and inclusion, etc., facilitates plasma spraying of workpiece 13 in a low-pressure environment. It is a relatively mature technology and will not be elaborated here. The pretreatment chamber 22 and the low-pressure spraying chamber 23 are equipped with clamping and rotating mechanisms through moving components. The clamping and rotating mechanisms are matched with workpiece 13 to facilitate clamping and moving of workpiece 13. At the same time, it is also convenient to rotate axially to facilitate the treatment of the peripheral side of workpiece 13. Then, it is convenient to carry workpiece 13 to move along the pretreatment chamber 22 to the low-pressure spraying chamber 23. The base plate 11 is symmetrically equipped with guide components. Two sets of guide components are located in the pretreatment chamber 22 and the low-pressure spraying chamber 23 respectively. The low-pressure spraying chamber 23 is equipped with a collection component under the plasma spraying device 15. The bottom end of the collection component is equipped with a spraying mechanism that extends into the interior of the pretreatment chamber 22.

[0049] Please see Figures 1-9 To facilitate wiping the surface of the processed workpiece 13 without affecting subsequent spraying, and to facilitate cleaning or replacement of the wiping sleeve 34, a plug-in plate 31 is provided in the middle of the partition 21. The top and bottom of the plug-in plate 31 are provided with a retaining plate 33. The partition 21 has a retaining groove 32 that engages with the retaining plate 33. To ensure the stability of the plug-in, an elastic pad, such as rubber, can be glued into the retaining groove 32 to prevent slippage after plugging. The plug-in plate 31 also has a wiping sleeve 34 in the middle. The inner diameter of the wiping sleeve 34 gradually decreases along the moving direction of the workpiece 13. The shape of the wiping sleeve 34 is a hollow frustum, which is convenient to adapt to tubular workpieces 13 of different diameters and facilitates wiping of the surface.

[0050] Please see Figures 1-9To facilitate the movement of workpiece 13 for pretreatment and spraying operations, and to ensure comprehensive processing and spraying by allowing workpiece 13 to rotate axially during movement, the moving assembly includes a linear moving device 41 symmetrically arranged within the pretreatment chamber 22. A guide rail slider 42 is located below the linear moving device 41. The linear moving device 41 can be driven by a linear motor 53 to achieve the reciprocating movement of the guide rail slider 42. Alternatively, a reciprocating screw or other mature technology can be used for reciprocating movement, which will not be elaborated upon here. A moving plate 43 is fixedly installed at the bottom of the guide rail slider 42. The structure of the moving assembly within the low-pressure spraying chamber 23 is the same as that within the pretreatment chamber 22. The length of the low-pressure spraying chamber 23 along the direction of workpiece 13 movement is greater than... The length of the pretreatment chamber 22 facilitates the movement and spraying of the subsequent workpiece 13, as well as the removal of the workpiece 13 after completion. The clamping and rotating mechanism includes a top plate 51 rotatably mounted on the side wall of the moving plate 43 of the pretreatment chamber 22, which can be rotatably connected by a rotating shaft. The end of the top plate 51 away from the moving plate 43 is attached with an anti-slip pad 52 to avoid hard contact with the end of the workpiece 13, making it easy to clamp one end of the workpiece 13. With the help of the insertion post 54, the workpiece 13 can be clamped and fixed. A motor 53 is provided on the side wall of the moving plate 43 of the low-pressure spraying chamber 23. The output end of the motor 53 is fixedly connected to the insertion post 54 through a coupling. The insertion post 54 is provided with a positioning pad 55 on the outside. The positioning pad 55 and the insertion post 54 are frustum-shaped, which facilitates the insertion of workpieces 13 with different inner diameters.

[0051] Please see Figures 1-9To guide the workpiece 13 during movement and facilitate surface treatment to remove dust and rust, ensuring cleanliness and preventing interference with subsequent painting, a guide assembly is symmetrically arranged on the base plate 11. The guide assembly includes support columns 61 symmetrically arranged on the base plate 11, with guide plates 62 welded to the support columns 61. An arc-shaped groove is formed at the top of the guide plate 62, and ball bearings 63 are equidistantly mounted on the inner arc surface of the guide plate 62. The ball bearings 63 match the workpiece 13, facilitating guidance and limiting during the workpiece 13's movement while reducing contact friction. One end of the guide plate 62 is fixed within the pretreatment chamber 22. A connecting plate 65 is provided, located at one end near the partition 21. The inner arc surface of the connecting plate 65 has a grinding belt 64 for facilitating the grinding of the workpiece 13 surface, removing floating dust and rust. The collection assembly includes a collection trough 77 located in the pretreatment chamber 22, with a collection box 78 below it. The collection box 78 can be equipped with a fan or similar device (similar to a vacuum cleaner) for convenient collection of debris. The collection assembly also includes a collection hopper 72 located in the low-pressure spray chamber 23 for collecting particles falling during spraying. A collection pipe 71 is located at the bottom of the collection hopper 72, with a filter screen 8 inclined inside the collection pipe 71. 1. A discharge pipe 82 is inclined on the side wall of the collection pipe 71. The discharge pipe 82 is located above the lower end of the filter screen 81. Large-diameter particles can be intercepted and filtered by the filter screen 81 and discharged through the discharge pipe 82 for collection, facilitating subsequent recycling. Particles of suitable diameter fall into the connecting pipe 74 through the collection pipe 71. The spraying mechanism includes a connecting pipe 74 located at the bottom of the collection pipe 71. A vent pipe 73 is inclined on the side wall of the connecting pipe 74. The vent pipe 73 is connected to the side wall of the main pipe at an acute angle of 30°–60°. The vent pipe 73 is connected to a compressed nitrogen delivery device, such as a compressor pump (not shown in the figure), which is a relatively mature technology. To facilitate the transport of nitrogen gas and particles, the branched airflow cuts obliquely into the main flow to form a spiral flow, reducing frictional resistance and increasing the flow velocity at the end. The vertical section of the connecting pipe 74 is equipped with an acceleration pipe 75, which can be a Venturi tube. The pressure difference is generated through the contraction-expansion structure of the pipe section. The Bernoulli effect is used to accelerate the airflow and particles when the flow velocity increases and the pressure decreases. The top of the acceleration pipe 75 passes through the bottom plate 11 and extends into the interior to provide a nozzle 76, which facilitates the spraying of nitrogen gas and particles together to knock off impurities from the surface of the workpiece 13. It can also blow off impurities for subsequent collection, ensuring the cleanliness of the surface of the workpiece 13.

[0052] According to another aspect of the present invention, a spraying method for a low-pressure plasma spraying apparatus is also provided, comprising the following steps:

[0053] Step 1: Place the workpiece 13 on the guide plate 62 of the pretreatment chamber 22. The linear moving device 41 in the low-pressure spraying chamber 23 moves the moving block towards one end of the partition 21, and brings the insertion post 54 under the moving plate 43 closer to the workpiece 13. It passes through the wiping sleeve 34 and cooperates with the positioning pad 55 to insert the insertion post 54 into the workpiece 13. The other end cooperates with the top plate 51 and the anti-slip pad 52 to clamp and fix the workpiece 13.

[0054] Step 2: The two sets of linear moving devices 41 work synchronously, moving the moving plate 43 under the guide rail slider 42, which can move the workpiece 13 towards the low-pressure spraying chamber 23. At the same time, the motor 53 rotates in the forward direction, causing the plug-in post 54, workpiece 13 and top plate 51 to rotate axially. During the movement, the guide plate 62 cooperates with the ball bearing 63 to assist in guiding and lifting. At the same time, the grinding belt 64 on the connecting plate 65 treats the circumferential side of the workpiece 13. Nitrogen gas is introduced through the air pipe 73, which moves along with the sprayed particles. Then it is accelerated through the acceleration pipe 75 and sprayed out through the nozzle 76 to remove impurities from the surface of the workpiece 13.

[0055] Step 3: After the impurity removal is completed, the linear moving device 41 continues to work, carrying the workpiece 13 to continue moving. The surface of the workpiece 13 can be wiped by the wiping sleeve 34. Then it moves into the low-pressure spraying chamber 23. The robotic arm 14 works to carry the plasma spraying device 15 to perform spraying operation on the workpiece 13. The particles that fall off during the spraying process are collected by the collection hopper 72. The filter screen 81 in the collection pipe 71 filters out particles of appropriate size and drops them down for subsequent spraying to remove impurities. Larger particles are discharged through the discharge pipe 82.

[0056] Step 4: After the spraying and cooling are completed, the linear moving device 41 in the pretreatment chamber 22 moves and resets, the top plate 51 moves away from the workpiece 13, the workpiece 13 can be pulled and removed from the plug-in post 54 to complete the processing. When it is necessary to clean or replace the wiping sleeve 34, the plug-in plate 31 can be pulled, the clamping plate 33 slides in the clamping groove 32, and the plug-in plate 31 can be removed to facilitate the cleaning or replacement of the wiping sleeve 34.

[0057] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A low-pressure plasma spraying device, comprising a base plate (11) and a processing chamber (12), wherein the processing chamber (12) is provided on the base plate (11), and the processing chamber (12) is divided into a pretreatment chamber (22) and a low-pressure spraying chamber (23) by a partition (21), and a plasma spraying device (15) is provided in the low-pressure spraying chamber (23) by a robotic arm (14), characterized in that: The pretreatment chamber (22) and the low-pressure spraying chamber (23) are equipped with a clamping and rotating mechanism through a moving component. The clamping and rotating mechanism is matched with the workpiece (13) and is used to move the workpiece (13) along the pretreatment chamber (22) to the low-pressure spraying chamber (23). The base plate (11) is symmetrically equipped with guide components. The two sets of guide components are located in the pretreatment chamber (22) and the low-pressure spraying chamber (23) respectively. The low-pressure spraying chamber (23) is located below the plasma spraying device (15) and is equipped with a collection component. The bottom end of the collection component is equipped with a spraying mechanism. The spraying mechanism extends into the interior of the pretreatment chamber (22). The partition (21) is provided with a plug-in plate (31) in the middle, and the plug-in plate (31) is provided with a locking plate (33) at the top and bottom. The partition (21) is provided with a locking groove (32) that engages with the locking plate (33). The plug-in plate (31) is provided with a wiping sleeve (34) in the middle. The inner diameter of the wiping sleeve (34) gradually decreases along the moving direction of the workpiece (13). The clamping and rotating mechanism includes a top plate (51) rotatably mounted on the side wall of the movable plate (43) in the pretreatment chamber (22). The top plate (51) is provided with an anti-slip pad (52) at one end away from the movable plate (43). A motor (53) is provided on the side wall of the movable plate (43) in the low-pressure spraying chamber (23). A plug-in post (54) is provided at the output end of the motor (53). A positioning pad (55) is provided outside the plug-in post (54). The collection assembly includes a collection trough (77) disposed in the pretreatment chamber (22), a collection box (78) disposed below the collection trough (77), and the collection assembly also includes a collection hopper (72) disposed in the low-pressure spray chamber (23), a collection pipe (71) disposed at the bottom of the collection hopper (72), a filter screen (81) disposed inclined inside the collection pipe (71), and a discharge pipe (82) disposed inclined on the side wall of the collection pipe (71), the discharge pipe (82) being located above the lower end of the filter screen (81); The ejection mechanism includes a connecting pipe (74) at the bottom of the collecting pipe (71), an air vent (73) on the side wall of the connecting pipe (74) at an incline, and an acceleration pipe (75) in the vertical section of the connecting pipe (74). The top of the acceleration pipe (75) passes through the bottom plate (11) and extends to the inside to provide a nozzle (76).

2. The low-pressure plasma spraying equipment according to claim 1, characterized in that: The moving component includes a linear moving device (41) symmetrically arranged in the pretreatment chamber (22), a guide rail slider (42) is provided under the linear moving device (41), and a moving plate (43) is fixedly provided at the bottom end of the guide rail slider (42). The structure of the moving component in the low-pressure spraying chamber (23) is the same as that of the moving component in the pretreatment chamber (22).

3. The low-pressure plasma spraying equipment according to claim 2, characterized in that: The length of the low-pressure spraying chamber (23) along the direction of movement of the workpiece (13) is greater than the length of the pretreatment chamber (22).

4. The low-pressure plasma spraying equipment according to claim 3, characterized in that: The guide assembly includes support columns (61) symmetrically arranged on the base plate (11), a guide plate (62) fixedly provided on the support column (61), and ball bearings (63) rotatably provided on the inner arc surface of the guide plate (62) at equal intervals, the ball bearings (63) matching the workpiece (13).

5. The low-pressure plasma spraying equipment according to claim 4, characterized in that: A connecting plate (65) is fixedly provided at one end of the guide plate (62) in the pretreatment chamber (22). The connecting plate (65) is located at one end near the partition (21), and a grinding belt (64) is provided on the inner arc surface of the connecting plate (65).

6. The spraying method of the low-pressure plasma spraying equipment according to any one of claims 1-5, characterized in that: Includes the following steps: Step 1: Place the workpiece (13) on the guide plate (62) of the pretreatment chamber (22). The linear moving device (41) in the low-pressure spraying chamber (23) moves the moving block towards one end of the partition (21) and brings the plug-in post (54) under the moving plate (43) close to the workpiece (13). It passes through the wiping sleeve (34) and the positioning pad (55) to insert the plug-in post (54) into the workpiece (13). The other end is used with the top plate (51) and the anti-slip pad (52) to clamp and fix the workpiece (13). Step 2: The two sets of linear moving devices (41) work synchronously, moving the moving plate (43) under the guide rail slider (42) and moving the workpiece (13) towards the low-pressure spraying chamber (23). At the same time, the motor (53) rotates in the forward direction, moving the plug-in column (54), workpiece (13) and top plate (51) axially. During the movement, the guide plate (62) cooperates with the ball (63) to assist in guiding and lifting. At the same time, the grinding belt (64) on the connecting plate (65) treats the circumferential side of the workpiece (13). Nitrogen gas is introduced through the air pipe (73) and moves along with the sprayed particles. Then, it is accelerated through the acceleration pipe (75) and sprayed out through the nozzle (76) to remove impurities from the surface of the workpiece (13). Step 3: After the impurity removal is completed, the linear moving device (41) continues to work, carrying the workpiece (13) to continue moving. The surface of the workpiece (13) can be wiped by the wiping sleeve (34), and then it moves to the low-pressure spraying chamber (23). The robotic arm (14) works to carry the plasma spraying device (15) to perform spraying operation on the workpiece (13). The particles that fall off during the spraying process are collected by the collection bucket (72). The filter screen (81) in the collection pipe (71) filters the particles of appropriate size and drops them down for subsequent spraying to remove impurities. The larger particles are discharged through the discharge pipe (82). Step 4: After the spraying and cooling are completed, the linear moving device (41) in the pretreatment chamber (22) moves and resets, the top plate (51) moves away from the workpiece (13), the workpiece (13) can be pulled, and the workpiece (13) is removed from the plug-in column (54) to complete the processing. When it is necessary to clean or replace the wiping sleeve (34), the plug-in plate (31) can be pulled, the card plate (33) slides in the card slot (32), and the plug-in plate (31) can be removed to facilitate the cleaning or replacement of the wiping sleeve (34).

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