JPS5819414B2 - Electrolytic buffing processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention utilizes an anodic elution action of the metal of the polished object through electrolysis, and a polishing action that removes the passivated oxide film formed on the surface of the polished object through the mechanical abrasion action of an abrasive. This relates to an electrolytic puff polishing device that combines the above to finish the surface of stainless steel, etc., to a mirror finish.

Conventionally, when finishing stainless steel or the like to a mirror surface, a method has been used in which an object to be polished and an electrode are immersed facing each other in an electrolyte bath, and electrolytic polishing is performed.

However, since this method electrochemically removes the anodic passivation oxide film generated on the surface of the object to be polished and promotes electrolysis, it is limited by the current density, which is 0.2 to 0.7
Only a small value of A/crA can flow.

For this reason, the polishing speed is slow and the removal workability is extremely low, so it is mainly applied to mirror finishing small items that have been finished with a base.

Therefore, as a method for mirror-finishing long and large-area objects, the slow polishing speed, or in other words, the need for surface finishing of the surface to be polished, is a major drawback, and this is why it is not practical. is considered difficult.

Therefore, in order to remove the passivated oxide film that occurs on the surface of the object to be polished, an effective method is the electrolytic puff polishing method, which uses an abrasive to forcibly remove the film and increases the current density. It is.

The present invention takes the above-mentioned points into consideration and provides a processing apparatus that can carry out the electrolytic puff polishing method more effectively.Examples will be described in detail below with reference to the drawings.

First, FIG. 1 and FIG. 2, which show an example of the polishing apparatus of the present invention, will be explained.

In the figure, 1 is a tool connected to a drive shaft and rotated by a drive device, 2 is an electrode support plate on a disk formed on the processing surface side of the lower part of tool 1, and 3 is conductive adhesive bonded to the electrode support plate 2. 4 is a plurality of outlets for electrolytic solution 5 provided through the electrode support plate 2 and the electrode 3; 6 is an electrode on the bottom surface of the electrode 3; The formed cross-shaped exposed surface 7 is an abrasive material such as a puff, abrasive cloth, or a nonwoven fabric, which is adhered with an electrically insulating adhesive 8, leaving the exposed surface 6 on the lower surface of the electrode 3. It may contain appropriate abrasive grains.

Then, the electrolytic solution 5 is pumped through the drive shaft and the outflow port 4
from the abrasive material 7 to the outside of the tool 1.

Reference numeral 9 denotes an insulating film applied to the circumferential surface of the tool 1 in order to prevent leakage current from flowing from the tool 1 through the electrolyte 5. Based on the above configuration, the electrode 3 of the tool 1 and the lower surface of the tool 1 are opposed to each other. The cathode and anode sides of a direct current or pulsed power source are connected to the object to be polished, which is installed in a vacuum cleaner.

During polishing, a direct current or pulse voltage is applied to the electrode 3 of the tool 1 and the object to be polished, and an electrolytic solution 5 is supplied between the electrodes 3 and the object to be polished, and the tool 1 is rotated while being pressed against the object to be polished, thereby producing electrolytic action. The metal to be polished is electrolytically eluted, and the passivated oxide film generated on the surface of the polished object is removed by abrasive material γ, and the convex portions of the irregularities on the surface of the polished object are preferentially and selectively removed. Electrolysis can be effectively promoted, and the surface of the object to be polished can be finished to a mirror finish.

Furthermore, a major feature of this invention is that by using a conductive and elastic electrode 3, we succeeded in further increasing the electrolytic polishing efficiency.Next, we will discuss the experimental results. explain.

Figures 3 and 4 illustrate the cross-sectional shape of the tool used in the experiment, and both have a diameter of 150 m1 on the electrode of the tool.
φ (tool area: 177 cd), cross-shaped electrode exposed surface area: 40 crA, abrasive material is a non-woven abrasive material with a thickness of 8 to 10 mm impregnated with #600 to 800 abrasive grains, electrolyte is by weight ratio Using 20% sodium nitrate (NaN03) aqueous solution, 3 l/mvtQ was pumped to the tool, 8 V DC was applied to the electrode and the object to be polished, and 0.2 kg was applied to the object to be polished.
40 Or while pressing the tool with a pressing force of /c4
Rotate at pm.

Then, the object to be polished is stainless steel (SUS304L), which is roll-formed to a radius R of 1800 mm, and the inner surface of the cylinder, which has been ground-finished to 4 to 6 μ77 ZRmax with paper, is electrolytically polished.

In this case, an electrode having a radius equal to or slightly smaller than the inner radius of the object to be polished is used so that the lower surface of the tool, that is, the electrode surface, matches the curved surface of the object to be polished.

FIG. 3 shows a case where a rigid metal is used for the electrode 3', and FIG. 4 shows a case where a conductive rubber elastic body of the present invention is used for the electrode 3. In the figure, t is an elastic body electrode. The other specifications are the same as in FIGS. 3 and 4.

Figure 5 shows the experimental results, and the vertical axis is 4~
6μRmax base-finished surface to be polished 0.2 to 0
．． The polished area per unit time that can be uniformly polished to a mirror surface of 4 μmRmax is expressed as the polishing speed.

The horizontal axis represents the thickness of the elastic electrode, and the thickness O indicates that the electrode is made of a rigid body as shown in FIG.

Then, the volume resistivity value of the ν elastic body electrode is taken as a parameter, and 10-1Ω-sieve, 10-2Ω-sieve, and 10-
I selected a 3Ω-Fu and experimented with it.

By the way, the inner surface of a large roll-processed can is subject to bending errors that occur during roll forming, welding during can manufacturing, and distortion.
Even though the radius is 1800 mm, there are large undulations and uneven bends locally, and when polishing with an electrode with the same curvature, the actual contact surface will be uneven and the pressing pressure will be uneven. join.

This causes unevenness due to the polished surface, resulting in areas that are quickly finished to a mirror finish and areas where the underlying surface remains forever and is not polished.

This tendency is particularly strong when using a rigid electrode, and the polishing speed is low.

On the other hand, when an elastic electrode is used, the electrode surface closely matches the surface of the object to be polished.

In other words, the electrode surface and the surface of the object to be polished are always in a parallel state and the pressing force is applied uniformly, so even if the surface of the object to be polished has undulations or large irregularities, the electrode shape will deform accordingly. The polishing speed can be increased to accommodate the

; As is clear from Fig. 5, in the case of an elastic electrode with a volume resistivity of 10-2 Ω or less, the thickness is 5.
-10 mm, the polishing speed increases by 10-50%.

However, in the case of a temperature of 10<-1 >ohm, the electric resistance greatly increases as the thickness increases, so that no electrolytic current flows and the polishing speed decreases, so that even if an elastic electrode is used, no effect will be seen.

As described above, according to the electrolytic puff polishing apparatus of the present invention, a polished object having a curved surface can be polished by using an electrode made of a rubber elastic body and having an electrical conductivity of 10-2Ω-temperature or less. The ability to follow the body can be improved, and efficient electrolytic puff polishing can be performed.

Furthermore, since no impact force acts between the surface of the object to be polished and the electrode, the abrasive material lasts a long time.

[Brief explanation of drawings]

Fig. 1 is a bottom view of the tool electrode used in the electrolytic puff polishing device of the present invention, Fig. 2 is a sectional view taken along line ss' of the tool in Fig. 1, and Figs. 3 and 4 are during the experiment. Fig. 3 shows a tool using a rigid body for the electrode, Fig. 4 shows a tool using the elastic body of the present invention for the electrode, and Fig. 5 shows the relationship between the thickness of the electrode and the polishing speed. . 1... Tool, 2... Electrode support plate, 3.
... Electrode, 4 ... Outlet, 5 ...
・Electrolyte, 6...exposed surface, 7...abrasive material.

Claims (1)

[Claims] 1 The metal of the object to be polished is anodic eluted by electrolysis, and the passivated oxide film formed on the surface of the object to be polished is removed by abrasive material, and electrolysis is selectively promoted. In an electrolytic puff polishing device for finishing a material to a mirror surface, a disk-shaped electrode support plate is provided on the processing surface side of the tool, and an electrode made of a rubber elastic body with a specific resistance of 10-2 Ω-sieve or less is provided on the support plate, Electrolytic puff polishing characterized in that a plurality of electrolyte outflow ports are provided through the support plate and the electrode, and an exposed surface of the electrode and an abrasive material are alternately provided on the electrode surface in the rotational direction of the tool. Processing equipment.