JP2527168Y2 - Diaphragm electrode structure for electrodeposition coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a diaphragm electrode structure for electrodeposition coating formed to reversely flow an anolyte inside and outside a cylindrical electrode.

[Prior Art] A so-called diaphragm electrode device is used in an electrodeposition coating apparatus to remove metal ions eluted from an electrode.

This diaphragm electrode device is formed of a plurality of diaphragm electrode units and an electrode solution management unit and the like, and supplies the electrode solution from an electrode solution management unit externally provided to each of the membrane electrode units provided in the electrodeposition tank. It is configured to maintain the property of the electrode solution in the diaphragm electrode unit constant.

A so-called one-way flow system and a reverse flow system are known as a flow system of the polar liquid in the diaphragm electrode structure which forms the center of such a diaphragm electrode unit.

That is, the one-way flow-type diaphragm electrode structure (10)
As shown in FIG. 4, a cylindrical electrode 15 is provided in a diaphragm structure including an upper holding member 11, a lower holding member 12, and a tubular diaphragm 13 provided between the holding members 11, 12, Supply pipe 21
Are connected to each other by passing through the inside of the cylindrical electrode 15 and penetrating the blind member 16, and the effluent discharge pipe 22 is connected to the discharge hole 11a. Further, a plurality of communication holes 15a are provided below the cylindrical electrode 15. Therefore, the polar liquid flows upward from below in the diaphragm 13 and flows upward from below in the electrode 15 through the communication hole 15a. Thus, the inside and outside of the cylindrical electrode 15 are both cooled by the ascending flow, that is, the polar liquid flowing in one direction. Further, the polar solution in the diaphragm 13 is constantly replaced and maintained in a constant state.

However, in this one-way flow system, the electrode deteriorated by corrosion
The replacement work of 15 is easy, but if there is a failure in the non-illustrated anolyte management unit or the check valve of the piping system, the siphon action will occur because the supply port 12a of the anolyte supply pipe 21 is located below. Works, and the polar liquid flows backward through the polar liquid supply pipe 21, so that the inside of the diaphragm electrode structure 10 becomes empty. Then, the electrodeposition tank 100 is
As a result of applying a large external pressure due to the coating liquid inside, there is a problem that the diaphragm 13 is damaged.

The diaphragm 13 is formed by winding a polyamide film or the like having a thickness of about 0.5 mm around an outer peripheral surface of a cylindrical diaphragm holder made of a porous material having a certain rigidity, and a certain polymer substance. Some are injection molded into a tube, but the problem is substantially the same. This is because forming the tubular diaphragm holding member considerably stiffly increases the size and cost.

On the other hand, as shown in FIG.
Both the polar liquid supply pipe 21 and the polar liquid discharge pipe 22 are connected to the upper holding member 11.
It is configured to be provided on the side. In other words, the polar liquid flows in the cylindrical electrode 15 as a downward flow, reverses in the lower holding member 12, and flows in the diaphragm 13 as an upward flow. Therefore,
The replacement of the cylindrical electrode 15 is easier and the need for the blind member (16) is eliminated, so that the cost can be reduced and the siphon action can be prevented. As an example of this,
No. 4531 can be mentioned.

[Problem to be Solved by the Invention] The reason why the one-way flow system of the polar liquid has been improved to the reverse flow system is primarily because of the cylindrical electrode 15 which is corroded and deteriorated with time under a predetermined load current. The replacement work was to be easy and quick.

However, since it is very difficult to visually check the corrosion deterioration phenomenon from the outside, it is not clear when to replace the electrodes. The fact is that it is operated so that

Therefore, before the electrode replacement time determined in this way, even if a small corrosion hole 15h as shown in FIG. It is no exaggeration to say that there is no even a problem-aware idea of the occurrence of a small hole (15h) and the measures to be taken in that case.

However, according to the applicant's research and analysis through a number of actual facilities that have been performed to meet the demand for higher quality, the size and number of the small holes (15h) and the longitudinal direction on the electrode 15 Depending on the position, it is a factor that greatly affects the coating film quality.

That is, in the reverse flow system, when a small hole 15h or the like is formed in the electrode 15 due to corrosion or the like, a bypass flow (short path) indicated by an arrow B in FIG. 5 is generated, and the anolyte stagnates in the diaphragm structure. Then, inside the diaphragm structure (outside the electrode 15)
The eluted ions accumulate, and as the conductivity of the electrode solution changes, a change in the current value or a loss of the electrode 15 occurs, which causes inconveniences such as partial discoloration of the workpiece coating. In particular, if a small hole 15h is formed on the upper side of the electrode 8, the overall quality is deteriorated, and the operator spends much labor and time to find the cause.

Further, overheating of the electrode 15 may cause an accident such as burning of the diaphragm 13.

Here, an object of the present invention is to prevent electrode solution stagnation due to a short path flow, and to stably guarantee high quality coating film formation while maintaining equipment maintenance and smooth flow of electrode solution. An object of the present invention is to provide a diaphragm electrode structure for coating.

[Means for Solving the Problems] In the present invention, a cylindrical electrode is disposed in a diaphragm structure including an upper holding member, a tubular diaphragm, and a lower holding member, and an anolyte supply pipe and an anolyte discharge pipe are connected. In a diaphragm electrode structure for electrodeposition coating formed so as to connect and reversely flow the polar liquid inside and outside the cylindrical electrode, inside the cylindrical electrode, formed inside and outside the cylindrical electrode through a corrosion hole of the cylindrical electrode A seal cylinder made of an electrically insulating material for preventing a short-path flow is provided.

[Operation] According to the present invention, the anolyte from the anolyte supply pipe flows downward in the cylindrical electrode, reverses in the lower holding member, flows upward in the diaphragm, and reaches the anolyte discharge pipe. Therefore, the anolyte in the diaphragm structure is maintained in a predetermined property and the electrode is cooled.

Even if the electrode has a corroded hole penetrating the inside and outside of the electrode, the seal cylinder made of an electrically insulating material is not corroded by an electrode or the like and has no hole, and the seal cylinder disposed inside the electrode. The short path flow is thereby blocked. Therefore, even in this case, high-quality coating film formation can be smoothly continued.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of the present diaphragm electrode structure, and FIG. 2 is a transverse sectional view.

In the figure, reference numeral 10 denotes a diaphragm electrode structure, and its basic configuration is the same as the configuration of the conventional polar liquid reversal flow system shown in FIG. Therefore, description of the diaphragm electrode structure 10 itself is omitted.

The diaphragm 13 is formed by injection-molding a certain polymer material into a tubular shape. However, a film obtained by winding a film around a porous material may be used.

The cylindrical electrode 15 has a flow path P between itself and the inside of the diaphragm 15.
The diameter is smaller than that of the diaphragm 13 so as to be able to be formed, and in this embodiment, it is made of stainless steel.

Here, a seal cylinder 30 is disposed inside the cylindrical electrode 15. In this seal cylinder 30, a short-path flow caused when a corroded hole 15h shown in FIG. 2 is made in the cylindrical electrode 15, that is, a bypass flow of the polar liquid from the cylindrical electrode 15 to the flow path P (FIG. Arrow S).

Therefore, the seal cylinder 30 has a cross section similar to that of the cylindrical electrode 15 and is formed so as to cover the entire inner peripheral surface of the cylindrical electrode 15. In addition, since the sealing cylinder 30 must not be deteriorated by corrosion similarly to the cylindrical electrode 15 for the purpose, the sealing cylinder 30 is formed from an electrically insulating material.

Furthermore, the cooling effect of the cylindrical electrode 15 due to the downward flow from the polar liquid supply pipe 21 to the lower holding member 12 must not be significantly impaired. Of course, it is necessary to have a certain mechanical strength. Therefore, in this embodiment, it is formed from a vinyl chloride cylinder and inserted into the inner surface of the cylindrical electrode 15.

Since the purpose of the seal cylinder 30 is to prevent a short path as described above, the structure of the seal cylinder 30 itself can be appropriately selected and implemented. For example, FIG.
As shown in (1), a minute gap C may be provided between the cylindrical electrode 15 and the inner surface thereof. In this case, both 15,3
Since the separation of 0 is easy, the assembly and disassembly are easy, and the seal cylinder 30 can be reused.

Further, as shown in FIG. 3 (B), it may be formed from an electric insulating film. Since the mechanical strength can utilize the strength of the cylindrical electrode 15 itself, it can be formed into an ultra-thin film, and has an effect that the cooling effect is not hindered at all.

Thus, according to this embodiment, the sealing cylinder made of an electrically insulating material is provided in the cylindrical electrode 15 forming the diaphragm electrode structure 10.
Because of the configuration provided with 30, even if the cylindrical electrode 15 has a corrosion hole 15h penetrating inside and outside, the seal cylinder 30 does not corrode due to electrodeposition or the like, and can completely prevent the short-path flow of the anolyte. . Therefore, partial or complete discoloration and deterioration of the coating film due to stagnation of the polar solution in the flow path P can be prevented, and a high-quality coating film can be stably formed over a long period of time. There is no room for burning of the diaphragm 13.

In addition, since the sealing cylinder 30 is to be inserted into the cylindrical electrode 15, the two 15, 30 work together to supplement the mechanical strength. As a result, the structure of the two 15, 30 is simplified. it can.

Further, since the seal cylinder 30 is made of vinyl chloride, it can be embodied at low cost and can be reused for a long time.

In addition, the conventional problems such as the work of correcting the current change due to the invisibleness can be eliminated, and the burden on the operator can be reduced.

Furthermore, since the sealing cylinder 30 has a similar shape to the cylindrical electrode 15 and can be attached and detached together with the electrode 15, there is no inconvenience in the conversion work of the electrode 15.

[Effects of the Invention] According to the present invention, a seal cylinder made of an electrically insulating material for preventing a short path flow due to a corroded hole is provided inside a cylindrical electrode having an anodic liquid reverse flow type diaphragm electrode structure. It is possible to eliminate the conventional problems such as discoloration / deterioration of coating due to stagnation of the electrolyte in the diaphragm, current readjustment work, and burnout of the diaphragm, and form a high-quality coating smoothly over a long period of time. It has excellent effects.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a transverse sectional view of the same, FIG. 3 is a view showing a modification, FIGS.
FIG. 4 is a longitudinal sectional view showing a conventional diaphragm electrode structure. FIG. 4 shows a one-way flow system and FIG. 5 shows a reverse flow system. 10: diaphragm electrode structure, 11: upper holding member, 12: lower holding member, 13: tubular diaphragm, 15: cylindrical electrode (cylindrical electrode), 15h
... Corrosion holes, 21 ... Electrolyte supply pipe, 22 ... Electrolyte discharge pipe, 30 ... Seal cylinder, 100 ... Electrodeposition tank.

Claims (1)

(57) [Scope of request for utility model registration] A cylindrical electrode is provided in a diaphragm structure comprising an upper holding member, a tubular diaphragm, and a lower holding member, and an anolyte supply pipe and an anolyte discharge pipe are connected to each other to connect the inside and outside of the cylindrical electrode. In a diaphragm electrode structure for electrodeposition coating formed to reversely flow an anolyte, a short path flow formed inside and outside the cylindrical electrode through a corrosion hole of the cylindrical electrode inside the cylindrical electrode is prevented. A diaphragm electrode structure for electrodeposition coating, comprising a sealing cylinder made of an electrically insulating material.