Plasma Sprayed Structure of Metal Coating and Its Use Method

Abstract

The present invention relates to the technical field of plasma spraying, and discloses a plasma spraying structure for a metal coating and its usage method. The plasma spraying structure for the metal coating includes: a spraying chamber, a vacuum tube and an inert gas introduction tube are connected to the top of the spraying chamber; a clamping mechanism, the clamping mechanism includes a bidirectional screw rod, two mounting plates and two clamps, and connecting shafts are fixedly connected to one sides of the two clamps away from each other; a spraying mechanism, the spraying mechanism includes a mounting frame, a lead screw, an electric push rod, a plasma spray gun and a controller. The design of the present invention is reasonable. By means of the provided clamping mechanism and spraying mechanism, the workpiece can be driven to rotate while the plasma spray gun is driven to move to realize automatic spraying work, and the positions of the spray gun and the workpiece can be automatically adjusted during the spraying process by means of the provided controller and laser rangefinder, and the horizontal moving speed of the sub-spray gun and the rotating speed of the workpiece can be automatically adjusted according to the vertical moving speed of the spray gun to form a uniform coating.

Description

Technical Field

[0001] The present invention relates to the technical field of plasma spraying, and particularly to a plasma spraying structure for a metal coating and a method for using the same. Background Art

[0002] Plasma spraying is a technology for surface strengthening and surface modification of materials, which can endow the surface of the substrate with properties such as wear resistance, corrosion resistance, high-temperature oxidation resistance, electrical insulation, heat insulation, radiation protection, friction reduction, and sealing. The plasma spraying technology uses a plasma arc driven by direct current as a heat source to heat the powder material to a molten or semi-molten state and spray it onto the surface of the workpiece that has been pretreated at a high speed to form a firmly attached surface layer. The metal plasma coating is formed by heating the metal to a molten or semi-molten state by an electric arc and spraying it onto the workpiece.

[0003] Currently, the plasma gun position of the commonly used plasma spraying structure for metal coatings cannot be flexibly adjusted according to the workpiece, resulting in an uneven coating; therefore, we propose a plasma spraying structure for metal coatings and a method for using the same to solve this problem. Summary of the Invention

[0004] The purpose of the present invention is to solve the disadvantages that the plasma gun position of the commonly used plasma spraying structure for metal coatings cannot be flexibly adjusted according to the workpiece, resulting in an uneven coating, and to propose a plasma spraying structure for metal coatings and a method for using the same.

[0005] In order to achieve the above purpose, the present invention adopts the following technical scheme:

[0006] A plasma spraying structure for a metal coating, comprising:

[0007] A spraying chamber, the top of the spraying chamber is communicated with a vacuum tube and an inert gas introduction tube;

[0008] A clamping mechanism, the clamping mechanism includes a bidirectional screw, two mounting plates and two clamps. One side of each of the two clamps away from each other is fixedly connected with a connecting shaft. A rotating column is rotatably installed in the mounting plate. The rotating column is slidably sleeved outside the corresponding connecting shaft, and both of the mounting plates are threadedly sleeved outside the bidirectional screw;

[0009] Spraying mechanism, the spraying mechanism includes a mounting frame, a lead screw, an electric push rod, a plasma spray gun and a controller. A connecting plate is fixedly connected to the top of the mounting frame, the connecting plate is threadedly sleeved on the outside of the lead screw, the electric push rod is fixedly installed at the bottom of the mounting frame, and a lifting plate is fixedly connected to the output end of the electric push rod. The plasma spray gun and the controller are respectively fixedly installed at the bottom and top of the lifting plate, and laser rangefinders are fixedly installed on both sides of the bottom of the lifting plate. The laser rangefinders and the electric push rod are both electrically connected to the controller, and the controller controls the operation of the electric push rod according to the average value measured by the two laser rangefinders.

[0010] Preferably, three mounting holes are provided on both sides of the spraying chamber, and the lead screw, the bidirectional screw and the rotating column are respectively rotatably connected in the corresponding mounting holes;

[0011] A driven pulley is fixedly sleeved on the outside of the rotating column, a driving pulley is fixedly installed on the outside of the lead screw, and the same synchronous belt is installed on the driving pulley and the driven pulley on the same side;

[0012] A frame is fixedly installed on one side of the spraying chamber, a driving motor is fixedly installed on the top of the frame, and the output shaft of the driving motor is fixedly connected to one end of the lead screw;

[0013] A cross beam and a guide plate are fixedly installed inside the spraying chamber, the mounting plate is slidably sleeved on the outside of the cross beam, and both mounting plates are slidably sleeved on the outside of the guide plate.

[0014] Preferably, two resistance strips are fixedly installed on the front side of the mounting frame, a conductive block is slidably sleeved on the outside of the resistance strip, and the rear end of the resistance strip and the conductive block are connected in series into the circuit of the driving motor;

[0015] The same connecting plate is fixedly connected between the two conductive blocks. A rotating shaft is rotatably installed on the front side of the mounting frame. A rotating frame is fixedly installed at the front end of the rotating shaft. A cylinder is slidably sleeved on the outside of the rotating frame. The connecting plate is rotatably sleeved on the outside of the cylinder. A rotating plate is fixedly installed on the front side of the rotating frame. Two sliding seats are slidably sleeved on the outside of the rotating plate. Connecting ropes are fixedly connected to the sides of the two sliding seats close to each other. The rear ends of the two connecting ropes are fixedly connected to the front side of the cylinder.

[0016] Preferably, two limiting rings are fixedly sleeved on the outside of the cylinder, and the two limiting rings are respectively abutted against the front and rear sides of the connecting plate;

[0017] Two connecting springs are fixedly connected to the rear end of the cylinder, and the rear ends of the connecting springs are fixedly connected to the rear inner wall of the rotating frame;

[0018] Two fixed pulleys are rotatably installed inside the rotating frame, and the two connecting ropes are respectively wound around the outer sides of the corresponding fixed pulleys;

[0019] On one side of each of the two sliding seats away from each other, a compression spring is fixedly connected, and the other end of the compression spring is fixedly connected to the rotating plate;

[0020] A gear is fixedly installed on the rotating shaft, a vertical rod is fixedly installed on the top of the lifting plate, a rack is fixedly installed on one side of the vertical rod, and the gear meshes with the rack.

[0021] Preferably, a laser emitter and a laser receiver are provided at the bottom of the laser rangefinder;

[0022] A first control valve is provided on the vacuum tube, and a second control valve is provided on the inert gas inlet pipe.

[0023] Preferably, the fixture includes a mounting cylinder, a driving cylinder and a plurality of clamping plates. The mounting cylinder is fixedly connected to one end of the corresponding connecting shaft. The plurality of clamping plates are arranged at equal intervals in a ring shape. The outer sides of the clamping plates are rotatably connected with connecting rods and a plurality of mounting rods. Two adjacent mounting rods are parallel to each other, and the other ends of the mounting rods are rotatably connected to the inner wall of the mounting cylinder. The other end of the connecting rod is hinged with a cross bar. The driving cylinder is rotatably sleeved on the outside of the mounting cylinder, and a threaded cylinder is threadedly sleeved on the outside of the driving cylinder. The other end of the cross bar is fixedly connected to the threaded cylinder.

[0024] Preferably, a fixed ring is fixedly sleeved on the outside of the mounting cylinder, and the fixed ring is slidably sleeved on the outside of the plurality of cross bars;

[0025] An annular limiting protrusion is integrally formed on the outside of the mounting cylinder, and the annular limiting protrusion and the fixed ring are respectively movably abutted against both sides of the driving cylinder;

[0026] A square groove is opened on the left side of the mounting cylinder. A convex plate is slidably installed in the square groove. A plurality of grooves are opened on the inner wall of the driving cylinder. The convex plate is movably clamped in the corresponding groove. The bottom of the convex plate is fixedly connected with a return spring. The bottom end of the return spring is fixedly connected to the bottom inner wall of the square groove. A limiting rod is fixedly installed in the square groove, and the convex plate is slidably sleeved on the outside of the limiting rod.

[0027] Preferably, one end of the bidirectional screw is fixedly connected with a knob, a plurality of positioning grooves are formed in the outer side of the knob, a base is fixedly installed at the bottom of the spraying bin, a sliding groove is formed in one side of the top of the base, a sliding plate is slidably installed in the sliding groove, a positioning protrusion is integrally formed on the top of the sliding plate, the positioning protrusion is movably clamped in the corresponding positioning groove, and a pull rod and a transverse spring are fixedly connected to one side of the sliding plate, and the other end of the transverse spring is fixedly connected to the side wall of the sliding groove.

[0028] Preferably, a through hole is formed in the front side of the spraying bin, a baffle plate and two slide rails are fixedly installed on the front side of the spraying bin, the same bin door is slidably sleeved on the outer sides of the two slide rails, and the bin door is movably and hermetically abutted against the front side of the spraying bin;

[0029] A plurality of limiting grooves are formed in the outer side of the connecting shaft, and a plurality of limiting protrusions adapted to the limiting grooves are integrally formed on the inner wall of the rotating column.

[0030] The present invention also provides a use method of the above metal coating plasma spraying structure, including the following steps:

[0031] S1: Put the workpiece to be sprayed into the spraying bin through the through hole, clamp the workpiece through the clamping mechanism, and move the bin door downward to make it contact with the baffle plate, so as to block the through hole;

[0032] S2: Open the first control valve, extract gas through the vacuum tube to evacuate the spraying bin, then close the first control valve and open the second control valve, and fill the spraying bin with inert gas through the inert gas inlet pipe;

[0033] S3: Start the driving motor and the plasma spray gun. The plasma spray gun heats the metal powder to a molten state and sprays it onto the surface of the workpiece at a high speed to form a coating. At the same time, the driving motor drives the lead screw to rotate. The lead screw drives the mounting frame to move horizontally through the threaded transmission with the connecting plate and under the guidance of the cross beam, so as to drive the plasma spray gun arc to move horizontally. At the same time, the lead screw drives two driven pulleys to rotate through two driving pulleys and two synchronous belts, and drives the connecting shaft and the fixture to rotate through the rotating column, so as to drive the workpiece to rotate, so as to realize the spraying work on different positions of the workpiece;

[0034] S4: while spraying, the laser rangefinder is started, the laser transmitter emits laser to the workpiece, the laser receiver receives the laser, the distance between the workpiece and the lifting plate is calculated by the time difference, and the signal is transmitted to the controller, the controller takes the average value of the measurement results of the two laser rangefinders as the estimated distance between the plasma spray gun and the workpiece, when the estimated distance between the plasma spray gun and the workpiece decreases, the controller controls the output end of the electric push rod to contract, thereby driving the plasma spray gun away from the workpiece, when the estimated distance between the plasma spray gun and the workpiece increases, the controller controls the output end of the electric push rod to extend, thereby driving the plasma spray gun close to the workpiece, so that the distance between the plasma spray gun and the workpiece is always maintained within a constant range, ensuring uniform spraying;

[0035] S5: The electric push rod drives the lifting plate to lift the plate, and at the same time drives the vertical rod and the rack to lift synchronously. The rack drives the rotating shaft, the rotating frame and the rotating plate to rotate through the rotation of the gear, and drives the sliding seat to perform circular motion. The sliding seats move away from each other under the action of centrifugal force, and drive the cylinder forward through the connecting rope. The cylinder drives the connecting plate forward, and the connecting plate drives the two conductive blocks forward, so that the length of the resistor bar connected to the driving motor circuit increases, the resistance increases, so that the output shaft power of the driving motor is reduced, the driving speed is reduced, and the rotation speed of the rotating column and the lead screw is reduced. In order to reduce the horizontal movement speed of the plasma spray gun and the rotation speed of the workpiece, the spraying feed speed can be increased when the workpiece undergoes shape changes to ensure complete and uniform spraying. As the shape of the workpiece changes, the up and down movement speed of the lifting plate increases, the movement speed of the rotating frame increases, the centrifugal force on the sliding seat increases, the moving distance of the sliding seat increases, and the moving distance of the cylinder and the conductor increases, thereby further increasing the length of the resistor bar connected to the drive motor circuit and further reducing the resistance, thereby further reducing the horizontal movement speed of the spray gun and the rotation speed of the workpiece to ensure uniformity of spraying.

[0036] Compared with the prior art, the present invention provides a metal coating plasma spraying structure and a method of using the same, which have the following beneficial effects:

[0037] (1) Place the workpiece to be sprayed into the spraying chamber through the through-hole. Pull the pull rod to drive the sliding plate to move horizontally, so that the positioning protrusion disengages from the positioning groove, releasing the fixation of the knob. Then rotate the knob to drive the bidirectional screw to rotate. The bidirectional screw drives the two mounting plates to approach each other through the threaded transmission with the two mounting plates and under the guidance of the guide plate. The two mounting plates drive the two clamps to approach each other, thereby adjusting the distance between the two clamps according to the length of the workpiece. Then release the pull rod, so that the sliding plate locks the knob. Next, push the convex plate to make it disengage from the groove, and then rotate the driving cylinder to drive the threaded cylinder to move horizontally through the threaded transmission with the threaded cylinder. The threaded cylinder drives the multiple clamping plates located in the same mounting cylinder to approach each other through the cooperation of the cross bar and the connecting rod, realizing the clamping work of the workpiece. Then release the convex plate to make it move reversely under the action of the return spring and insert into the groove to lock the driving cylinder to ensure the clamping stability;

[0038] (2) By moving the chamber door downward to make it contact the baffle plate, thereby blocking the through-hole. Open the first control valve, and extract gas through the vacuum tube to evacuate the spraying chamber. Then close the first control valve and open the second control valve, and fill the spraying chamber with inert gas through the inert gas inlet pipe, so that the spraying process can be protected by the inert gas, reducing the generation of oxides, maintaining the chemical composition and purity of the coating. The oxygen-free environment provided by the inert gas is conducive to the adhesion between the coating and the substrate, avoiding the decrease in adhesion caused by the oxide layer, and the inert gas can reduce the chance for operators to contact harmful gases and dust, thereby protecting the health of the operators;

[0039] (3) By starting the driving motor and the plasma spray gun, the plasma spray gun heats the metal powder to the molten state and sprays it onto the surface of the workpiece at a high speed to form a coating. At the same time, the driving motor drives the lead screw to rotate. The lead screw drives the mounting frame to move horizontally through the threaded transmission with the connecting plate and under the guidance of the cross beam, thereby driving the plasma spray gun arc to move horizontally. At the same time, the lead screw drives the two driven pulleys to rotate through the two driving pulleys and the two synchronous belts, and drives the connecting shaft and the clamp to rotate through the rotating column, thereby driving the workpiece to rotate to realize the spraying work on different positions of the workpiece;

[0040] (4) While spraying, start the laser rangefinder. The laser emitter emits laser light towards the workpiece, and the laser receiver receives the laser. The distance between the workpiece and the lifting plate is measured through the time difference, and the signal is transmitted to the controller. The controller takes the average value of the measurement results of the two laser rangefinders as the estimated distance between the plasma spray gun and the workpiece. When the estimated distance between the plasma spray gun and the workpiece decreases, the controller controls the output end of the electric push rod to contract, thereby driving the plasma spray gun away from the workpiece. When the estimated distance between the plasma spray gun and the workpiece increases, the controller controls the output end of the electric push rod to extend, thereby driving the plasma spray gun closer to the workpiece, so that the distance between the plasma spray gun and the workpiece is always maintained within a constant range, and the horizontal movement speed of the plasma spray gun and the rotation speed of the workpiece can be reduced while the plasma spray gun is moving, ensuring uniform spraying.

[0041] (5) Through the set clamping mechanism and spraying mechanism, the plasma spray gun can be driven to move while driving the workpiece to rotate to achieve automatic spraying work. And through the set controller and laser rangefinder, the position of the spray gun and the workpiece can be automatically adjusted during spraying, and the horizontal movement speed of the sub-spray gun and the rotation speed of the workpiece can be automatically adjusted according to the vertical movement speed of the spray gun to form a uniform coating. Description of the Drawings

[0042] Figure 1 Schematic three-dimensional structure diagram of the metal coating plasma spraying structure proposed by the present invention;

[0043] Figure 2 Schematic cross-sectional structure diagram of the metal coating plasma spraying structure proposed by the present invention;

[0044] Figure 3 is Figure 2 Partial enlarged view of part A in

[0045] Figure 4 is Figure 2 Partial enlarged view of part B in

[0046] Figure 5 Schematic partial three-dimensional structure diagram of the metal coating plasma spraying structure proposed by the present invention;

[0047] Figure 6 Schematic partial three-dimensional structure diagram of the clamping mechanism proposed by the present invention;

[0048] Figure 7 Schematic three-dimensional structure diagram of the fixture proposed by the present invention;

[0049] Figure 8 Schematic cross-sectional structure diagram of the fixture proposed by the present invention;

[0050] Figure 9 is Figure 8Partial enlarged view of part C;

[0051] Figure 10 Schematic perspective view of the spraying mechanism proposed by the present invention;

[0052] Figure 11 Schematic perspective view of the spraying mechanism proposed by the present invention;

[0053] Figure 12 is Figure 11 Partial enlarged view of the structure in;

[0054] Figure 13 is Figure 12 Top view cross-sectional view of the structure in;

[0055] Figure 14 is Figure 13 Partial enlarged view of part D in.

[0056] In the figure: 1, spraying chamber; 101, base; 102, chamber door; 103, slide rail; 104, baffle; 105, vacuum tube; 106, inert gas inlet pipe; 107, first control valve; 108, second control valve; 2, mounting cylinder; 201, clamping plate; 202, mounting rod; 203, connecting rod; 204, cross bar; 205, fixing ring; 206, threaded cylinder; 207, driving cylinder; 208, convex plate; 209, return spring; 3, mounting plate; 301, guide plate; 302, bidirectional screw; 303, knob; 304, sliding plate; 305, transverse spring; 306, pull rod; 4, connecting shaft; 401, driven belt pulley; 402, driving belt pulley; 403, rotating column; 5, mounting frame; 501, cross beam; 502, lead screw; 503, driving motor; 504, connecting plate; 6, electric push rod; 7, lifting plate; 8, plasma spray gun; 9, laser range finder; 901, laser emitter; 902, laser receiver; 10, controller; 11, vertical rod; 12, rack; 13, gear; 14, resistance strip; 15, conductive block; 16, connecting plate; 17, rotating frame; 18, rotating plate; 19, compression spring; 20, sliding seat; 21, rotating shaft; 22, connecting spring; 23, cylinder; 24, connecting rope; 25, fixed pulley; 26, limiting ring. Detailed implementation manners

[0057] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0058] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0059] Referring to Figure 1-14 , the plasma spraying structure of the metal coating includes:

[0060] A spraying chamber 1, the top of the spraying chamber 1 is communicated with a vacuum tube 105 and an inert gas introduction tube 106;

[0061] A clamping mechanism, the clamping mechanism includes a bidirectional screw 302, two mounting plates 3 and two clamps. On the side of the two clamps away from each other, a connecting shaft 4 is fixedly connected. A rotating column 403 is rotatably installed in the mounting plate 3. The rotating column 403 is slidably sleeved on the outer side of the corresponding connecting shaft 4, and the two mounting plates 3 are both threadedly sleeved on the outer side of the bidirectional screw 302;

[0062] A spraying mechanism, the spraying mechanism includes a mounting frame 5, a lead screw 502, an electric push rod 6, a plasma spray gun 8 and a controller 10. A connecting plate 504 is fixedly connected to the top of the mounting frame 5. The connecting plate 504 is threadedly sleeved on the outer side of the lead screw 502. The electric push rod 6 is fixedly installed at the bottom of the mounting frame 5, and a lifting plate 7 is fixedly connected to the output end of the electric push rod 6. The plasma spray gun 8 and the controller 10 are respectively fixedly installed at the bottom and the top of the lifting plate 7, and laser rangefinders 9 are fixedly installed on both sides of the bottom of the lifting plate 7. The laser rangefinders 9 and the electric push rod 6 are both electrically connected to the controller 10. The controller 10 controls the operation of the electric push rod 6 according to the average value measured by the two laser rangefinders 9.

[0063] In this embodiment, three mounting holes are provided on both sides of the spraying chamber 1. The lead screw 502, the bidirectional screw 302, and the rotating column 403 are respectively rotatably connected in the corresponding mounting holes, so as to realize the rotational positioning of the lead screw 502, the bidirectional screw 302, and the rotating column 403. A driven pulley 401 is fixedly sleeved on the outer side of the rotating column 403, and a driving pulley 402 is fixedly installed on the outer side of the lead screw 502. The same synchronous belt is installed on the driving pulley 402 and the driven pulley 401 on the same side to ensure stable transmission. A frame is fixedly installed on one side of the spraying chamber 1, and a driving motor 503 is fixedly installed on the top of the frame. The output shaft of the driving motor 503 is fixedly connected to one end of the lead screw 502, so as to drive the lead screw 502 to rotate. A cross beam 501 and a guide plate 301 are fixedly installed inside the spraying chamber 1. The mounting plate 3 is slidably sleeved on the outer side of the cross beam 501, and both mounting plates 3 are slidably sleeved on the outer side of the guide plate 301, so as to guide the horizontal movement of the mounting plate 3. Two resistance strips 14 are fixedly installed on the front side of the mounting frame 5. A conductive block 15 is slidably sleeved on the outer side of the resistance strip 14. The rear end of the resistance strip 14 and the conductive block 15 are connected in series to the circuit of the driving motor 503. The same connecting plate 16 is fixedly connected between the two conductive blocks 15. A rotating shaft 21 is rotatably installed on the front side of the mounting frame 5. A rotating frame 17 is fixedly installed at the front end of the rotating shaft 21. A cylinder 23 is slidably sleeved on the outer side of the rotating frame 17. The connecting plate 16 is rotatably sleeved on the outer side of the cylinder 23. A rotating plate 18 is fixedly installed on the front side of the rotating frame 17. Two sliding seats 20 are slidably sleeved on the outer side of the rotating plate 18. A connecting rope 24 is fixedly connected to each side of the two sliding seats 20 close to each other. The rear ends of the two connecting ropes 24 are fixedly connected to the front side of the cylinder 23.

[0064] In this embodiment, two limit rings 26 are fixedly sleeved on the outer side of the cylinder 23. The two limit rings 26 are respectively movably abutted against the front and rear sides of the connection plate 16, so that the connection plate 16 and the cylinder 23 move synchronously back and forth through the limit rings 26. Two connection springs 22 are fixedly connected to the rear end of the cylinder 23. The rear ends of the connection springs 22 are fixedly connected to the rear inner wall of the rotating frame 17, so as to reset the cylinder 23 and position it in the initial state. Two fixed pulleys 25 are rotatably installed in the rotating frame 17. The two connection ropes 24 are respectively wound around the outer sides of the corresponding fixed pulleys 25, so as to guide the connection ropes 24. Compression springs 19 are fixedly connected to the mutually remote sides of the two sliding seats 20. The other ends of the compression springs 19 are fixedly connected to the rotating plate 18. A gear 13 is fixedly installed on the rotating shaft 21. A vertical rod 11 is fixedly installed on the top of the lifting plate 7. A rack 12 is fixedly installed on one side of the vertical rod 11. The gear 13 meshes with the rack 12, so that the rotation of the rotating shaft 21 can be driven by the up and down movement of the lifting plate 7. A laser emitter 901 and a laser receiver 902 are arranged at the bottom of the laser rangefinder 9. A first control valve 107 is arranged on the vacuum tube 105, and a second control valve 108 is arranged on the inert gas inlet pipe 106, so as to facilitate the control of the on-off of the vacuum tube 105 and the inert gas inlet pipe 106.

[0065] In this embodiment, the fixture includes a mounting cylinder 2, a driving cylinder 207, and a plurality of clamping plates 201. The mounting cylinder 2 is fixedly connected to one end of the corresponding connecting shaft 4. The plurality of clamping plates 201 are arranged at equal intervals in a ring shape. The outer side of the clamping plate 201 is rotatably connected with a connecting rod 203 and a plurality of mounting rods 202. Two adjacent mounting rods 202 are parallel to each other, and the other end of the mounting rod 202 is rotatably connected to the inner wall of the mounting cylinder 2. The other end of the connecting rod 203 is hinged with a cross bar 204. The driving cylinder 207 is rotatably sleeved on the outer side of the mounting cylinder 2, and a threaded cylinder 206 is threadedly sleeved on the outer side of the driving cylinder 207. The other end of the cross bar 204 is fixedly connected to the threaded cylinder 206. A fixed ring 205 is fixedly sleeved on the outer side of the mounting cylinder 2. The fixed ring 205 is slidably sleeved on the outer sides of the plurality of cross bars 204, thereby guiding the cross bars 204. An annular limiting projection is integrally formed on the outer side of the mounting cylinder 2. The annular limiting projection and the fixed ring 205 are respectively abutted against both sides of the driving cylinder 207, thereby performing the limiting work on the horizontal movement of the driving cylinder 207. A square groove is formed on the left side of the mounting cylinder 2. A convex plate 208 is slidably mounted in the square groove. A plurality of grooves are formed on the inner wall of the driving cylinder 207. The convex plate 208 is movably clamped in the corresponding groove. The bottom of the convex plate 208 is fixedly connected to a return spring 209. The bottom end of the return spring 209 is fixedly connected to the bottom inner wall of the square groove. A limiting rod is fixedly installed in the square groove. The convex plate 208 is slidably sleeved on the outer side of the limiting rod, thereby guiding the convex plate 208. One end of a bidirectional screw 302 is fixedly connected to a knob 303. A plurality of positioning grooves are formed on the outer side of the knob 303. A base 101 is fixedly installed at the bottom of the spraying chamber 1. A chute is formed on one side of the top of the base 101. A sliding plate 304 is slidably mounted in the chute. A positioning projection is integrally formed on the top of the sliding plate 304. The positioning projection is movably clamped in the corresponding positioning groove. One side of the sliding plate 304 is fixedly connected to a pull rod 306 and a transverse spring 305. The other end of the transverse spring 305 is fixedly connected to the side wall of the chute, thereby resetting the sliding plate 304.

[0066] In this embodiment, a through hole is formed on the front side of the spraying chamber 1, which is convenient for taking and placing workpieces. A baffle 104 and two slide rails 103 are fixedly installed on the front side of the spraying chamber 1. The same chamber door 102 is slidably sleeved on the outer sides of the two slide rails 103. The chamber door 102 is movably and sealingly abutted against the front side of the spraying chamber 1, thereby blocking the through hole. A plurality of limiting grooves are formed on the outer side of the connecting shaft 4. A plurality of limiting projections adapted to the limiting grooves are integrally formed on the inner wall of the rotating column 403, so that the connecting shaft 4 and the rotating column 403 rotate synchronously.

[0067] This embodiment also provides a usage method of the above metal coating plasma spraying structure, including the following steps:

[0068] S1: Place the workpiece to be sprayed into the spraying chamber 1 through the through-hole, clamp the workpiece by the clamping mechanism, and seal the through-hole by moving the chamber door 102 downward until it contacts the baffle 104.

[0069] S2: Open the first control valve 107, extract gas through the vacuum tube 105 to evacuate the spraying chamber 1, then close the first control valve 107 and open the second control valve 108 to fill the spraying chamber 1 with inert gas through the inert gas inlet pipe 106.

[0070] S3: Start the drive motor 503 and the plasma spray gun 8. The plasma spray gun 8 heats the metal powder to a molten state and sprays it onto the surface of the workpiece at high speed to form a coating. At the same time, the drive motor 503 drives the lead screw 502 to rotate. The lead screw 502 drives the mounting frame 5 to move horizontally through the threaded drive with the connecting plate 504 and under the guidance of the cross beam 501, thereby driving the plasma spray gun 8 to move horizontally. At the same time, the lead screw 502 drives the two driven pulleys 401 to rotate through the two driving pulleys 402 and the two synchronous belts, and drives the connecting shaft 4 and the fixture to rotate through the rotating column 403, thereby driving the workpiece to rotate to achieve spraying work on different positions of the workpiece.

[0071] S4: Start the laser rangefinder 9 while spraying. The laser emitter 901 emits laser light to the workpiece, and the laser receiver 902 receives the laser light. Calculate the distance between the workpiece and the lifting plate 7 through the time difference and transmit the signal to the controller 10. The controller 10 takes the average value of the measurement results of the two laser rangefinders 9 as the distance estimate between the plasma spray gun 8 and the workpiece. When the distance estimate between the plasma spray gun 8 and the workpiece decreases, the controller 10 controls the output end of the electric push rod 6 to contract, thereby driving the plasma spray gun 8 away from the workpiece. When the distance estimate between the plasma spray gun 8 and the workpiece increases, the controller 10 controls the output end of the electric push rod 6 to extend, thereby driving the plasma spray gun 8 closer to the workpiece, so that the distance between the plasma spray gun 8 and the workpiece is always maintained within a constant range, ensuring uniform spraying.

[0072] S5: The electric push rod 6 drives the lifting plate 7 to move up and down. While the lifting plate 7 is moving, it drives the vertical rod 11 and the rack 12 to move up and down synchronously. The rack 12 drives the rotation of the rotating shaft 21, the rotating frame 17 and the rotating plate 18 through the rotation of the gear 13, and drives the sliding seat 20 to perform a circular motion. The sliding seats 20 move away from each other under the action of centrifugal force, and drive the cylinder 23 to move forward through the connecting rope 24. The cylinder 23 drives the connecting plate 16 to move forward, and the connecting plate 16 drives the two conductive blocks 15 to move forward. As a result, the length of the resistance strip 14 connected to the driving motor 503 circuit increases and the resistance increases, so that the output shaft power of the driving motor 503 decreases and the driving speed decreases, thereby reducing the rotation speeds of the rotating column 403 and the lead screw 502, reducing the horizontal moving speed of the plasma spray gun 8 and the rotating speed of the workpiece, so that the spraying feed speed can be increased in the stage when the workpiece has a shape change to ensure complete and uniform spraying. And as the shape change of the workpiece increases, the up and down moving speed of the lifting plate 7 increases, the moving speed of the rotating frame 17 increases, the centrifugal force received by the sliding seat 20 increases, the moving distance of the sliding seat 20 increases, and the moving distances of the cylinder 23 and the conductor increase, so that the length of the resistance strip 14 connected to the driving motor 503 circuit further increases and the resistance further decreases, further reducing the horizontal moving speed of the spray gun and the rotating speed of the workpiece to ensure the uniformity of spraying.

[0073] In this embodiment, during use, the workpiece to be sprayed is placed into the spraying chamber 1 through the through hole. Pull the pull rod 306 to drive the sliding plate 304 to move horizontally so that the positioning protrusion disengages from the positioning groove, releasing the fixation of the knob 303. Then rotate the knob 303 to drive the rotation of the bidirectional screw rod 302. The bidirectional screw rod 302 drives the two mounting plates 3 to approach each other through the threaded transmission with the two mounting plates 3 and under the guidance of the guide plate 301. The two mounting plates 3 drive the two clamps to approach each other, thereby adjusting the distance between the two clamps according to the length of the workpiece. Then release the pull rod 306 so that the sliding plate 304 locks the knob 303. Then push the convex plate 208 to disengage it from the groove, and then rotate the driving cylinder 207 to drive the threaded cylinder 206 to move horizontally through the threaded transmission with the threaded cylinder 206. The threaded cylinder 206 drives the multiple clamping plates 201 located in the same mounting cylinder 2 to approach each other through the cooperation of the cross bar 204 and the connecting rod 203, realizing the clamping work of the workpiece. Then release the convex plate 208 so that it moves reversely under the action of the return spring 209 and inserts into the groove to lock the driving cylinder 207 to ensure the clamping stability;

[0074] By moving the hatch 102 downward so that it contacts the baffle 104, the through-hole is blocked. By opening the first control valve 107, the gas is pumped out through the vacuum tube 105 to evacuate the spraying chamber 1. Then, the first control valve 107 is closed and the second control valve 108 is opened, and inert gas is filled into the spraying chamber 1 through the inert gas inlet pipe 106. Thus, the spraying process can be protected by the inert gas, the generation of oxides can be reduced, the chemical composition and purity of the coating can be maintained. The oxygen-free environment provided by the inert gas is beneficial to the adhesion between the coating and the substrate, avoiding the decrease in adhesion caused by the oxide layer. Moreover, the inert gas can reduce the opportunity for operators to contact harmful gases and dust, thereby protecting the health of the operators;

[0075] By starting the drive motor 503 and the plasma spray gun 8, the plasma spray gun 8 heats the metal powder to the molten state and sprays it onto the surface of the workpiece at a high speed to form a coating. At the same time, the drive motor 503 drives the lead screw 502 to rotate. The lead screw 502 drives the mounting frame 5 to move horizontally through the threaded drive with the connecting plate 504 and under the guidance of the cross beam 501, thereby driving the plasma spray gun 8 to move horizontally. At the same time, the lead screw 502 drives two driven pulleys 401 to rotate through two driving pulleys 402 and two synchronous belts, and drives the connecting shaft 4 and the fixture to rotate through the rotating column 403, thereby driving the workpiece to rotate, so as to realize the spraying work on different positions of the workpiece;

[0076] By starting the laser rangefinder 9 while spraying, the laser emitter 901 emits laser to the workpiece, and the laser receiver 902 receives the laser. The distance between the workpiece and the lifting plate 7 is calculated through the time difference, and the signal is transmitted to the controller 10. The controller 10 takes the average value of the measurement results of the two laser rangefinders 9 as the distance estimation value between the plasma spray gun 8 and the workpiece. When the distance estimation value between the plasma spray gun 8 and the workpiece decreases, the controller 10 controls the output end of the electric push rod 6 to contract, thereby driving the plasma spray gun 8 away from the workpiece. When the distance estimation value between the plasma spray gun 8 and the workpiece increases, the controller 10 controls the output end of the electric push rod 6 to extend, thereby driving the plasma spray gun 8 closer to the workpiece, so that the distance between the plasma spray gun 8 and the workpiece is always maintained within a constant range, and the horizontal movement speed of the plasma spray gun 8 and the rotation speed of the workpiece can be reduced while the plasma spray gun 8 is moving, ensuring uniform spraying.

[0077] The standard parts used in the present invention can all be purchased from the market. The special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, and welding that are mature in the prior art. The machines, parts, and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be elaborated here.

Claims

1. A plasma spraying structure of a metal coating, characterized in that, Including: A spraying chamber (1), the top of the spraying chamber (1) is communicated with a vacuum tube (105) and an inert gas introduction tube (106); A clamping mechanism, the clamping mechanism includes a bidirectional screw (302), two mounting plates (3) and two clamps. On one side of each of the two clamps away from each other, a connecting shaft (4) is fixedly connected. A rotating column (403) is rotatably installed in the mounting plate (3), the rotating column (403) is slidably sleeved on the outer side of the corresponding connecting shaft (4), and the two mounting plates (3) are both threadedly sleeved on the outer side of the bidirectional screw (302); A spraying mechanism, the spraying mechanism includes a mounting frame (5), a lead screw (502), an electric push rod (6), a plasma spray gun (8) and a controller (10). A connecting plate (504) is fixedly connected to the top of the mounting frame (5), the connecting plate (504) is threadedly sleeved on the outer side of the lead screw (502), the electric push rod (6) is fixedly installed at the bottom of the mounting frame (5), and a lifting plate (7) is fixedly connected to the output end of the electric push rod (6). The plasma spray gun (8) and the controller (10) are respectively fixedly installed at the bottom and the top of the lifting plate (7), and laser rangefinders (9) are fixedly installed on both sides of the bottom of the lifting plate (7). The laser rangefinders (9) and the electric push rod (6) are both electrically connected to the controller (10). The controller (10) controls the operation of the electric push rod (6) according to the average value measured by the two laser rangefinders (9). Two resistance strips (14) are fixedly installed on the front side of the mounting frame (5), a conductive block (15) is slidably sleeved on the outer side of the resistance strip (14). One side of the spraying chamber (1) is fixedly installed with a frame, and a driving motor (503) is fixedly installed on the top of the frame. The rear end of the resistance strip (14) and the conductive block (15) are connected in series to the circuit of the driving motor (503); A same connection plate (16) is fixedly connected between the two conductive blocks (15). A rotating shaft (21) is rotatably installed on the front side of the mounting frame (5), a rotating frame (17) is fixedly installed at the front end of the rotating shaft (21), a cylinder (23) is slidably sleeved on the outer side of the rotating frame (17), the connection plate (16) is rotatably sleeved on the outer side of the cylinder (23), a rotating plate (18) is fixedly installed on the front side of the rotating frame (17), two sliding seats (20) are slidably sleeved on the outer side of the rotating plate (18), and a connection rope (24) is fixedly connected to one side of each of the two sliding seats (20) close to each other. The rear ends of the two connection ropes (24) are both fixedly connected to the front side of the cylinder (23).

2. The plasma spraying structure of the metal coating according to claim 1, characterized in that, Three mounting holes are respectively opened on both sides of the spraying chamber (1), and the lead screw (502), the bidirectional screw (302) and the rotating column (403) are respectively rotatably connected in the corresponding mounting holes; A driven pulley (401) is fixedly sleeved on the outer side of the rotating column (403), a driving pulley (402) is fixedly installed on the outer side of the screw rod (502), and the driving pulley (402) and the driven pulley (401) on the same side are driven and installed with the same synchronous belt; The output shaft of the driving motor (503) is fixedly connected to one end of the screw rod (502); A crossbeam (501) and a guide plate (301) are fixedly installed inside the spray chamber (1); the mounting plate (3) is slidably sleeved on the outside of the crossbeam (501), and both mounting plates (3) are slidably sleeved on the outside of the guide plate (301).

3. The plasma spraying structure of the metal coating according to claim 2, wherein Two limiting rings (26) are fixedly sleeved on the outer side of the cylinder (23), and the two limiting rings (26) are movably abutted against the front and rear sides of the connecting plate (16) respectively; Two connecting springs (22) are fixedly connected to the rear end of the cylinder (23), and the rear ends of the connecting springs (22) are fixedly connected to the rear inner wall of the rotating frame (17); Two fixed pulleys (25) are rotatably mounted in the rotating frame (17), and the two connecting ropes (24) are respectively wound around the outer sides of the corresponding fixed pulleys (25); The two sliding seats (20) are both fixedly connected to a compression spring (19) on one side away from each other, and the other end of the compression spring (19) is fixedly connected to the rotating plate (18); A gear (13) is fixedly mounted on the rotating shaft (21), a vertical rod (11) is fixedly mounted on the top of the lifting plate (7), a rack (12) is fixedly mounted on one side of the vertical rod (11), and the gear (13) is meshed with the rack (12).

4. The metal coating plasma spraying structure according to claim 3, characterized in that, A laser transmitter (901) and a laser receiver (902) are provided at the bottom of the laser rangefinder (9); The vacuum tube (105) is provided with a first control valve (107), and the inert gas introduction tube (106) is provided with a second control valve (108).

5. The metal coating plasma spraying structure according to claim 4, wherein, The clamp comprises a mounting cylinder (2), a driving cylinder (207) and a plurality of clamping plates (201); the mounting cylinder (2) is fixedly connected to one end of the corresponding connecting shaft (4); the plurality of clamping plates (201) are arranged in a ring shape at equal intervals; the outer side of the clamping plate (201) is rotatably connected to a connecting rod (203) and a plurality of mounting rods (202); two adjacent mounting rods (202) are parallel to each other; the other ends of the mounting rods (202) are rotatably connected to the inner wall of the mounting cylinder (2); the other end of the connecting rod (203) is hinged to a cross rod (204); the driving cylinder (207) is rotatably sleeved on the outer side of the mounting cylinder (2); the outer side of the driving cylinder (207) is threadedly sleeved with a threaded cylinder (206); the other end of the cross rod (204) is fixedly connected to the threaded cylinder (206).

6. The metal coating plasma spraying structure according to claim 5, wherein, A fixing ring (205) is fixedly sleeved on the outer side of the installation cylinder (2), and the fixing ring (205) is slidably sleeved on the outer sides of the plurality of cross bars (204); An annular limiting protrusion is integrally formed on the outer side of the installation cylinder (2), and the annular limiting protrusion and the fixing ring (205) are respectively in movable abutment against both sides of the driving cylinder (207); A square groove is formed on the left side of the installation cylinder (2), a convex plate (208) is slidably installed in the square groove, a plurality of grooves are formed on the inner wall of the driving cylinder (207), the convex plate (208) is movably clamped in the corresponding groove, and the bottom of the convex plate (208) is fixedly connected with a return spring (209), the bottom end of the return spring (209) is fixedly connected with the bottom inner wall of the square groove, and a limiting rod is fixedly installed in the square groove, and the convex plate (208) is slidably sleeved on the outer side of the limiting rod.

7. The plasma spraying structure of the metal coating according to claim 6, wherein One end of the bidirectional screw rod (302) is fixedly connected with a knob (303), a plurality of positioning grooves are formed on the outer side of the knob (303), a base (101) is fixedly installed at the bottom of the spraying chamber (1), a sliding groove is formed on one side of the top of the base (101), a sliding plate (304) is slidably installed in the sliding groove, a positioning protrusion is integrally formed on the top of the sliding plate (304), the positioning protrusion is movably clamped in the corresponding positioning groove, and a pull rod (306) and a transverse spring (305) are fixedly connected to one side of the sliding plate (304), and the other end of the transverse spring (305) is fixedly connected with the side wall of the sliding groove.

8. The plasma spraying structure of the metal coating according to claim 7, characterized in that, A through hole is formed on the front side of the spraying chamber (1), and a baffle plate (104) and two slide rails (103) are fixedly installed on the front side of the spraying chamber (1), and the same chamber door (102) is slidably sleeved on the outer sides of the two slide rails (103), and the chamber door (102) is in movable sealing abutment against the front side of the spraying chamber (1); A plurality of limiting grooves are formed on the outer side of the connecting shaft (4), and a plurality of limiting protrusions adapted to the limiting grooves are integrally formed on the inner wall of the rotating column (403).

9. A method for using a plasma spraying structure of a metal coating as described in any one of claims 1-8, characterized in that, Including the following steps: S1: Place the workpiece to be sprayed into the spraying chamber (1) through the through hole, clamp the workpiece through the clamping mechanism, and move the chamber door (102) downward to make it contact with the baffle plate (104), so as to block the through hole; S2: Open the first control valve (107), extract gas through the vacuum tube (105) to evacuate the spraying chamber (1), then close the first control valve (107) and open the second control valve (108), and fill the spraying chamber (1) with inert gas through the inert gas introduction pipe (106); S3: Start the drive motor (503) and the plasma spray gun (8). The plasma spray gun (8) heats the metal powder to a molten state and sprays it onto the surface of the workpiece at a high speed to form a coating. At the same time, the drive motor (503) drives the lead screw (502) to rotate. The lead screw (502) drives the mounting frame (5) to move horizontally through the threaded drive with the connecting plate (504) and under the guidance of the cross beam (501), thereby driving the plasma spray gun (8) to move horizontally in an arc. At the same time, the lead screw (502) drives two driven pulleys (401) to rotate through two driving pulleys (402) and two synchronous belts, and drives the connecting shaft (4) and the fixture to rotate through the rotating column (403), thereby driving the workpiece to rotate, so as to realize the spraying operation at different positions of the workpiece; S4: While spraying, start the laser rangefinder (9). The laser emitter (901) emits laser to the workpiece, and the laser receiver (902) receives the laser. The distance between the workpiece and the lifting plate (7) is calculated through the time difference, and the signal is transmitted to the controller (10). The controller (10) takes the average value of the measurement results of the two laser rangefinders (9) as the distance estimate between the plasma spray gun (8) and the workpiece. When the distance estimate between the plasma spray gun (8) and the workpiece decreases, the controller (10) controls the output end of the electric push rod (6) to contract, thereby driving the plasma spray gun (8) away from the workpiece. When the distance estimate between the plasma spray gun (8) and the workpiece increases, the controller (10) controls the output end of the electric push rod (6) to extend, thereby driving the plasma spray gun (8) closer to the workpiece, so that the distance between the plasma spray gun (8) and the workpiece is always maintained within a constant range, ensuring uniform spraying; S5: The electric push rod (6) drives the lifting plate (7) to move up and down. While the lifting plate (7) moves, it drives the vertical rod (11) and the rack (12) to move up and down synchronously. The rack (12) drives the rotation of the rotating shaft (21), the rotating frame (17) and the rotating plate (18) through the rotation of the gear (13), and drives the sliding seat (20) to perform a circular motion. The sliding seats (20) move away from each other under the action of centrifugal force, and drive the cylinder (23) to move forward through the connecting rope (24). The cylinder (23) drives the connecting plate (16) to move forward, and the connecting plate (16) drives the two conductive blocks (15) to move forward, so that the length of the resistance bar (14) connected to the circuit of the drive motor (503) increases and the resistance increases. As a result, the output shaft power of the drive motor (503) decreases and the driving speed decreases, thereby reducing the rotation speeds of the rotating column (403) and the lead screw (502), so as to reduce the horizontal movement speed of the plasma spray gun (8) and the rotation speed of the workpiece, so that the spraying feed speed can be increased at the stage when the shape of the workpiece changes, so as to ensure complete and uniform spraying. Moreover, as the shape change of the workpiece increases, the up and down movement speed of the lifting plate (7) increases, the movement speed of the rotating frame (17) increases, the centrifugal force received by the sliding seat (20) increases, the moving distance of the sliding seat (20) increases, and the moving distances of the cylinder (23) and the conductive block increase, so that the length of the resistance bar (14) connected to the circuit of the drive motor (503) further increases and the resistance further decreases, thereby further reducing the horizontal movement speed of the spray gun and the rotation speed of the workpiece and ensuring the uniformity of spraying.

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