JP2505911Y2 - Plasma spraying equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a plasma spray apparatus, and more particularly to a plasma spray apparatus capable of reducing the amount of raw materials used.

[Prior Art] Conventionally, as a plasma spraying apparatus, for example, one shown in FIG. 3 has been known.

Such a plasma spraying apparatus causes a discharge between electrodes by a high voltage given by a high frequency generator 10, and a spraying gun 20 which generates a plasma flame of about 30,000 degrees under the supply of nitrogen gas, helium gas, or the like. And this spray gun 20
A thermal spray powder supply device 30 for supplying thermal spray powder is provided. Then, the thermal spraying powder such as magnesium oxide is supplied from the thermal spraying powder supply device 30 to a supply line of a carrier gas such as argon gas, and is guided to the nozzle tip portion of the thermal spray gun 20.

Thus, when using such a plasma spraying apparatus to continuously perform thermal spraying processing on a product, in order to avoid wasteful consumption of the thermal spraying powder at the time of loading and unloading the product, the thermal spraying powder supply device 30 is used. There is a so-called intermittent operation that is temporarily stopped.

[Problems to be Solved by the Invention] However, in such a conventional plasma spraying apparatus, the spraying powder supply device 30 and the spraying gun 20 cannot be provided so close to each other because of their structures, The supply pipeline for supplying the thermal spray powder has to be set to a certain length.

As a result, when the spraying powder supply device 30 is stopped by the intermittent operation, and when the operation is restarted, it takes a considerable time until the spraying powder is stably supplied, and the weight of the sprayed coating on the product varies. Becomes Therefore, the time during which the supply of the thermal spray powder can be stopped is limited to an extremely short time, and there is a problem that the substantial effect of reducing the amount of the thermal spray powder used cannot be obtained.

An object of the present invention is to provide a plasma spraying apparatus which can solve the above conventional problems and prevent wasteful use of the sprayed powder without causing variations in the weight of the sprayed coating on products.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention forms a return pipe in a pipe for supplying a thermal spray powder together with a carrier gas to a thermal spray gun, and forms a return pipe in both branches. It is characterized in that the pipeline is provided with selective blocking means for selectively blocking the communication between the two pipelines.

[Operation] According to the present invention, when the supply line side of the selective blocking means provided in the middle of both pipelines downstream of the branch portion is shut off,
The supply of the thermal spray powder to the thermal spray gun is stopped, and the thermal spray powder supplied from the thermal spray powder supply device is guided to the return conduit.
Then, when the selective shutoff means is switched from this state to shut off the return conduit side, the return operation is stopped and the supply of the sprayed powder to the spray gun is restarted. The selective shutoff means can be provided close to the spray gun, and since the spray powder supply device can be operated continuously, the supply of the spray powder is always stable, It is possible to perform plasma spraying processing without waste and variation.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

 1 and 2 show one embodiment of the present invention.

In the figure, the plasma spraying apparatus has a high-frequency generator 10, a supply line 21 for supplying nitrogen gas and helium gas, as in the conventional case.
And 22, and a spray gun 20 to which a cooling water supply pipe 23 is connected, and a spray powder supply device 30 for supplying a spray powder to the spray gun 20. Then, the thermal spraying powder such as magnesium oxide is supplied from the thermal spraying powder supply device 30 to the supply pipeline 31 of the carrier gas such as argon gas, and is guided to the nozzle tip portion of the thermal spray gun 20.

Reference numeral 40 denotes a selective shutoff device provided near the thermal spray gun 20 in the supply pipeline 31, and as shown in detail in FIG. 2, is formed with the supply pipeline 31 and a branch to the supply pipeline 31. In the middle of the return pipe 32, an elastic pipe 41 made of a soft rubber material or the like is provided as selective shut-off means,
42, a rod member 43 provided between these elastic body pipes 41 and 42 and capable of press-contacting either one of them, and this rod member
An operation mechanism (not shown) for switching 43 is provided.
In order to facilitate this switching operation, the supply pipe line 31 and the return pipe line 32 downstream of the branch portion and the elastic body pipes 41 and 42 are arranged in parallel. The return line 32 is further connected to a collection container 50 for sprayed powder.

In the present embodiment having the above-described configuration, as described above, when performing plasma spraying processing on the product, the rod member 43 of the selective shutoff device 40 is operated to press the elastic body pipe 42 to press the return pipe 32. Cut off. Then, the thermal spraying powder such as magnesium oxide is supplied from the thermal spraying powder supply device 30 in the continuous operation state together with the carrier gas through the supply pipe line 31 to the plasma flame at the nozzle tip portion of the thermal spray gun 20 and is sprayed. On the other hand, in the case of stopping the thermal spraying due to the removal of the product, etc., while switching the rod member 43 of the selective shutoff device 40 to press the elastic body pipe 41 to shut off the supply pipeline 31,
The return line 32 is connected. Then, the thermal spray powder is supplied from the thermal spray powder supply device 30 in the continuous operation state to the collection container 50 together with the carrier gas via the return pipe 32,
It will be collected here. Needless to say, when restarting the thermal spraying, the rod member 43 of the selective blocking device 40 may be switched again. In this case, the spray powder supply device 30 is in continuous operation and the selective shutoff device
Since the supply pipe 31 from 40 to the spray gun 20 is short, it is possible to stably supply the spray powder without any time delay.

According to this embodiment, the elastic tubes 41 and 42 are used as the shutoff means.
And a rod member 43 provided between these elastic pipes 41 and 42 and capable of press-contacting either one of the two, and the rod member 43 is switched, so that the sprayed powder is caught. There is no fear of such problems, and stable use is possible over the long term.

Although the collection container is provided in the above-mentioned embodiment, it goes without saying that the carrier gas may be directly returned to the thermal spray powder supply device if the carrier gas is appropriately removed.

[Effects of the Invention] As is clear from the above description, according to the present invention, a return pipe is branched into a supply line for sprayed powder, and both pipes are connected to both pipes downstream of the branch. Since the selective shut-off means for selectively shutting off the thermal spray powder is provided, continuous operation of the thermal spray powder supply device can be achieved, the supply of thermal spray powder can be stabilized in a short time, and the waste of the amount of thermal spray powder used and the variation in coating weight can be avoided. Plasma spraying processing can be performed without causing it.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a sectional view showing a selective shutoff device according to an embodiment of the present invention, and FIG. 3 is a block diagram showing a conventional example. 10 ... High frequency generator, 20 ... Thermal spray gun, 3022 ... Thermal spray powder supply device, 31 ... Supply line. 32 …… Return line, 40
...... Selective shutoff device, 41, 42 …… Elastic tube, 43 …… Bar member.

Claims (2)

(57) [Scope of utility model registration request] 1. A return pipe is branched into a pipe for supplying thermal spray powder to a thermal spray gun together with a carrier gas, and communication between the two pipes is selectively cut off to both pipes downstream of the branch. A plasma spraying apparatus, characterized by comprising selective blocking means. 2. The selective cutoff means is composed of an elastic tube provided in the middle of the two conduits, and a bar member that presses the elastic tube into contact with the elastic tube. The plasma spraying apparatus according to claim 1, wherein the plasma spraying apparatus is arranged so as to be press-contacted with each other.