Three-electrode plasma spraying device

Abstract

The invention discloses a three-electrode plasma spraying device which comprises a mechanical arm, a spray gun and a wave fluctuation type base plane, the mechanical arm is used for driving the spray gun and controlling the distance and perpendicularity between the spray gun and the wave fluctuation type base plane, a nozzle anode and a tungsten rod cathode are arranged on the spray gun, and the tungsten rod cathode is axially installed in the center of the nozzle anode. The tungsten rod cathode is provided with an axial driving mechanism used for adjusting the distance between the tungsten rod cathode and the waved base plane. The device is suitable for a workpiece with a waved base surface, the position of the tungsten rod cathode can be axially adjusted, the distance between the tungsten rod cathode and a to-be-machined surface is kept at the minimum distance relative to the distance between the tungsten rod cathode and other surfaces, a molten pool is consistent with the to-be-machined surface, then a coating is compact and high in adhesive force, and the spraying quality is improved.

Description

Technical Field

[0001] The invention relates to a three-electrode plasma spraying device. Background Art

[0002] Three-electrode plasma spraying technology is a method of spraying materials using high-temperature plasma. Its spraying equipment includes three parts: nozzle anode, auxiliary cathode and workpiece anode. During the spraying process, one power source is added between the nozzle anode and the auxiliary cathode to generate a non-transferred ion arc, which is used to ignite and heat the metal powder. Another power source is added between the workpiece anode and the auxiliary cathode to generate a transferred ion arc, which is used to heat the workpiece to produce a molten pool on the surface to be processed.

[0003] In the process of processing a workpiece with a wavy base surface, the spray gun adjusts its position and orientation in real time through the robot, so that the distance and verticality between the spray gun and the surface to be processed are always consistent. When the spray gun moves to the trough section, the spray gun can penetrate into the trough according to the spacing requirements, and the auxiliary cathode follows the spray gun to move into the trough, which may cause the distance between the auxiliary cathode and the curved surfaces on both sides to be smaller than the distance between the auxiliary cathode and the surface to be processed. Since the transferred ion arc will be formed along the shortest path between the two electrodes, the molten pool formed by the transferred ion arc will deviate from the surface to be processed, resulting in poor spraying quality of the three-electrode plasma spraying device. Summary of the invention

[0004] The object of the present invention is to provide a three-electrode plasma spraying device, comprising a manipulator, a spray gun and a wave-shaped undulating base surface, wherein the manipulator is used to drive the spray gun and control the distance and verticality between the spray gun and the wave-shaped undulating base surface, the spray gun is provided with a nozzle anode and a tungsten rod cathode, the tungsten rod cathode is axially installed in the center of the nozzle anode, a channel for generating a non-transferred ion arc is reserved between the tungsten rod cathode and the nozzle anode, the wave-shaped undulating base surface is a workpiece anode, a transferred ion arc is generated between the tungsten rod cathode and the wave-shaped undulating base surface, and an axial driving mechanism for adjusting the distance from the wave-shaped undulating base surface is provided on the tungsten rod cathode.

[0005] Preferably, the axial driving mechanism comprises an electric lifting frame and an insulating sleeve, the electric lifting frame is fixed on the spray gun, and the moving end of the electric lifting frame is fixedly connected to the tungsten rod cathode through the insulating sleeve.

[0006] Preferably, an insulating sleeve is provided in the spray gun, and the insulating sleeve is sleeved on the outside of the tungsten rod cathode, a moving part exposing the insulating sleeve is left at the top of the tungsten rod cathode, and a conductive part exposing the insulating sleeve is left at the bottom of the tungsten rod cathode.

[0007] Preferably, the tungsten rod cathode and the nozzle anode are connected to a first power supply.

[0008] Preferably, the tungsten rod cathode and the workpiece anode are connected to a second power supply.

[0009] The advantages and beneficial effects of the present invention are: providing a three-electrode plasma spraying device, which can be suitable for workpieces with wavy base surfaces, especially when spraying in the trough section, the position of the tungsten rod cathode can be axially adjusted so that the distance from the tungsten rod cathode to the surface to be processed is maintained at a minimum distance relative to the distance to other surfaces, thereby causing a molten pool formed by a transferred ion arc to be generated at the surface to be processed, thereby making the coating dense and having strong adhesion, thereby improving the spraying quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the present invention.

[0011] Figure 2 It is a schematic diagram of adjusting the tungsten rod cathode of the present invention. DETAILED DESCRIPTION

[0012] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0013] The technical solution specifically implemented in the present invention is: like Figure 1 and Figure 2 As shown, a three-electrode plasma spraying device includes a manipulator (not shown in the figure), a spray gun 1 and a wavy base surface 2, the manipulator is used to drive the spray gun 1 and control the distance and verticality between the spray gun 1 and the wavy base surface 2, the spray gun 1 is provided with a nozzle anode 3 and a tungsten rod cathode 4, the tungsten rod cathode 4 is axially installed in the center of the nozzle anode 3, a channel for generating a non-transferred ion arc is reserved between the tungsten rod cathode 4 and the nozzle anode 3, the wavy base surface 2 is a workpiece anode, a transferred ion arc is generated between the tungsten rod cathode 4 and the wavy base surface 2, and an axial driving mechanism 5 for adjusting the distance from the wavy base surface 2 is provided on the tungsten rod cathode 4.

[0014] The above-mentioned axial driving mechanism 5 includes an electric lifting frame 51 and an insulating sleeve 52. The electric lifting frame 51 is fixed on the spray gun 1, and the moving end of the electric lifting frame 51 is fixedly connected to the tungsten rod cathode 4 through the insulating sleeve 52; specifically, the tungsten rod cathode 4 is driven to move axially by the electric lifting frame 51, so as to adjust the position of the tungsten rod cathode 4, so that the distance from the tungsten rod cathode 4 to the surface to be processed on the wavy base surface 2 is maintained at a minimum distance relative to the distance to other surfaces.

[0015] An insulating sleeve 6 is provided in the spray gun 1, and the insulating sleeve 6 is sleeved on the outside of the tungsten rod cathode 4. A moving portion exposing the insulating sleeve 6 is left at the top of the tungsten rod cathode 4, and a conductive portion exposing the insulating sleeve 6 is left at the bottom of the tungsten rod cathode 4. Specifically, the tungsten rod cathode 4 is radially fixed by the insulating sleeve 6 to avoid displacement of the tungsten rod cathode 4 during axial movement, and to prevent the non-transferred ion arc between the tungsten rod cathode 4 and the nozzle anode 3 from affecting the melting powder due to the change in spacing. At the same time, the insulating sleeve 6 is matched with the insulating sleeve 52 to have a radial limiting function to prevent the tungsten rod cathode 4 from axially extending beyond the powder spraying distance of the spray gun 1.

[0016] The tungsten rod cathode 4 and the nozzle anode 3 are connected to a first power supply 7 ; specifically, a non-transferred ion arc is generated between the nozzle anode 3 and the tungsten rod cathode 4 through the first power supply 7 .

[0017] The tungsten rod cathode 4 and the workpiece anode are connected to a second power supply 8 ; specifically, a transferred ion arc is generated between the workpiece anode and the tungsten rod cathode 4 through the second power supply 8 .

[0018] When in use, the manipulator controls the spray gun 1 to move on the wavy base surface 2, so that the spacing and verticality between the spray gun 1 and the wavy base surface 1 are always consistent. When the spray gun 1 moves to the trough section 21, the manipulator controls the spray gun 1 to penetrate into the trough section 21, so that the spacing between the nozzle anode 3 of the spray gun 1 and the surface to be processed on the wavy base surface 2 remains unchanged (that is, the spraying distance remains unchanged). At the same time, the moving end of the electric lifting frame 51 drives the tungsten rod cathode 4 to move along the axial direction of the spray gun 1 through the insulating sleeve 52, so that the tungsten rod cathode 4 approaches the surface to be processed, so that the distance between the tungsten rod cathode 4 and the surface to be processed is maintained at the minimum spacing relative to the distance to other surfaces, thereby causing the molten pool formed by the transferred ion arc to be generated at the surface to be processed, and the molten material sprayed from the spray gun 1 is combined with the molten pool of the surface to be processed to complete the spraying, so that the coating is dense and has strong adhesion, thereby improving the spraying quality.

[0019] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A three-electrode plasma spraying device, comprising a manipulator, a spray gun and a wavy base surface, wherein the manipulator is used to drive the spray gun and control the distance and verticality between the spray gun and the wavy base surface, characterized in that: The spray gun is provided with a nozzle anode and a tungsten rod cathode. The tungsten rod cathode is axially installed inside the center of the nozzle anode. A channel for generating a non-transferred ion arc is reserved between the tungsten rod cathode and the nozzle anode. The undulating base surface is the workpiece anode. A transferred ion arc is generated between the tungsten rod cathode and the undulating base surface. An axial driving mechanism for adjusting the distance between the tungsten rod cathode and the undulating base surface is provided on the tungsten rod cathode.

2. A three-electrode plasma spraying device according to claim 1, characterized in that: The axial driving mechanism comprises an electric lifting frame and an insulating sleeve. The electric lifting frame is fixed on the spray gun, and the moving end of the electric lifting frame is fixedly connected to the tungsten rod cathode through the insulating sleeve.

3. A three-electrode plasma spraying device according to claim 2, characterized in that: An insulating sleeve is arranged in the spray gun, and the insulating sleeve is sleeved on the outside of the tungsten rod cathode. A moving part exposing the insulating sleeve is left at the top of the tungsten rod cathode, and a conductive part exposing the insulating sleeve is left at the bottom of the tungsten rod cathode.

4. A three-electrode plasma spraying device according to claim 3, characterized in that: The tungsten rod cathode and the nozzle anode are connected to a first power supply.

5. A three-electrode plasma spraying device according to claim 4, characterized in that: The tungsten rod cathode and the workpiece anode are connected to a second power supply.

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