JPS582280B2 - Improved electrical machining fluid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to processing used in electrical machining called electrical discharge system or electrolytic system, such as electrical discharge machining, wire cut electrical discharge machining, electrolytic machining, electrolytic grinding, electrical discharge electrolytic machining, electrolytic deburring, etc. Regarding improvement of liquid.

Conventionally, electroworking fluids have been mainly composed of highly insulating hydrocarbon oils.

In the case of this liquid, there was a drawback that the machining speed was reduced due to cutting powder, liberated decomposed carbon, etc. generated during machining.

Moreover, unfavorable results were brought about in terms of the roughness of the machined surface and the machining speed.

In addition, a machining fluid that improves the above-mentioned drawbacks by using an emulsion-like liquid prepared by adding water to insulating oil, and a machining liquid using an emulsion-like liquid prepared by adding and mixing an electrolyte to insulating oil have been used.

Although these cases were improved compared to the case of using only insulating oil, it was still not sufficient.

Therefore, by improving the machining fluid, it is possible to improve the machining speed and stability, remove cutting powder, improve the relative efficiency of machining surface roughness and machining speed, stabilize electrode wear, and prevent rust on the machining surface. It has been requested.

In view of these problems, it is an object of the present invention to provide a processing fluid that improves the above-mentioned drawbacks.

Another object of the present invention is to provide a machining fluid that has hydrocarbon oil and water as its main components and can be used to suit a predetermined machining speed or a predetermined machining surface roughness by changing the composition ratio of the hydrocarbon oil and water.

Another objective is to provide a machining fluid that has a rust-preventing effect on machined surfaces.

Another object of the present invention is to provide a processing fluid containing hydrocarbon oil and fat as the main components and water, which can more easily achieve the above-mentioned objectives by adding a rust preventive agent and a surfactant.

Next, an outline of the present invention will be described.

Kerosene, transformer oil, silicone oil, vaseline oil, paraffin oil, mineral oil and other hydrocarbon oils, or mixed oils of these, which have been used as the main components of conventional processing fluids, and water are added, and if necessary, an appropriate amount of electrolyte is added. The mixed water is added and mixed, and ultrasonic waves are applied to produce an emulsion-like liquid, which is used as a processing liquid.

The water used is mainly distilled water or water treated with ion exchange resin, but tap water is sometimes used.

Furthermore, in order to provide a rust-preventing effect, a necessary amount (several percent or less) of a rust-preventive agent and a surfactant are added to form a uniformly dispersed colloidal processing fluid.

When such an emulsion of hydrocarbon oil and water is used for electrical discharge machining, a slight electrolytic effect also works, increasing the machining speed, reducing the roughness of the machined surface, and preventing the machined surface from being dispersed. Rust prevention is maintained by the rust agent, enabling high precision and high efficiency machining.

Characteristics can be utilized by changing the amount of water added.

Furthermore, in electrolytic machining, leakage current is prevented by emulsified oils and fats, resulting in improved machining accuracy.

Next, one embodiment of the present invention will be described.

FIGS. 1 and 2 are side sectional views showing the relationship among a workpiece, an electrode, and a work fluid in electrical machining.

FIG. 3 is an exemplary diagram showing the relationship between machining speed ratio and oil/water mixing ratio, and FIG. 4 is an exemplary diagram showing the relationship between machined surface roughness and machining speed.

These will be explained. Figure 1 shows the state of electrical discharge machining.
When connecting the workpiece 1 with the wire 5 and the processing electrode 2 with the wire 4 to a power source, and placing the electrode 2 facing the surface of the workpiece 1 and applying a voltage, the gap between the workpiece 1 and the electrode 2 is Electric discharge occurs via the machining fluid 3.

Depending on the mixing ratio of oil and water, machining fluid can take the form of water droplets in oil or oil droplets in water, but water droplets in oil are electrically charged and form a state of easy discharge, and water droplets come into contact with the machined surface and cause electrolytic action. to reduce machined surface roughness and increase machining speed under rough machining conditions.

In addition, the oil droplets in the water control underwater discharge and prevent arcing, making underwater finishing stable, and increasing the processing speed by increasing the generation of high frequency waves.

In the figure, numerals 6 and 7 indicate water droplets in oil or oil droplets in water.

As rust preventive agents, for example, solutions of carbonates, chlorides, phosphates, sodium sulfonate, sorbitol, lauryl aliphatic, etc. can be added to disperse particles containing the generated ions. When mixed, this protects the processed surface exposed by processing, prevents rust, and maintains the activated surface.

In addition, the lauryl aliphatic acid etc. are also surfactants,
This dispersion improves the flow of the liquid in the processing area.

As a result, the machining speed is increased, the machining fluid flows normally, carbon content and cutting powder are removed well, electrical machining is promoted, and the cutting surface is improved.

This effect differs depending on the composition ratio of hydrocarbon oil and water.

Therefore, by using an appropriate composition ratio, it is possible to obtain a predetermined machining speed or machining finish roughness.

As shown in FIG. 4, curve 11 is the one of the present invention, and curve 12 is the conventional one, and is shown as a dotted line.

The machining fluid of the present invention is excellent in the practical machining area where the roughness of the machined surface is approximately 30μRmax or less,
When it exceeds max, the machining speed in machining fluid using only conventional insulating oil increases.

The roughness μRmax of the finished surface with respect to the machining speed g/min shown in FIG. 4 was determined by maintaining the discharge conditions within the range of 3 to 15% of electrode consumption.

Now, for example, to obtain 10μRmaX, with the conventional solution,
The processing speed is approximately 0.1 g/min, but when the processing fluid of the present invention is used, it is 0.25 g/gm.

In addition, in order to obtain 3oμRmax or more, conventional processing fluids and
The machining speed is almost the same.

In the case of FIG. 4, the amount of water mixed in the processing liquid of the present invention, that is, the ratio of water/processing liquid was 60.

The oil is a hydrocarbon fat.

Further, when the machining speed ratio is set to 1 when only oil is used, and the water/oil mixing ratio is shown in terms of the relationship between water/machining fluid (oil + water + rust preventive agent), it becomes as shown in Fig. 3.

In addition, sorbitol 1 is used as a rust preventive agent (including surfactant).
% and lauryl fatty acid were mixed at 0.01%.

Curve 13 showed finishing machining, and curve 14 showed rough machining.

The shaded region 15 indicates the range where the roughness is 15 μRmax or less, and the region 16 indicates the range where the roughness is 15 μRmax or more.

In FIG. 4, the electrode consumption was in the range of 3 to 15%.

When the roughness of the finished surface is divided into rough machining when it is 15μRmaX or more, and finish machining when it is less than the same, the finishing machining speed ratio is good when the water/processing fluid ratio is 60% or more, which includes region 15 where the hydrocarbon oil composition is small. Therefore, the rough machining speed ratio is good when the water/machining fluid ratio is 60% or less, which includes region 16 where the hydrocarbon oil composition is high.

Further, FIG. 4 shows the machining speed ratio due to changes in the composition of oil and water, with the machining speed when only oil is used and no water is added being 1.

This emulsion liquid of oil and water can well disperse and mix the rust preventive agent and surfactant used in conventional methods, so it can be used by uniformly dispersing and adding it, and the results when actually used are good. Met.

As already mentioned, the processing liquid of the present invention is an emulsion-like dispersion of carbohydrate oil and fat, and has a normal composition ratio that increases processing speed and has good processing roughness. As shown in the example, to increase the machining speed according to the machining roughness, use an appropriate composition ratio, and by changing the composition ratio in this way, the machining roughness, According to the speed and electrode wear rate,
Can be electrically processed.

Furthermore, since a rust preventive agent is added and dispersed at the same time, it has the effect of improving the rust prevention of the machined surface.

In addition, in the case of electrolytic machining fluids such as electrolytic machining fluids, electrolytic grinding fluids, electrolytic discharge machining fluids, and electrolytic deburring fluids, electrolyte mixed water is mixed in addition to water to reduce the oil content to oil droplets in water. It can be made into a mold, and by adding a rust preventive agent and a surfactant, stable processing without rust can be performed efficiently.

Conventionally used electrolytes are KNO3 and KNO.
2, NaNO3tNaNO2tNa2COstNa2
Salts such as 804 are used and mixed in a controlled manner depending on the processing mode.

In this way, extremely beneficial effects are brought about, such as improving the workability of electrical machining, improving productivity, and improving machining quality.

[Brief explanation of drawings]

1 and 2 are side sectional views of an electrical processing apparatus illustrating a mode of use of the present invention. FIG. 3 is a diagram showing the relationship between water/machining fluid, %, and machining speed ratio when machining speed using only hydrocarbon oil is set to 1. Figure 4 is a diagram showing the relationship between the roughness of the machined surface and the machining speed. 1... Processed body, 2... Electrode, 3...
...Machining fluid, 4,5...Electric wire, 6,7...
... Emulsion particles, 11 ... Relationship curve between machining speed and machining roughness of the present invention, 13, 14 ... Relationship curve between water/machining fluid % and machining speed ratio.

Claims (1)

[Claims] 1. A machining fluid for electrical machining that has hydrocarbon oil and water (including electrolyte mixed water) as its main components, and a rust preventive agent that has a rust preventive effect on the machined surface, and a surface An appropriate amount (several inches or less) of an activator or a combination thereof is added and mixed well to form a uniformly dispersed emulsion-like liquid, and the mixing ratio of the hydrocarbon oil and water is adjusted according to the processing speed, predetermined electrode wear rate,
An improved electrical machining fluid characterized by using a fluid that is modified to suit the finish roughness of the machined surface or a combination of certain elements among these. 2 When performing electrical discharge machining, the machined surface finish should be 15μ
When rough machining is performed over Rmax, the amount of water mixed should be 60%.
The improved electrical machining fluid according to claim 1, wherein the amount of water mixed is 60% or more when finishing with the same finish level of 15 μRmaX or less.