JPS6242735B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode tool for electrolytic composite mirror polishing that processes a workpiece metal to a mirror finish by combining the anodic elution action of the workpiece metal by electrolysis and the mechanical abrasive abrasion action. The purpose of this method is to reduce the number of processing steps and efficiently process the metal to be processed into a mirror surface.

As shown in FIGS. 1 and 2, the conventional electrode tool for electrolytic composite mirror finishing has a tool electrode holder 1 rotated by a drive device connected to the cathode of a DC power source, and a disk-shaped electrode tool at the bottom of the holder 1. A rotary tool electrode 2 is integrally and electrically connected, a plurality of electrolyte supply holes 3 are provided radially through the electrode 2, and abrasive grains are attached to a water-permeable elastic nonwoven fabric on the lower surface of the electrode 2. The abrasive material 4 is attached. Then, the abrasive material 4 is applied to the workpiece metal 5 connected to the anode of the DC power source, and the electrolytic solution 7 from the supply path 6 of the holder 1 passes through the supply hole 3 and the abrasive material 4 to the machined surface of the workpiece metal 5. The electrode 2 together with the holder 1 is
By rotating the machine, the machined surface of the metal to be machined 5 can be mirror-finished efficiently in a short time.

In this case, it is a combination of electrolytic elution action and abrasive grain abrasion action, with the abrasive action mainly having the role of creating surface roughness, and the electrolytic action mainly having the role of determining the removal amount. However, in both cases, the abrasive action is an electrolytic action, and the electrolytic action is an auxiliary action to the abrasive action, that is, they have a combined effect. In particular, the creation of surface roughness is highly dependent on the action of the abrasive grain, but the spring constant of the abrasive used here is extremely small, about 1/10 ⁴ of the normally used vitrified grinding wheel, so the mechanical precision , it creates a relatively uniform and small surface roughness mainly because it is less affected by rotational accuracy.

By the way, the roughness of the machined surface and the amount of processing using a conventional electrode tool largely depend on the grain size of the abrasive grains contained in the abrasive material 4, and the relationship between the grain size of the abrasive grains and the roughness of the machined surface is shown in Fig. 3. As shown, the larger the abrasive grain size, that is, the smaller the grain size, the smaller the surface roughness, and the smaller the grain size, the larger the processing amount.

Therefore, when finishing from a surface roughness of a few to several μmRz to a mirror finish of 0.05μmRz, for example, rough processing with #200 to #300 abrasive and finish the surface by 0.5μm.
around Rz, then 0.1 μm Rz at #600 to #800
Medium finish, then use #1000 to #2000 abrasive.
A similar method is used to obtain a mirror surface of 0.05 μmRz, and the processing steps are complicated.

On the other hand, machining marks as shown in FIG. 4 are marked on the surface machined by the electrode tool shown in FIG.
The unevenness of these striations is the roughness. The streaks become thinner as the specularity increases, and are visible to the naked eye.
It becomes invisible at around 0.03μmRz. Since the streaks indicating this roughness approximately correspond to the diameter of the tool electrode, it can be seen that the roughness is determined by the outer peripheral portion of the disk-shaped tool electrode surface shown in FIG.

Therefore, an electrode tool as shown in FIGS. 5 and 6 can be considered.

In FIGS. 5 and 6, 8 is a tool electrode holder rotated by a drive device and connected to the cathode of a DC power supply, and 9 is a disc-shaped rotating tool electrode that is integrally and electrically connected to the lower part of the holder 8. , 10 is a plurality of circular electrolyte supply holes provided through the electrode 9, 1
Reference numeral 1 denotes an abrasive material for rough machining disposed at the center of the lower surface of the electrode 9, in which abrasive grains having a small abrasive grain size are attached to a water-permeable elastic nonwoven fabric. Reference numeral 12 denotes a finishing abrasive material attached to the lower surface of the electrode 9 and disposed on the outer periphery of the rough machining abrasive material 11, in which abrasive grains with a large abrasive grain size are adhered to a water-permeable nonwoven fabric. 13 is a supply hole and abrasive material 1 from a supply path 14 of the holder 8.
1 and 12, the electrolytic solution flows out onto the processing surface of the metal to be processed.

For example, if the roughness of the base surface of the metal to be processed is several μmRz, the abrasive material 1 at the center of the electrode 9
The abrasive grain size of 1 is #200 to #300 and the diameter is φ180 mm, the abrasive grain size of the abrasive material 12 on the outer periphery is #600 to #800 and the outer diameter is φ240 mm, and the machining current is 300 to 500 A, and the tool feed rate is 300 to 500 mm. /min, the machining depth is 8 to 15 μm and the machined surface roughness is 0.1 μm Rz.

Furthermore, by placing a #1000 to #2000 abrasive material on the outer periphery, the process was previously done in three steps.
Mirror finishing of 0.05μmRz is possible in one process.

However, in the electrolytic composite mirror finishing method that combines the anodic elution action of the workpiece metal by electrolysis and the mechanical abrasive abrasion action, especially in the mirror surface creation region of 0.3μmRz or less, the electrolytic conditions and abrasive abrasion work are Balancing conditions are required, too strong electrolytic action will result in a cloudy surface, and the larger the abrasive grain size, the smaller the electrolytic action (mainly current).

This invention has been made with the above-mentioned points in mind, and is capable of mirror-finishing the workpiece metal by combining the elution and removal action of the anodic workpiece metal through electrolytic action and the mechanical abrasive abrasion action. In the electrode tool for electrolytic composite mirror finishing, an abrasive material for rough machining is provided on the entire lower surface of the disc-shaped rotary tool electrode, an annular insulator is integrally provided on the outer periphery of the tool electrode, and the insulator is This is an electrode tool for electrolytic composite mirror finishing, which is characterized by having an abrasive material for finishing on the lower surface.

Therefore, according to the present invention, the abrasive material for rough machining is provided on the entire lower surface of the tool electrode surface, and the abrasive material for finish machining is provided on the outer periphery of the abrasive material, so that the central part is The abrasive material can be used for base processing, and the abrasive material on the outer periphery can be used for finishing processing, which not only reduces the number of processing steps, but also allows finishing on the bottom surface of the annular insulator provided on the outer periphery of the electrode. Since the processing abrasive material is provided, the abrasive grain rubbing conditions by the finishing abrasive material are properly balanced with the leakage current from the central electrode, which prevents the electrolytic action from being too strong and causing a cloudy surface. However, it has a remarkable effect especially when applied to the mirror surface creation region of 0.3 μmRz or less.

Next, a seventh embodiment of the present invention will be described.
This will be explained in detail with reference to FIG.

In those drawings, the same symbols as in Fig. 5 are
The same thing is shown, and the difference is as follows.

That is, an abrasive material 15 with a small abrasive grain size is attached to the entire lower surface of the disc-shaped rotary tool electrode 9, and an abrasive material 16 with a large abrasive grain size is attached to the lower surface of an annular insulator 17 attached to the outer periphery of the electrode 9. This is the point where it was installed.

Therefore, the abrasive rubbing conditions caused by the abrasive material 16 having a large abrasive grain size in the outer peripheral portion are appropriately balanced with the leakage current from the electrode 9 in the central portion.

According to experiments, this leakage current shows a nearly linear decrease in a range of 15 to 30 mm from the outer peripheral edge of the electrode 9, and the dimensions of the insulator 17 are also determined by this leakage current range. is desirable.

[Brief explanation of the drawing]

Figure 1 is a cutaway front view of a conventional electrode tool, Figure 2 is a bottom view of the tool in Figure 1, Figure 3 is a diagram showing the relationship between abrasive grain size and machined surface roughness, and Figure 4 shows machining marks. Figure 5 is a cutaway front view of the electrode tool that is the premise of this invention, Figure 6 is a bottom view of the tool in Figure 5, and Figure 7 is
The figure is a cutaway front view of one embodiment of the invention, and FIG. 8 is a bottom view of the tool of FIG. 7. 9... Tool electrode, 10... Supply hole, 15, 16
... Abrasive material, 13 ... Electrolyte, 17 ... Insulator.

Claims (1)

[Claims] 1. In an electrode tool for electrolytic composite mirror finishing, which mirrors the workpiece metal by combining the elution and removal action of the anodic workpiece metal by electrolytic action and the mechanical abrasive abrasion action, a disk-shaped rotary tool electrode is used. An abrasive material for rough machining is disposed on the lower surface of the tool electrode, an annular insulator is integrally provided on the outer periphery of the tool electrode, and an abrasive material for finish machining is disposed on the lower surface of the insulator. Electrode tool for electrolytic composite mirror finishing.