JPS6128038B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal anodizing treatment apparatus.

As shown in FIG. 3, for example, as shown in FIG. 3, a metal anodic oxidation treatment apparatus in which the object to be treated is immersed in a treatment liquid in a treatment tank is used, for example, as shown in FIG. The porous body 31 is provided in
The compressed air supplied from the compressor 34 through the compressed air supply pipe 33 connected to the porous body 31
The processing liquid is ejected from the vent hole to the bottom of the processing liquid in the processing tank 32 to form fine bubbles in the processing liquid, and these bubbles agitate the processing liquid to improve processing efficiency. It is known that bubbles are generated in conventional anodizing processing equipment using pressurized air, which makes it difficult to obtain extremely fine bubbles, and it is also difficult to obtain very fine bubbles, as well as the way the bubbles hit the workpiece immersed in the processing solution. The ion concentration is extremely strong at the bottom, weaker at the sides, and hardly hit by bubbles at the top. Cooling is often performed, but as you move upwards, the ion concentration becomes uneven and cooling is not performed as much, which can cause differences in the thickness and hardness of the oxide film formed on the surface of the processed object and cause uneven color. Become. In addition, this tendency becomes more pronounced as the current density increases, so the current density cannot be increased too much, resulting in many problems such as requiring a long anodic oxidation process time.

The present invention relates to a metal anodic oxidation processing apparatus completed for the purpose of solving the above-mentioned problems.Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

Fig. 1 shows an anodizing treatment apparatus as a first embodiment of the present invention, in which a suitable number of pump connection ports 2 are arranged on the tank wall, and a circulation pipe is connected to the bottom part. A processing tank is provided with a port 3, and a pump 5 is provided in the middle of a pipe line 4 whose one end is connected to the pipe connection port 3 on the outside of the processing tank 1.
At the front end of the tank, an appropriate number of water jet pumps 6 are installed at required intervals to stand up along the tank wall and form countless fine bubbles in the passing treatment liquid by suctioning outside air. The discharge pipe part 7 of No. 6 is inserted and fixed into the pump connection port 2, and the distal end of the discharge pipe part 7 is connected to the object to be processed through the through holes of electrodes A and B set in the processing tank 1. It is aimed at Note that the water pump 6 has a tapered supply section extending from the liquid supply port 7' connected to each branch channel arranged at the front end of the pipe line 4 to the nozzle section 9 at the tip facing the pump chamber 8. A tapered liquid discharge passage 11 is formed in the part extending from the pump chamber 8 to the discharge port of the discharge pipe section 7, and an intake pipe is formed in the pump chamber 8 through the intake hole 12. 1
3, by driving the pump 5, the liquid flow from the nozzle section 9 is controlled while the processing liquid in the processing tank 1 is circulated back into the processing tank 1 through the pipe 4 and the water pump 6. The pressure inside the pump chamber 8 is reduced by the jetting, and outside air is sucked into the pump chamber 8 through the intake pipe 13 and the intake hole 12 and mixed with the passing treatment liquid. It is assumed that the processing liquid in which bubbles have been formed is sent toward the object to be processed. On the other hand, FIG. 2 shows a second embodiment of the present invention, which is an apparatus for anodizing a workpiece having a relatively large surface area, and the difference from the first embodiment is the first embodiment. In this embodiment, the pump connection port 2 is not in the processing tank 1, and the front end of the pipe line 4, one end of which is connected to the pipe connection port 3 at the bottom of the processing tank 1, is connected to the processing tank 1 through the bottom of the processing tank 1. There are also two types of water pumps 6, which are installed in large numbers on the back side of the electrode A at the front end of the pipe 4, with the discharge port of the discharge pipe 7 facing diagonally upward and the other having the discharge port facing diagonally downward. The object to be treated is positioned outside the intersection of the liquid streams ejected through the through holes of the electrode A from the water jet pump 6 whose discharge port is directed diagonally upward and the water jet pump 6 whose discharge port is directed diagonally downward. It is designed so that the processing liquid, in which countless fine bubbles are formed by suction of external air, is sent almost evenly to the entire surface of the object to be processed from the discharge port of the discharge pipe section 7.

In the device constructed in this way, the processing tank 1 is filled with a required amount of electrolyte as a processing solution, and electrodes A and B are set in this processing solution, similar to conventional anodizing processing equipment. Anodic oxidation treatment is performed by placing the object to be treated (C) facing the electrodes (A) and (B) and applying electricity to the object.If the pump 5 is driven during this treatment, part of the treatment liquid in the treatment tank 1 will be oxidized. In this section, water flows from a pipe connection port 3 provided at the bottom of the treatment tank 1, passes through a pump 5, a pipe 4, and is disposed on the back side of electrodes A and B at the front end of the pipe 4. The liquid is sent to the liquid supply port 7' of the pump 6, and passes through the tapered liquid supply path 10, the nozzle part 9, the pump chamber 8, and the discharge pipe part 7 with a tapered liquid discharge path 11 inside. The material to be processed is circulated into the processing tank 1 through the discharge port directed toward the material to be processed C. However, the processing liquid that passes through the water pump 6 and is circulated to the processing tank 1 is depressurized in the pump chamber 8 by the liquid flow ejected from the nozzle part 9, and then passes through the intake hole 12 connected to the intake pipe 13. The outside air is sucked into the pump chamber 8, passed through the liquid supply path 10, and then flows into the processing tank 1 from the discharge port.
When the air is returned to the inside, countless extremely fine bubbles are formed by the suction of outside air, and the discharge port of the water jet pump 6 is covered through the through holes of electrodes A and B. Since it is intended for the processing object C, it has the following features when performing anodizing treatment. That is, in the present invention, since bubbles are generated under reduced pressure by the water pump 6 installed on the back of the electrode, many microbubbles with extremely small bubble diameters are formed, and the microbubbles that are immediately discharged into the processing liquid are The rate of rise in liquid is slow, so the number of microbubbles is extremely large, and the stirring action is large.
In order to circulate and flow out the processing solution into the processing tank, the entire processing solution in the processing tank is increasingly agitated, and the supply of ions is good and the cooling efficiency is also good, so burning does not occur, and therefore the current density can be reduced. This can reduce processing time. Furthermore, since the processing liquid itself that is circulated in the processing tank 1 contains countless microbubbles, the microbubbles uniformly hit the surface of the object to be processed.
The reason for this is that bubbles, especially microbubbles with a diameter of 2.0 mm or less, rise slowly in the liquid as mentioned above, so they easily reach the surface of the object to be treated by riding the flow of treatment liquid from the water pump. Near the surface of the workpiece, the membrane is destroyed by the turbulent agitation action of countless microbubbles and a new treatment liquid is brought to the surface of the workpiece, increasing the efficiency of the anodizing process and making the ion concentration uniform, allowing the anodizing process to proceed smoothly. The thickness of the film is uniform in each part, and each part near the surface of the object to be treated is uniformly cooled, so even if the current density is increased, no burning occurs and the treatment can be completed in a short time. I can do it. The pump pressure of the pump 5 installed in the middle of the pipe line 4 is usually about 0.5 to 10 kg/cm ² , and the size of the bubbles formed in the passing treatment liquid by the water pump 6 is determined according to the treatment purpose. Although it varies slightly depending on the situation, a very small diameter of about 0.01 to 2 mm is effective.

Next, an experimental example of an anodic oxidation treatment method performed using the apparatus of the present invention will be shown.

500 made of aluminum alloy (JIS standard 6063)
A mm x 300 mm x 1 mm plate was anodized using the conventional treatment method using the equipment shown in Figure 3 and the treatment method using the present invention equipment shown in Figure 1, using a liquid composition of sulfuric acid 30W/ V%, temperature 20℃, current density
20A/dm ² , nozzle pressure 3Kg/cm ² , number of nozzles 40/
The anodizing treatment was carried out under the following conditions: 2 sets and a liquid circulation rate of 300/min. As a result,
The anodic oxide film obtained by the conventional method has uneven color at the upper and lower parts, with the upper part being gray and the lower part being grayish-black.When the film thickness was measured with an eddy current film pressure meter, the grayish part at the top was 53μm, and the gray-black part at the bottom was 47μm, with a difference of 6μm between the top and bottom, whereas the film obtained by anodizing with the device of the present invention had a uniform gray tone, and the film thickness was 53μm. When measured, the upper and lower portions were approximately uniform, 51 μm at the top and 50 μm at the bottom.

As is clear from the above description, the present invention is provided with a water jet pump on the back of the electrode that forms countless fine bubbles in the passing treatment liquid by suctioning outside air, and circulates the treatment liquid in the tank. At the same time, the treatment liquid immediately after the bubbles are formed is sent to the object to be treated, so the treatment liquid in the tank is moderately agitated, and the countless particles contained in the treatment liquid refluxed by the water pump are Fine bubbles are extremely effective in performing various surface treatments, and the industry has developed as a metal anodizing treatment device that can significantly shorten treatment time and provide excellent anodizing results. The contribution to this is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing a first embodiment of the anodizing treatment apparatus of the present invention, and FIG. 2 is a partially cutaway front view showing the second embodiment of the anodizing treatment apparatus of the present invention. FIG. 3 is a partially cutaway front view showing an example of a conventional anodizing treatment apparatus. 1: Processing tank; 6: Water pump that forms countless fine bubbles in the passing treatment liquid by suctioning outside air.

Claims (1)

[Claims] 1 A nozzle part 9 that spouts out the processing liquid circulated by the pump 5 is installed on the back side of the electrodes A and B set in the processing tank 1, and outside air is pumped out using the reduced pressure caused by the liquid flow jetted from the nozzle part 9. Suction hole 12 for suction
and a discharge pipe section 7 that discharges a processing liquid containing countless fine bubbles formed by the outside air sucked from the suction hole 12, and a discharge pipe of the water pump 6. A metal anodic oxidation processing apparatus characterized in that the tip of the part 7 is directed toward the object to be processed C through the through holes of the electrodes A and B.