JPS632617A - Dielectric fluid - Google Patents

Abstract

PURPOSE:To aim at sharp reduction in an electrode consumption rate, by setting an aqueous solution, containing a water soluble polyoxyalkylene compound consisting of the specified chemical formula as much as 0.5-65%, down to a water dielectric fluid. CONSTITUTION:After water is processed with ion exchange resin in advance, a water soluble compound as shown in a formula I (R1 shows hydrogen or a methyl group or an ethyl group, R2 shows a residual group of a bivalent aliphatic organic compound of more than carbon number 3, n shows an integer (mean value) of more than 1) is added as much as 0.5-65%, stirring and dissolving it, thus a water dielectric fluid is produced. If electric discharge machining takes place with this fluid, an electrode consumption rate is held down to 1% to the upmost or less even in case of using it for hours in succession and, what is more, an erosion rate and durability are improved.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention is directed to an electric discharge machining process in which electrical discharge machining is performed by intermittent electric discharge between the electrode and the workpiece. The present invention relates to electroworking fluids for use in electrical processing.

(Prior art) Electrical discharge machining is a method of carving, drilling, or drilling holes in a workpiece by intermittently discharging sparks within an insulating medium between a working electrode and a conductive workpiece. This is a technique for cutting objects. This technique is not affected by the hardness of the object.

Today, it is widely used in various types of metal processing due to its features such as the ability to achieve a surface roughness of ±0.2) 41 or less, which is close to mirror-finish processing accuracy.

Traditionally, mineral oil (kerosene) has been primarily used as the above insulating medium. However, since this mineral oil is flammable, there is a risk of fire if continuous unmanned processing is performed. Therefore, in recent years, attempts have been made to use pure water. However, although water has a high processing speed, it has the disadvantage that it wears out the electrode. Therefore, recently, the addition of various molecular weight control substances to water has been considered, such as glycols such as ethylene glycol, propylene glycol, polyethylene glycol, and polyalkyl ether, or their derivatives, or nonionic substances such as higher alcohols. It has been proposed to add an anionic substance such as polyacrylic acid, acrylamide, guar gum or sodium alginate, or a cationic substance such as chitosan, polyacrylamide or methacrylic acid ester (see, for example, Japanese Patent Publication No. 59-4253).

However, even with this method, the electrode consumption ratio will only decrease to about 3% at most (see Figure 2 of the above publication).In die-sinking and drilling, however, in order to obtain sufficient machining accuracy, the electrode Since it is an absolute requirement that the consumption rate be at most less than 1%, all known aqueous machining fluids are unsatisfactory in terms of practicality.

(Objective of the Invention) The present invention provides an aqueous electrical machining fluid that has an extremely low electrode consumption rate and can maintain the chain wheel at 1% or less even when used continuously for a long period of time. The purpose is to

(Means for Achieving the Object) As a result of intensive research on a large number of new and known nonionic polymer substances, the present inventor has found (1) Chemical formula.

It has been found that the water-soluble bis(polyoxyalkylene) compound represented by (hereinafter referred to as "compound (I)") is extremely suitable as a component of an aqueous electroworking fluid.

What constitutes the main chain of compound (I) here is the residue of a divalent aliphatic organic compound having 3 or more carbon atoms, and specifically refers to the following groups, for example.

C, I3 (p)-7 enylene.

Typical polymer compounds belonging to compound CI) are illustrated below.

OH3 HO(CH2CH20) s -C)12 C-CH2
0(CH2CH20) 5-)1OH3 HO(CHC:ToO)2(CH2CH20)5-CH
2CH2(CH2CH20)5-C)I3-(C)120HO)2)I2H5HO(C)12cH20)ucHGHzO(CH2CH
20boH2I5 HO(CH2H20)l (GHzCH20)+o-
C:>-0(OH2C)I2Q)+o-2I5-(GHz CHO)+H HO(CI2CH20)+o-0-0(OH2C)12
0)+oHHO(CH2CH20)15 G'H2C
Note that in the present invention, one or more compounds that are compatible with compound (I) can be used alone or in combination as necessary.

To prepare the processing fluid of the present invention, water is treated in advance with an ion exchange resin so that its specific resistance becomes 104Ω・Cm or more, and then an appropriate amount of compound (I) is added thereto, stirred, and dissolved. let The preferred concentration is 05-65%,
At this time, a small amount of rust preventive agent may be added if necessary.
In the above preparation operations, ion exchange resin treatment can also be carried out at the end.

(Examples) Hereinafter, embodiments of the invention will be explained using examples, but it goes without saying that the examples do not directly limit the connotation and extension of the inventive idea.

Example 1 [Preparation of processing liquid] Compounds belonging to the above-mentioned compound groups 1 to 4 were dissolved in water, and then passed through an ion exchange resin to prepare a specific resistance value of 2×10 SΩ·cm to prepare a test processing liquid.

[Compound used] It is shown in Table 1 below.

(Margin below) Table 1 [Experimental conditions] It is shown in Table 2 below.

Table 2 [Results] As shown by curves A in Figures 1 to 3, the processing fluids using compounds A-1 to A-4 belonging to compound (I) in the compound group in Table 1 were #, which is superior to the control processing liquid using control compounds C-1 and C-2 in terms of processing speed, electrode wear rate, and durability. The fact that indicates a is evident.

Example 2 Using an aqueous solution prepared by dissolving the compounds shown in Table 1 in pure water that had been previously desalinated using an ion exchange resin as a working liquid, wire cutting was carried out under the following conditions.

Model used: Sodick 330-W Processing electrode: Wire FKHφ0.2mm Workpiece: 5KD-1120Am thickness Processing conditions: Wire feed speed 5m/min Processing fluid resistance value 3 x 104Ω・C11 voltage
35V Current 10A The results are shown in Figure 4. As shown in Figure 4, the processing fluids using each of the compounds A-1 to A-4 belonging to compound (I) in Table 1 were compared to the control compound C. It can be seen that the processing speed is excellent compared to the control solutions using -1 and C-2.

(Effects) As explained above, the electroworking fluid according to the present invention is superior to known aqueous working fluids not only in terms of electrode wear rate but also in machining speed and durability, so it can greatly contribute to the development of metalworking technology. .

[Brief explanation of the drawing]

Figures 1 to 3 are graphs comparing the machining fluid of the present invention and the known machining fluid for die-sinking machining in terms of machining speed and center pole extinction rate. This is a graph comparing the machining speed with known machining fluid.In the figure, the curve indicated by A(-0-) is for the case of using the compound of the present application, and the curve indicated by C(-φ-) is for the case of using the control compound. Cases of use are shown. Patent applicant: Sodiktsu Co., Ltd. No. 3 - Kogyo Seiyaku Co., Ltd. Collection 3 Time for gf (Hrs) % purity of fABa aqueous solution

Claims (2)

[Claims] (1) Chemical formulas, ▲ Numerical formulas, chemical formulas, tables, etc. ▼------- (I) [However, the meaning of each symbol in the above formula is as follows: - R_1: Hydrogen or methyl group or ethyl group. R_2: Residue of a divalent aliphatic organic compound having 3 or more carbon atoms. n: an integer of 1 or more (average value)] An electroworking fluid containing a water-soluble compound shown as an essential component. (2) The electroworking fluid according to claim 1, which is an aqueous solution containing 0.5 to 65% of compound (I).