JPS62236623A - Electric discharge machining fluid - Google Patents

Abstract

PURPOSE:To enable an electrode consumption rate to be held in an epoch- making low level, by using a water solution, in which the content of 0.5-85% alkoxyoxyethylene derivative as a water soluble compound is added as an essential component, for the machining fluid. CONSTITUTION:The electric discharge machining fluid uses a water solution such that water, after it is previously processed by ion exchange resin so as to obtain the specific resistance of about 10<4>OMEGA.cm or more, adds 0.5-85% alkoxyoxyethylene derivative as shown by a general formula (I) to be stirred and dissolved (where R1 is single or plural optional replacement radicals in alkyl group of carbon number 1-4, R2 is single or plural optional replacement radical in hydrogen methyl group, ethyl group and n is integer within a range of 4-100). If the water solution A, as described in the above, is used as the machining fluid, an electrode obtains not only a low consumption rate but also an excellent machining speed.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention provides a method for performing electrical discharge machining by causing intermittent electrical discharge between an electrode and a workpiece. This invention relates to an electroworking fluid for intervening.

(Prior technology) Radiation machining is a method of carving or drilling holes in a workpiece by intermittently discharging sparks within an insulating medium between a working electrode and a conductive workpiece. It is a technique for cutting objects. This technology is not affected by the hardness of the object and has a surface roughness of ±02#q or more.
It is popular for its features such as a near-mirror finish and high precision, and is now widely used for various metal processing.

Traditionally, mineral oil (kerosene) has been primarily used as the 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 Jil control substances to water has been studied, 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 anionic substances such as polyacrylic acid, acrylamide, guar gum, or sodium alginate, or cationic substances such as chitosan, polyacrylamide, or methacrylic acid ester (for example, see 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). However, in die-sinking and drilling, in order to obtain sufficient machining accuracy, Since it is an absolute requirement that the amount be less than 1% at most, all known aqueous machining fluids are unsatisfactory in terms of practicality.

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

(]] Means for achieving the objective) The present inventor has discovered that a large number of new and known nonionic polymers -
As a result of intensive research on substances, we have found that water-soluble aliphatic ether compounds containing at least four substituted or unsubstituted oxyethylene groups in one molecule are extremely suitable as components of aqueous electroworking fluids. I found it. That is, one feature of the present invention is that the electroworking fluid contains an alkoxyoxyethylene derivative represented by the general formula as an essential component.

Here, examples of the substituent R1 in compound (I) are:
Examples include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, and secondary butyl group. The compound (I) actually used may be a single compound containing a single group or a mixture with a compound containing another type of group, and the substituent R2 may be hydrogen, methyl, etc. Regarding the device substituent R2 consisting of a group and an ethyl group, the compound (1) can also be a compound of the type used or a mixture of several types of compounds.

Further, the polymerization number n of the oligo- or polysubstituted or unsubstituted oxyethylene group represented by the general formula ACH20HO'rr- is preferably within the range of 4 to 100 ('F uniform number). If n is less than 4, the electrode consumption rate will not be reduced sufficiently, and if n exceeds loo, the viscosity of the aqueous solution will increase, making the work difficult. Incidentally, specific examples of compound (I) include the following compounds.

In addition, in this invention, each compound belonging to compound (I) above can be used individually or in combination as needed.

To prepare the additive solution of the present invention, wood is treated in advance with an ion exchange resin so that its specific resistance becomes 104 Ωcm or more, and then an appropriate amount of compound (I) is added thereto, Stir to dissolve. The preferred concentration is 05 to 85%, but at this time, if necessary, a rust inhibitor may be added a little earlier.
In addition, in the above preparation operation, ion exchange resin treatment can also be performed at the end.

(Examples) Hereinafter, the modes of carrying out the invention will be explained using examples, but it is natural that the examples do not directly limit the connotation and extension of the inventive idea.

Example 1 [Preparation of processing liquid 1 After dissolving a compound belonging to the above compound (I) in water, the solution was prepared by passing it through an ion exchange resin so as to exhibit a specific resistance value of 2 x 105 Ωcm] - liquid And so.

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

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

Table 2 [Results] As shown by curves A in Figures 1 to 3, the processing fluids using compounds A-1 to A-3 belonging to compound (I) in the compound group in Table 1 were It can be seen that 21 Kejitsu shows superior performance compared to the control compound C- or C-2 in terms of processing speed, electrode wear rate, and durability. Example 2 A wire cutting process was carried out under the following conditions using an aqueous solution prepared by dissolving the compounds shown in Table 1 in pure water that had been previously removed using an ion exchange resin as a processing liquid.

Model used: Sodick 330-Ill processing electrode:
Wire FKHφ02 wire Workpiece: 5KD-1120mm thickness Processing conditions: Wire feed speed 5m7min Processing liquid resistance 4 (13X104Ω・0 layer voltage 35V Current 10A The results are shown in Table 1 as shown in Figure 4. Among the compound groups, the processing solution using each compound A-1-A-3 belonging to compound (I) had an I:L higher than the control solution using control compound C- or C-2. It can be seen that it indicates the machining speed.

(Effects) As explained above, the electrical machining fluid according to the present invention is superior to known water-based machining fluids not only in glare reduction ratio but also in machining speed and durability, and thus contributes to the development of metal processing technology. can be greatly enriched.

[Brief explanation of drawings]

Figures 1 to 3 are graphs comparing the working fluid of the present invention and the known working fluid for die-sinking machining in terms of machining speed and electrode depletion rate. It is a graph comparing known machining fluids with respect to machining speed. In Figure 1, the curve indicated by A (-〇-) indicates the case of using the present compound, and the curve indicated by C (-Meiichi) indicates the case of using the control compound. (Left below) Challenging 1 picture gap lJwJ Fuyukikojime 11/. Figure 3, Figure 4, Gap 7J091j Water dissolution concentration (1,) Voluntary amendment to the procedure) June 7, 1985, 2, Title of the invention: Electric machining fluid - Toru 3, Relationship with the person making the amendment Patent application Address: 15-1-4, Shin-Yokohama-me, Kohoku-ku, Yokohama City, No agent 6, ``Claims'' section of the specification subject to amendment 97, Contents of the amendment, 7ri, 2. Claims An electroworking fluid characterized by containing a water-soluble compound represented by the following general formula (1) as an essential component. ■ Contains 0.5 to 85% of the compound according to claim 1. The electroworking fluid according to claim 1, which is an aqueous solution.

Claims (2)

[Claims] (1) A water-soluble compound represented by the following general formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ (I) [However, in the formula, R_1 is any arbitrary alkyl group selected from alkyl groups having 1 to 4 carbon atoms. R_2 represents one or more substituents selected from hydrogen, methyl and ethyl groups, and n represents an integer (average number) of 4 to 100. ] An electrical processing fluid characterized by containing as an essential component. (2) 0.5 to 85% of the compound according to claim 1
The electroworking fluid according to claim 1, which is an aqueous solution containing.