JPS5931709Y2 - Aluminum anodizing treatment tank - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an aluminum anodizing treatment tank.

For example, a tank for anodizing aluminum in which a diffuser pipe with numerous minute ventilation holes is provided at the bottom of the tank is described in Japanese Utility Model Publication No. 55-9646. By generating air bubbles, it is possible to reduce the occurrence of burning defects on the processed product even when the current density is large, but on the other hand, it reduces the thickness of the oxide film formed on the processed product. There is a problem that the results are non-uniform.

Therefore, if there is a part where the thickness of the oxide film is less than the standard, it is necessary to continue electrolysis until the thickness of the oxide film reaches the standard, which has the disadvantage of poor efficiency and the undesirable problem of current flow. .

The present invention was developed in order to solve the above-mentioned difficulties in the aluminum anodizing treatment tank, which is equipped with an aeration tube equipped with numerous minute ventilation holes at the bottom.The illustrated embodiment will be described in detail below. explain.

Reference numeral 1 denotes a treatment tank, and at the bottom of the treatment tank 1, an aeration pipe 2 equipped with numerous minute ventilation holes is provided horizontally, and the tip of the aeration pipe 2 is closed inside the tank. By connecting to the compressor 5 outside the tank and sending pressurized air of 0.4 kg/cm2, microscopic particles are introduced into the electrolyte through countless minute ventilation holes with a diameter of 8 to 12μ formed in the cylindrical wall inside the tank. It is made of a material that is not easily corroded by the electrolyte, such as ceramics or rust-free steel.

Reference numeral 4 denotes electrolyte circulation pipes installed in parallel in the vicinity of diagonally upper sides on both sides of the aeration pipe 2 in the treatment tank 1. The electrolyte circulation pipe 4 is connected to a liquid sending pump 6 as one pipe outside the tank, and the electrolyte in the processing tank 1 is supplied to the upper part of the tank wall of the processing tank 1. The liquid is circulated to the liquid sending pump 6 through the provided liquid drain hole 7.

An anode rod (not shown) is placed horizontally above the processing tank 1 and is connected to the anode rod, which is suspended vertically within the processing tank 1. An aluminum plate of the processed product is attached to the anode rod using a rack jig. Similarly to the conventional anodic oxidation treatment tank, a cathode plate (not shown) is placed in the treatment tank 1, and electrolysis is performed by connecting the anode rod and the cathode plate to a power source.

With this structure, if compressor 5 is used to send pressurized air to the aeration pipe 2 provided at the bottom of the processing tank 1, which is equipped with countless minute ventilation holes, the electrolyte in the processing tank 1 will be filled with air. Fine bubbles will be generated and rise,
At this time, there are differences in the size and amount of bubbles generated due to the non-uniformity of the countless minute ventilation holes formed in the aeration pipe 2, and as a result, the rising speed of the bubbles also varies from part to part of the aeration pipe 2. This causes large differences in the flow of the electrolyte depending on the location, and as a result, there are differences in the temperature of the electrolyte depending on the location. Although it is unavoidable that the film thickness of Since the aeration cylinder 2
At the same time, the electrolyte that is circulated through the drain hole 7 provided in the upper part of the tank wall of the processing tank 1 is electrolyzed in the processing tank 1 using a liquid sending pump 6 connected to the electrolyte circulation pipe 4. If the liquid circulation pipe 4 is made to flow out toward the atomization pipe 2 through a large number of outflow holes 3, this uniform flow of the electrolyte will be caused by the location of the electrolyte based on the bubbles generated by the aeration pipe 2 as described above. The flow, which has a large difference between the two, is completely rectified in the vicinity of the aeration tube 2, so that the temperature of the electrolyte in the treatment tank 1 has little difference in temperature, and the minute air bubbles generated by the aeration tube 2 are removed from the treated product. The surface of the treated product on which an oxide film is formed is cooled by raising the temperature uniformly along the surface of the product.

As a result, even if the current density is increased to generate a hard oxide film on the processed product, there will be no seizure (panning) defects on the processed product, and the thickness of the oxide film that is formed is uneven. Therefore, aluminum can be anodized efficiently in a short time without the need for electric current.

In the embodiment described above, one aeration pipe 2 is provided horizontally at the bottom of the treatment tank 1, and the aeration pipe 2 is installed near the diagonally upper side on both sides.
Electrolyte circulation pipes 4 equipped with a large number of outflow holes 3 for causing electrolyte to flow out are provided in parallel.
When the treatment tank is made large, a large number of aeration pipes can be installed horizontally in parallel at the bottom of the treatment tank within the allowable range, and an electrolyte circulation pipe can be installed in parallel for each of them as described above. Often, in such cases, the electrolytic solution is overflowed from the upper periphery of the processing tank, and the electrolytic solution is once flowed into a separately provided circulation electrolyte storage tank, and then a liquid sending pump installed in the storage tank is used. The electrolyte may be circulated through an electrolyte circulation pipe provided with a large number of outflow holes in the processing tank.

As is clear from the explanation of the above embodiments, the present invention solves the drawbacks of the conventional aluminum anodizing treatment tank, which is simply equipped with an aeration tube with numerous minute ventilation holes at the bottom of the treatment tank. It is something that has been completely wiped out, and has enormous practical value.

[Brief explanation of the drawing]

The drawing is a partially cutaway perspective view showing an embodiment of the present invention. 1: treatment tank, 2: aeration pipe, 3: many outflow holes for draining the electrolyte, 4: electrolyte circulation pipe.

Claims (1)

[Scope of utility model registration request] In the vicinity of the aeration pipe 2 provided at the bottom of the treatment tank 1 and equipped with countless minute ventilation holes, an electrolyte circulation pipe 4 equipped with a large number of outflow holes 3 for flowing the electrolyte toward the aeration pipe 2 is installed in parallel. An aluminum anodizing treatment tank characterized in that it is provided with: