Plasma spray gun applying high-ignition-point graphite boat coating

Abstract

The plasma spray gun applying the high-ignition-point graphite boat coating comprises a nozzle, a powder inlet hole is formed in the side wall of the nozzle, the nozzle is sleeved with a powder feeding frame, the powder feeding frame is provided with a through hole corresponding to the powder inlet hole, the powder feeding frame is connected with a powder feeding needle sleeve, and a needle tube of the powder feeding needle sleeve penetrates through the through hole of the powder feeding frame and is inserted into the powder inlet hole of the nozzle. According to the internal powder feeding device, zirconium oxide powder enters flames in advance through the internal powder feeding design, compared with an external powder feeding mode, powder melting is good, meanwhile, airflow of the internal powder feeding device forms rotating airflow, it is guaranteed that powder materials are more concentrated to form a compact coating, and therefore the powdering rate is better improved.

Description

TECHNICAL FIELD

[0001] The utility model discloses a kind of plasma torches of high ignition point graphite boat coating application, and it belongs to plasma torch technical field according to international patent classification (IPC). BACKGROUND

[0002] Hard alloy industry is configured graphite boat when sintering, and zirconium oxide layer is sprayed on the surface of graphite boat by plasma spraying equipment, so that high-temperature resistance and sintering quality can be improved.Currently, powder feeding of the spray gun generally adopts an external powder feeding mode, i.e., the powder feeding port is outside the nozzle of the spray gun, and the powder melting is not good, and the powder feeding rate is low. SUMMARY

[0003] In view of the deficiencies of the prior art, the utility model provides a kind of plasma torches of high ignition point graphite boat coating application, and the powder feeding structure is extended, the powder melting is good, and the powder feeding rate is improved.

[0004] To achieve the above object, the utility model is realized by the following technical scheme:

[0005] A kind of plasma torches of high ignition point graphite boat coating application, including nozzle, the side wall of nozzle is equipped with powder inlet hole, nozzle is sleeved with powder feeding frame, powder feeding frame is equipped with the through hole corresponding with powder inlet hole, powder feeding frame is connected with powder feeding needle sleeve, the needle tube of powder feeding needle sleeve is inserted into the powder inlet hole of nozzle through the through hole of powder feeding frame.

[0006] Further, the nozzle has an inner cavity and a nozzle channel connected thereto, and the central axis of the nozzle powder inlet hole is perpendicular to the central axis of the nozzle channel.

[0007] Further, the powder feeding frame is provided with symmetrical protrusions sleeved on the outer periphery of the nozzle, and the protrusions are provided with through holes in the radial direction to cooperate with the needle tube of the powder feeding needle sleeve.

[0008] Further, the nozzle is connected to the gun body of the spray gun, and the gun body of the spray gun includes a mandrel and a spray gun main body arranged outside the mandrel.

[0009] Further, the gas inlet holes of the distribution valve are symmetrically arranged as inclined holes, the outer ends of the gas inlet holes are connected to the front-end gas chamber, the inner side walls of the gas inlet holes are connected to the inner cavity where the electrode is located, and the symmetrically arranged gas inlet holes form a vortex gas flow which passes through the nozzle under the action of the electric arc to form a plasma torch.

[0010] Further, the extension direction of the gas inlet holes of the distribution valve is perpendicular to the extension direction of the central axis of the electrode.

[0011] Furthermore, the spray gun body includes an outer body and a matching middle sleeve. The rear end of the outer body is provided with an air inlet, which extends forward and towards the center to the first air chamber between the outer body and the middle sleeve. The first air chamber is an annular air chamber. The annular air chamber is connected to the second air chamber between the middle sleeve and the mandrel through a circumferential oblique air passage on the middle sleeve. The second air chamber is connected to the front air chamber through an oblique air passage on the middle sleeve. The outer side of the front air chamber is the outer body, and the inner side of the front air chamber is the middle sleeve. The distribution valve is part of the middle sleeve. The air inlet, the first air chamber, the second air chamber, and the front air chamber of the spray gun body form an air intake channel through the air inlet hole of the distribution valve.

[0012] Furthermore, the mandrel extends from the rear end opening to the front end to form a cooling channel, the front end of the mandrel is sealed to form an electrode, and the mandrel sidewall is provided with a mandrel hole. The coolant passes through the mandrel hole and through the intermediate sleeve and the outer body to enter the annular outer cavity of the nozzle for cooling, and finally is discharged outward through the return channel provided in the outer body.

[0013] This invention, through its internal powder feeding design, allows zirconia powder to enter the flame earlier. Compared with the external powder feeding mode, this increases the distance the powder travels in the flame, resulting in better powder melting and making it more conducive to powder spraying. This can increase the zirconia powder application rate by more than 10%.

[0014] The nozzle of this invention is matched with the electrode. The working gas, such as argon, enters the nozzle through the rear end of the spray gun body. The distribution valve makes the airflow form a rotating airflow. After the powder material, such as zirconium oxide, enters the arc flame, it is propelled forward in a spiral manner, so that the powder material is more concentrated and sprayed and bonded to the surface of the workpiece, thereby forming a dense coating. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an embodiment of the present utility model.

[0016] Figure 2 This is a cross-sectional view of the powder feeding needle sleeve in an embodiment of this utility model.

[0017] Figure 3 This is a first cross-sectional view of the air intake channel according to an embodiment of the present invention.

[0018] Figure 4 This is a second cross-sectional view of the air intake channel according to an embodiment of the present invention.

[0019] Figure 5 This is a third sectional view of the air intake channel according to an embodiment of this utility model.

[0020] Figure 6 This is a radial sectional view of the intake air passage distribution valve according to an embodiment of this utility model.

[0021] Figure 7 This is a cross-sectional view of the cooling channel in an embodiment of this utility model.

[0022] Figure 8 is another angle view of the cooling runner profile of the embodiment of the utility model. DETAILED DESCRIPTION

[0023] The utility model will be further described in connection with the drawings:

[0024] Embodiment: please see Figures 1 to 8 , a kind of application high ignition point graphite boat coating's plasma torch, including nozzle 1, powder inlet hole 11 is equipped in the side wall of nozzle 1, nozzle 1 is sleeved with powder feeding frame 2, powder feeding frame 2 is equipped with the through hole corresponding with powder inlet hole, powder feeding frame 2 is connected with powder feeding needle sleeve 3, the needle tube 31 of powder feeding needle sleeve 3 is inserted into the powder inlet hole 11 of nozzle 1 by passing the through hole of powder feeding frame 2.The nozzle 1 of the utility model is connected in the front end of torch by screw thread, nozzle 1 has inner cavity and the nozzle hole channel 12 connected, the central axis of nozzle powder inlet hole 11 is perpendicular to the central axis of nozzle hole channel 12.The utility model torch adopts internal straight powder feeding mode, water circulation is carried out in electrode head, service life will be long, and spraying effect is good.In an embodiment of the utility model, symmetric protrusion 21 is equipped on powder feeding frame 2 and is sleeved in the outer periphery of nozzle 1, and the through hole is radially equipped in protrusion and cooperates with the needle tube of powder feeding needle sleeve 3.

[0025] please see Figures 1 to 8 , in an embodiment of the utility model, nozzle 1 is connected with torch barrel 4, and torch barrel 4 includes mandrel 5 and the torch main body arranged outside mandrel, and cooling channel is arranged in mandrel 5, and electrode 51 is formed at the front end of mandrel 5, and the side wall of nozzle 1 has spacing with the front end electrode 51 of mandrel 5, and gas inlet channel 7 is arranged on the torch main body, and gas inlet channel extends to distribution valve 6 at the front end of torch main body, and the side wall of distribution valve is circumferentially provided with gas inlet hole 61, and gas enters the chamber between electrode 51 and nozzle 1 to form rotating gas flow or vortex gas flow.The gas inlet hole 61 of distribution valve 6 is symmetrically arranged as inclined hole, and the outer end of each gas inlet hole is connected with front end gas chamber 701, and the inner side wall of gas inlet hole is connected with the inner cavity where electrode is arranged, and vortex gas flow is formed by symmetric gas inlet hole, and under the action of arc, plasma torch is formed by nozzle.The extension direction of gas inlet hole of distribution valve 6 is perpendicular to the extension direction of electrode central axis.In an embodiment of the utility model, the torch main body includes outer main body 8 and the middle layer sleeve 9 matched with each other, and the rear end of outer main body 8 is provided with gas inlet, and the gas inlet extends to the first gas chamber 702 between outer main body and middle layer sleeve towards center, as shown in the figure, Figure 4As shown, the first air chamber 702 is an annular air chamber arranged on the outer periphery of the intermediate sleeve 92, which is communicated to the second air chamber 704 between the middle sleeve and the mandrel through the oblique downward circumferential air passage 703 on the intermediate sleeve of the middle sleeve sleeve, and the second air chamber is located between the intermediate sleeve, the front sleeve and the mandrel, and the second air chamber is communicated to the front end air chamber 705 through the oblique air passage 705 of the front sleeve of the middle sleeve sleeve, and the front end air chamber 705 is outside the outer main body, and the front end air chamber is inside the middle sleeve (specifically the front sleeve) and the front end distribution valve 6, and the gas inlet of the spray gun body, the first air chamber 702, the second air chamber 704, the front end air chamber 701 and the connecting channel form the gas inlet flow channel through the gas inlet hole of the distribution valve.

[0026] In an embodiment of the utility model, please refer to Figure 7 And Figure 8 The rear end of the spray gun mandrel 5 is opened to the front end to form a cooling hole, the front end of the mandrel 5 is blocked to form an electrode 51, the side wall of the mandrel is provided with a mandrel hole 52, the cooling liquid passes through the mandrel hole 52 and passes through the front sleeve 91 of the intermediate sleeve to the corrugated water channel 801 of the front main body 81 of the outer main body 8 and enters the annular outer cavity 100 of the nozzle to be cooled, finally passes through the backflow water channel 802 arranged on the front main body 81 of the outer main body 8, and the water outlet of the backflow water channel 802 enters the water chamber 803, the water chamber is located in the sealing cavity between the combination of the front main body 81 and the rear main body 82 and the middle sleeve, and the cooling liquid of the water chamber is discharged outward through the backflow channel of the rear main body 82.

[0027] In an embodiment of the utility model, the outer main body of the spray gun can include the front main body 81 and the matched rear main body 82 connected in sequence, and the middle sleeve includes the front sleeve 91, the matched intermediate sleeve 92 and the rear sleeve 93 connected in sequence. The rear end of the spray gun is provided with a water inlet 101, a water outlet 102 and an air inlet 103, the water inlet and the water outlet form a spray gun cooling flow channel, and the air inlet extends inward to form an air inlet flow channel.

[0028] The utility model discloses through inside powder feeding design, make zirconia powder advance into flame, compared with outside powder feeding mode, lengthen the distance of powder in flame, make powder melt better, more favorable to powder spraying, can improve zirconia powder rate by 10% or more. The utility model discloses that the nozzle cooperates with the electrode, and the high voltage between the two forms arc working gas (such as argon or / and hydrogen mixed gas), which enters the nozzle through the rear end of the spray gun body, is heated and ionized when meeting high-temperature arc, generates plasma arc, and the distribution valve makes the airflow form rotating airflow, and the powder material such as zirconia enters the arc flame and is pushed forward in a spiral way, so that the powder material is more concentrated and combined with the workpiece surface, thereby forming a dense coating. At the same time, the powder material adopts the inside powder feeding mode, and the structure is further improved to improve the powder rate.

[0029] The above-described embodiments are merely illustrative for the application and any modification, change, or improvement made by any person skilled in the art with the application shall fall within the scope of the patent claimed by the application, and are not limited to the embodiments disclosed.

Claims

1. A plasma spray gun with a high ignition point graphite boat coating, characterized in that: Includes a nozzle, the side wall of which is provided with a powder inlet hole, a powder feeding frame is connected to the nozzle sleeve, the powder feeding frame is provided with a through hole corresponding to the powder inlet hole, the powder feeding frame is connected to a powder feeding needle sleeve, and the needle tube of the powder feeding needle sleeve passes through the through hole of the powder feeding frame and is inserted into the powder inlet hole of the nozzle. The nozzle is connected to the spray gun body, which includes a spindle and a spray gun body disposed outside the spindle. The spindle has cooling channels inside, and an electrode is formed at the front end of the spindle. The electrode at the front end of the spindle is spaced from the side wall of the nozzle. The spray gun body has an air inlet channel that extends to a distribution valve at the front end of the spray gun body. The side wall of the distribution valve has an air inlet hole along the circumference. Gas enters the chamber between the electrode and the nozzle to form a rotating airflow.

2. A plasma spray gun with a high ignition point graphite boat coating according to claim 1, characterized in that: The nozzle has an inner cavity and a connected nozzle channel, and the central axis of the nozzle powder inlet is perpendicular to the central axis of the nozzle channel.

3. A plasma spray gun with a high ignition point graphite boat coating according to claim 1, characterized in that: The powder feeding frame has symmetrical protrusions that fit around the outer periphery of the nozzle, and the protrusions have through holes in the radial direction that cooperate with the needle tube of the powder feeding needle sleeve.

4. A plasma spray gun with a high ignition point graphite boat coating according to claim 1, characterized in that: The distribution valve has symmetrically arranged oblique holes for air inlets. The outer end of each air inlet is connected to the front air chamber, and the inner wall of the air inlet is connected to the inner cavity where the electrode is located. The symmetrical air inlets form a vortex airflow that, under the action of the electric arc, passes through the nozzle to form a plasma torch.

5. A plasma spray gun with a high ignition point graphite boat coating according to claim 1, characterized in that: The direction of the air inlet of the distribution valve is perpendicular to the direction of the electrode's central axis.

6. A plasma spray gun with a high ignition point graphite boat coating according to any one of claims 1 to 5, characterized in that: The spray gun body includes an outer body and a matching middle sleeve. The rear end of the outer body has an air inlet. The air inlet extends forward and towards the center to the first air chamber between the outer body and the middle sleeve. The first air chamber is an annular air chamber. The annular air chamber is connected to the second air chamber between the middle sleeve and the mandrel through a circumferential oblique air passage on the middle sleeve. The second air chamber is connected to the front air chamber through an oblique air passage on the middle sleeve. The outer body is outside the front air chamber, and the middle sleeve is inside the front air chamber. The distribution valve is part of the middle sleeve. The air inlet, the first air chamber, the second air chamber, and the front air chamber of the spray gun body form an air intake channel through the air inlet hole of the distribution valve.

7. A plasma spray gun with a high ignition point graphite boat coating according to claim 1, 2, 3, 4, or 5, characterized in that: The mandrel extends from the rear end opening to the front end to form a cooling channel. The front end of the mandrel is sealed to form an electrode. The mandrel sidewall is provided with a mandrel hole. The coolant passes through the mandrel hole and through the intermediate sleeve and the outer body to enter the annular outer cavity of the nozzle for cooling. Finally, it is discharged outward through the return channel provided in the outer body.

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