JPH05179417A - Plasma thermal spraying device - Google Patents

Abstract

PURPOSE:To improve the operating rate of equipment and to prevent the degradation in the quality of the thermally sprayed film of a work by arranging a device for cleaning a thermal spraying gun nozzle within a treating chamber of the plasma thermal spraying device cleaning of the nozzle. CONSTITUTION:After the inside of a treating vessel 1 having the thermal spraying gun 7 is evacuated to a vacuum, an inert gas is introduced therein and a door 3 is opened. The work 6 in an auxiliary vessel 2 is then inserted by a transporting device 5 into the treating vessel 1 and is set in the position opposite to the nozzle 8 of the thermal spraying gun 7. Thermal spraying powder is plasma thermally sprayed to the surface of the work 6 from a feed port 9 and thereafter, the transporting device 5 is retreated and the thermally sprayed work 6 is returned into the auxiliary vessel 3. The door 3 is then closed. The nozzle cleaning device 12 mounted to the front end of the rod 13 in the treating vessel 1 is advanced to the position right under the thermal spraying gun 7 and the unmolten powder for thermal spraying in the nozzle 8 is removed and cleaned by rotating a brush 11 in order to prevent the dropping and sticking of the unmolten powder for thermal spraying sticking to the inside surface of the nozzle 8 of the thermal spraying gun 7 onto the surface of the work at the time of the next thermal spraying and the consequent deterioration of the quality of the thermally sprayed quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention sends a powder of metal, ceramics or the like into a plasma arc in a container set in an atmosphere isolated from the atmosphere to form a thermal spray coating on the surface of a material to be sprayed. More particularly, the present invention relates to a nozzle spray cleaning system for a spray gun in a plasma spray apparatus for forming a spray coating on the surface of a turbine blade of a jet engine or a gas turbine.

[0002]

2. Description of the Related Art In a plasma spraying apparatus as shown in FIG. 5 in which a sprayed material is plasma sprayed onto a sprayed object by a plasma spraying gun in a processing container, steps 51 to 62 in the flow chart of FIG. 6 are shown. Thermal spraying is performed in such an order. That is, first, the inside of the processing container 1 is evacuated, and then an inert gas is filled therein to set a thermal spray atmosphere. And the processing container 1
Open the door 3 of the sub container 2 adjacent to the guide rail 15
The object 6 to be sprayed is mounted in the sub-container 2 at the tip of the carrier device 5 guided by the above. Next, the vacuum pump 1 is passed through the sub-container 2 through the pipe 16, the filter 17, and the butterfly valve 19.
After vacuuming with 8, an inert gas is enclosed and a thermal spray atmosphere is set. After that, the sluice valve 4 is opened, and the conveying device 5 is driven through the ball screw 14 by a driving device (not shown).
Is driven to convey the material 6 to be sprayed into the processing container 1. When the sprayed material 6 is conveyed to a position where the sprayed material 6 and the nozzle 8 of the spray gun 7 face each other, the powder 2 which is the spraying material from the feeding port 9
1 is supplied to actually perform thermal spraying. And after the spraying is finished,
The object 6 to be sprayed is conveyed from the processing container 1 to the sub container 2, the sluice valve 4 is closed, the sub container 2 is opened to the atmosphere, and the door 3 is opened to take out the object 6 to be sprayed.

When the above-mentioned thermal spraying is carried out for a long time, the powder 21 may adhere to the inner surface of the nozzle 8 of the thermal spray gun 7 in an unmelted state as shown in FIG. If the unmelted powder 21 falls onto the surface of the object 6 to be sprayed before or during thermal spraying and accumulates, the unmelted powder 21 remains unmelted because the heat input by the plasma is insufficient. Form a sprayed coating. Therefore, the local quality of the sprayed coating deteriorates, and mechanical properties such as strength, toughness and hardness of the sprayed coating deteriorate. Therefore, it is necessary to clean the inner surface of the nozzle 8 of the thermal spray gun 7.

Conventionally, in order to clean the inner surface of the nozzle 8 of the thermal spray gun 7, as shown in steps 63 to 68 of FIG. 6, after the cleaning time is determined, the processing container 1 is first set to the thermal spray atmosphere. The inside is brought to atmospheric pressure, the maintenance door 20 is opened, and the spray gun 7 is attached to the maintenance door 20.
To remove the unmelted powder 21 adhering to the inner surface of the nozzle of the spray gun 7 with a brush or blow it off with gas or the like, and then close the maintenance door 20 to close the inside of the processing container 1 with the pipe 16 and the filter. 17 and butterfly valve 1
The vacuum pump 18 was used to evacuate the vacuum, and after the evacuation to the predetermined pressure was completed, an inert gas was enclosed and the thermal spray atmosphere was set again.

[0005]

However, when cleaning the inner surface of the nozzle of the thermal spray gun after opening the maintenance door after setting the atmospheric pressure in the processing container set to the thermal spraying atmosphere, once the internal space of the processing container is To open to the atmosphere,
Since water vapor contained in the atmosphere adheres to the inner wall of the processing container, it takes a long time to set the thermal spray atmosphere again. Therefore, there is an increasing demand for improvement of the nozzle cleaning method of the thermal spray gun from the viewpoint of reducing the downtime of the equipment as much as possible, improving the productivity, increasing the production amount per unit time, and reducing the processing cost.

In view of the above-mentioned problems of the prior art, the main object of the present invention is to reduce the downtime of the equipment, improve the productivity, and further increase the production amount per unit time, and process it. An object of the present invention is to provide a low cost plasma spraying apparatus.

[0007]

According to the present invention, there is provided a plasma spraying apparatus for plasma spraying a sprayed material toward a sprayed object with a plasma spray gun in the processing container according to the present invention. A plasma spraying device, characterized in that it has a cleaning device for the nozzle of the spraying gun that is movable between a position for cleaning the spraying gun and a position for not cleaning, Cleaning the inner surface of the nozzle of the plasma spray gun in a plasma spray apparatus that plasma sprays the spray material with a plasma spray gun in the processing container toward a removable spray object in a sub container adjacent to the container A cleaning device for removing the plasma spray gun is selectively attached to the transfer device, and the cleaning device is attached to the transfer device instead of the object to be sprayed. It is accomplished by providing a spray coating apparatus, characterized in that the nozzle inner surface was cleanable.

[0008]

According to the above structure, the inner surface of the nozzle of the thermal spray gun is cleaned by the same procedure as that of performing the thermal spraying once by using the time for exchanging the thermal sprayed object or by using the carrier for the thermal sprayed object. Can be cleaned.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a plasma spraying apparatus in which a nozzle cleaning device 10 for a spraying gun 7 is provided in a processing container will be described below with reference to FIGS.

The plasma spraying apparatus of this embodiment (FIG. 1) has a structure similar to that of the conventional apparatus shown in FIG. 5, but the nozzle cleaning device 10 held at the tip of the rod 13 is disposed inside the processing container 1. It is located in. The rod 13 is guided by a guide rail 15 and driven by a ball screw 14 by a driving device (not shown). That is, the position where the center of the nozzle 8 in the center of the processing container 1 and the center of the cleaning brush 11 driven by the drive unit 12 including the motor and the speed reducer of the nozzle cleaning device 10 coincide with each other and the thermal spraying in the processing container 1. Nozzle cleaning device 1 between a position that does not affect work (for example, the right side in FIG. 1)
0 is selectively transported.

Next, the operating procedure of this embodiment will be described with reference to the flowchart of FIG. First, after the thermal spraying treatment similar to the conventional method is performed on the thermal spraying target 6 in the processing container 1 (step 1 to step 5, step 7 to step 9), the thermal spraying target 6 is transferred to the sub-container 2 by the transfer device 5. (Step 8), close the sluice valve 4 (step 11),
The inside of the sub-container 2 is opened to the atmosphere, the door 3 is opened, and the object 6 to be sprayed which has been subjected to the plasma spraying is taken out (step 12,
13). Then, the process returns to step 3 and the subsequent steps are repeated.

On the other hand, at the same time as the work in the sub-container 2 in steps 3 to 5 described above, the rod 13 holding the nozzle cleaning device 10 is advanced toward the center of the processing container 1, and the brush 11 is located just below the center of the nozzle 8. Is stopped at a position where the centers of the nozzles coincide with each other, then the spray gun 7 is hung down, and the brush 11 is brought into contact with and rotated by the inner surface of the nozzle 8 to clean the inner surface of the nozzle 8 (step 6). After cleaning the inner surface of the nozzle 8, the rotation of the brush 11 is stopped, the spray gun 7 is lifted to return it to a predetermined position, and the rod 13 is retracted.
To the processing container 1 by opening the sluice valve 4
And advance plasma spraying.

By cleaning the inner surface of the nozzle 8 of the thermal spray gun 7 by this method, the downtime of the equipment due to the cleaning of the inner surface of the nozzle 8 can be eliminated.

Next, a second embodiment in which the nozzle cleaning method of the thermal spray gun 7 can be improved by using the transport device 5 for the thermal sprayed material 6 will be described with reference to FIGS. 3 and 4.

The structure of the plasma spraying apparatus in this embodiment is almost the same as that of the conventional plasma spraying apparatus, but the nozzle cleaning device 10 can be held at the tip of the transfer device 5.

Next, the operation procedure of this embodiment will be described with reference to the flow chart of the drawing. Thermal spray object 6 of this embodiment
Since the thermal spraying process for is similar to that of the first embodiment, its description is omitted (steps 21 to 32).

After the thermal spraying process on the thermal spraying target 6 is completed and the thermal spraying target 6 is taken out, when it is judged in Step 33 that the nozzle cleaning time has come, the processing container 1 is operated in Step 34.
The inside of the sub-container 2 is set to atmospheric pressure in the plasma spraying atmosphere, the door 3 is opened, the transfer device 5 is operated to set it at a predetermined position, and the nozzle cleaning device 10 is held by the transfer device 5, and then the door 3 is opened. Close it. Next, the inside of the sub-container 2 is evacuated (step 35), and after the evacuation to a predetermined pressure is completed, an inert gas is filled to create the same atmosphere as the inside of the processing container 1 (step 36). After opening (step 37), the carrier device 5 holding the nozzle cleaning device 10 is advanced toward the center of the processing container 1 and stopped at a position where the center of the brush 11 is directly below the center of the nozzle 8 (step 38). afterwards,
The spray gun 7 is hung down, and the brush 11 is brought into contact with and rotated on the inner surface of the nozzle 8 to clean the inner surface of the nozzle 8 (step 3).
9). After cleaning the inner surface of the nozzle 8, the rotation of the brush 11 is stopped, the spray gun 7 is lifted and returned to a predetermined position, and the carrier device 5 is retracted in the direction of the sub container 2 and set to a predetermined position. From (step 40), the sluice valve 4 is closed (step 41) to maintain the thermal spray atmosphere in the processing container 1. Next, the sub-container 2 is brought to atmospheric pressure, the door 3 is opened (step 42), and the nozzle cleaning device 10 is removed (step 4).
3). After this, the process returns to step 23, the object to be sprayed 6 is held by the carrier device 5, and the spraying work is started again.

By this method, the inner surface of the nozzle 8 of the thermal spray gun 7 can be cleaned while the inside of the processing container 1 is maintained in the atmosphere of plasma spraying, and the equipment down time due to the cleaning of the inner surface of the nozzle 8 is one. The time required for the thermal spraying of the object 6 to be sprayed can be the same, and the conventional spray gun 7 can be used.
As compared with the nozzle cleaning method described in (1), the time required for opening the atmosphere in the processing container 1, evacuation, and filling with an inert gas can be shortened.

[0019]

With the above construction, in the plasma spraying apparatus, it is possible to secure the quality of the sprayed coating, improve the productivity of the equipment and increase the productivity per unit time, and reduce the processing cost. it can.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operating procedure of the first embodiment.

FIG. 3 is a side sectional view showing a second embodiment of the present invention.

FIG. 4 is a flowchart showing the operating procedure of the second embodiment.

FIG. 5 is a side sectional view showing a conventional plasma spray apparatus.

FIG. 6 is a flow chart showing an operating procedure of a conventional plasma spraying apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing container 2 Sub-container 3 Door 4 Gate valve 5 Transfer device 6 Thermal spray material 7 Thermal spray gun 8 Nozzle 9 Powder feeding port 10 Nozzle cleaning device 11 Brush 12 Drive unit 13 Rod 14 Ball screw 15 Rail 16 Vacuum piping 17 Filter 18 Vacuum Pump 19 Butterfly Valve 20 Maintenance Door 21 Unmelted Powder

Claims (2)

[Claims] 1. A plasma spraying apparatus for plasma spraying a sprayed material toward an object to be sprayed by a plasma spraying gun in the processing container, wherein a position for cleaning the spray gun in the processing container and a position for not cleaning the spray gun. A plasma spraying device comprising a cleaning device for a nozzle of the spray gun movable between the two. 2. A plasma capable of being plasma-sprayed with a plasma spray gun in the processing container toward a sprayed object that can be carried by a carrying device and is removable in a sub-container adjacent to the processing container. In the thermal spraying device, a cleaning device for cleaning the inner surface of the nozzle of the plasma spray gun can be attached to and detached from the carrying device, and the cleaning device is selectively attached to the carrying device instead of the object to be sprayed. A plasma spray apparatus, wherein the inner surface of the nozzle of the plasma spray gun can be cleaned.