JPS6048216A - Electrolytic and mechanical combined grinding method - Google Patents

Abstract

PURPOSE:To attain effective finishing of a dovetail groove, by providing a cone- shaped electrode of similar form to the dovetail groove in cross section with a grinding member mounted thereon, which grinding member includes abraisive grains. CONSTITUTION:A cone-shaped electrode 3 connected to the negative electrode of a d.c. power source is formed in such a way that its cross section is similar to that of the dovetail groove 2 and slightly smaller than the same. The electrode 3 is provided with a plurality of exhaust nozzles 4 of electrolyte 5 on its surface opposing the surface of the dovetail groove 2 to be finished. Further, a grinding member 6 having water transmitting prperty, insulating property, and flexibily, such as nonwoven fabric including abraisive grains, is mounted on the surface of the electrode 3, and thus an electrode tool is provided. The electrode tool is sent into the dovetail groove 2, while being rotated. By the rotation of the electrode tool and the relative movement between the same and the work under the condition of the grinding member pressed against the surface of the dovetail groove to be finished at 0.2kg f/cm<2> or above, the dovetail groove can be finished to 1mumRmax or below within a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolytic composite polishing method for polishing by combining metal elution removal action and abrasive grain abrasion action by electrolytic action,
The purpose is to finish dovetail grooves with a thickness of 1 μm or less at a low cost.

In general, pyrite remains in the dovetail grooves of metal blocks and workpieces that have been processed by cutting, and conventional methods of so-called mechanical polishing such as grinding, lapping, and puff polishing are used to improve the bite. It is being done. However, when the dovetail groove size is small or when it is long, the work efficiency is poor, and the roughness of the dovetail groove is 371 + y + Ro.
+rzχ, and even if a particularly high degree of dovetail groove finishing is required, the industrial limit is about ltnlI1maχ.

On the other hand, O-rings are used in airtight sealing mechanisms required not only for food, medicine, and chemical plants, but also for nuclear power-related equipment, and in this case, dovetail groove processing is essential. [7] Therefore, in order to improve the reliability and safety of equipment, it is necessary to improve the quality of the O-ring material as well as to provide a high-quality finish for the dovetail groove. .

However, in the conventional mechanical polishing method, 1μmRma%
2. Difficult to finish; requires long polishing time;
It is also expensive in terms of cost.

In some cases, the electrolytic polishing method is also a possibility, but it requires a strong acid electrolytic polishing solution and has poor polishing workability due to non-uniform current density distribution and electrolyte temperature control. This method was developed by taking into account the shortcomings of mechanical polishing and electrolytic polishing, and in the electrolytic composite polishing method, which combines metal elution removal action by electrolytic action and abrasive grain abrasion action, it is possible to polish an electrode tool with a cross-sectional surface. An abrasive material containing abrasive grains is attached to a conical electrode having dimensions similar to the cross-sectional shape of a dovetail groove of a metal workpiece and slightly smaller than said shape, and the pressing pressure of the abrasive material against the finished surface of the dovetail groove is 0.2
kyf/cn1 or more, and provides an electrolytic composite polishing method characterized in that the lower electrode R- is rotated and the entire electrode tool and the metal workpiece are moved relative to each other.

Therefore, according to this invention, one dovetail groove can be formed at low cost.
It can be reduced to less than μm Rmax.

Next, the present invention will be explained in detail with reference to the drawings showing one embodiment thereof.

In Figure 1, (1) is a metal workpiece connected to the anode of a DC power source, 121 is a dovetail groove machined in the workpiece (1), and this dovetail groove (2) is cut as usual. The surface roughness is 6 to 1.
It is 25. (31 is a conical electrode connected to the cathode of the blood flow power source, and has a cross section L similar to the cross-sectional shape of the groove (2) and slightly smaller in size than the cross-sectional shape of the dovetail groove (21). (4) is a plurality of electrolytic solutions (5) formed on the surface opposite to the bottom two surfaces of the dovetail groove (2) of the electrode (3).
The spout hole (6) is attached to the entire outer circumferential surface and bottom surface of the electrode 31, that is, the surface facing the two sides of the dovetail groove 121, and is made of water-permeable, insulating and flexible material such as a non-woven fabric containing abrasive grains. The abrasive material (7) is an insulator formed on the outer surface of the support part (8) of the electrode (3), and suppresses the formation of an oxide film or the generation of pits due to leakage current. (9
) is an abrasive material formed continuously with the abrasive material (6) on the outer surface of the insulator (7). The electrolyte (5) is an aqueous solution of neutral salts, such as NaNO3, KNO3, NaCl
etc. are used.

In step 1~, the electrode tool having the above configuration is rotated and fed into the dovetail groove (2), or the tool is fed into the dovetail groove (2) and then rotated to create an Mt+ power source between the workpiece (1) and the electrode (3). is applied and the electrode tool is moved in one direction or reciprocating to finish the entire dovetail groove (2). Or, the dovetail groove formed in the 5US304 material of the metal workpiece facing the workpiece fi+ in one direction has an upper dimension of 20 cm, a bottom length of 500 m, and a depth of 17.5 cm2.
The shape of the side surface is equiangular with an inclination angle of 1°, the roughness of the underlying surface is 6 to 10 μm TLmax, and the electrode tool is fully dimensioned so that the gap between the electrode surface and the dovetail groove surface is constant The abrasive pressing pressure in the gap is 0.2ky f/C
Choose a size that is J or larger. 2. The abrasive pressing pressure is 0.2
When kyf/cni or less, electrolytic action becomes the main
Electrolytic pits occur and the finished surface deteriorates.

The 21st part 1 shows the machining time [and machining surface roughness R] using abrasive grains of Na240, machining current density IOA/cJ, feed rate 1 m/mgn + tool rotation speed 400 rPm.
As is clear from the figure, it is possible to easily obtain a finished surface of 1 μmRxa% or less in a processing time of 6 to 7 minutes, greatly improving production efficiency.
-Can be done.

In addition, if both ends of the dovetail groove are closed, electrode work H,
It can be cut in half and assembled in the groove. Therefore, an electrode tool with an abrasive material containing abrasive particles attached to a conical electrode with a cross-sectional shape similar to the cross-sectional shape of the groove and slightly smaller in size can be used to assemble the electrode in half. By setting the abrasive pressing pressure against the finished surface of the groove to 0.21cgfArj1 or more, and by providing rotation of the electrode tool and relative movement between the electrode tool and the workpiece, the groove can be efficiently reduced to 1μmR-1nax or less during the period of time. It is possible to finish it.

Further, it is sufficient that the accuracy of the electrode tool is 1/10 rma, and the present invention can be applied not only to general machine tools but also to hand-held tools.

[Brief explanation of drawings]

The drawing shows an embodiment of the electrolytic composite polishing method of the present invention,
FIG. 1 is a partially cutaway perspective view, and FIG. 2 is a diagram showing the relationship between machining time and machined surface roughness. (1)...10,000 workpieces in total, (21...dovetail grooves, (3
)... Electrode, (4)... Ejection hole, (5)... Electrolyte, (6)... Abrasive material.

Claims (1)

[Claims] ■ In the electrolytic composite polishing method, which combines the metal elution and removal action by electrolytic action and the abrasive grain abrasion action, the electrode tool has a cross-sectional shape similar to the cross-sectional shape of the dovetail groove of the metal workpiece, and a size slightly smaller than the above-mentioned shape. An abrasive material containing abrasive grains is attached to the conical electrode of j~, the pressing pressure of the abrasive material against the finished surface of the dovetail groove is set to 0.2 to 9 f/ca or more, and the electrode tool is rotated. An electrolytic composite polishing method characterized in that the electrode tool and the metal workpiece are also relatively moved.