JPH06170647A - Powder enriched dispersion liquid-like material and powder dispersion electric discharge machining liquid - Google Patents

Abstract

PURPOSE:To provide a powder enriched dispersion liquid-like material for giving powder dispersion electric discharge machining fluid capable of machining a workpiece into a smooth surface with improved machining accuracy and the power dispersion electric discharge machining, liquid of utilizing this liquid- like material. CONSTITUTION:In a powder enriched dispersion liquid-like material electric discharge machining powder is dispersed in electric discharge machining liquid uniformly microchemically in an enriched condition in soluble liquid, to obtain the power enriched dispersion liquid-like material by kneading the power mixed in the soluble liquid.

Description

Detailed Description of the Invention

[0001]

[Industrial applications]

[0002]

2. Description of the Related Art Conventionally, electric discharge machining using a powder-mixed electric discharge machining fluid (hereinafter abbreviated as powder-mixed machining fluid) is known, and the following proposals have been made. (1) Add the amount of conductive powder of the machining liquid in the machining gap (gap between the machining electrode and the workpiece) according to the desired machining expansion margin, and thereby expand the machining by using the discharge generated by the conductive powder. There is a proposal to control the generation (Japanese Patent Publication No. 52-263).
No. 57).

Therefore, the conductive powder used is 10 to 1 in the form of metal powder or graphite having a particle size of 5 to 10 microns.
It is a mixture of metal powder or graphite powder having a particle diameter of 00 angstrom. The concentration of the conductive powder is 0.05 to 15 g / l. (2) There is a proposal that a paste prepared by kneading a conductive powder, a magnetic powder, and an electric discharge machining liquid is applied to a portion of a workpiece to be finish-machined for electric discharge machining, and the applied portion is discharged for finishing. (See Japanese Patent Publication No. 54-20718).

The conductive powders used therein are graphite, brass, tungsten, silver, alloys of tungsten and silver, copper and alloys of copper and tungsten, and magnetic powders are powders of barium ferrite and high carbon steel. is there. (3) There is a proposal to stabilize electric discharge machining and increase the discharge distance between electrodes by performing electric discharge machining with a powder-mixed machining liquid in which a metal powder having a low evaporation temperature is mixed (JP-A-54-159798). reference). (4) EDM is performed with a powder-mixed machining fluid that mixes metal powders that easily evaporate (that is, high vapor pressure), the metal powder is vaporized at a high temperature generated by electric discharge, and the metal vapor is mixed into the EDM fluid. There is a proposal to disperse and thereby reduce the pulse voltage to perform high-precision, high-stable, and high-speed electrical discharge machining (see Japanese Patent Publication No. 55-27810).

The high vapor pressure metals used there are cadmium, iridium, zinc, magnesium, tin, lead and bismuth. (5) 0.001 to 0.5 μm of semiconductor or conductor powder such as metal powder or graphite powder up to about 5 μm
Electric discharge machining with a powder mixed machining liquid mixed in 1% by volume to improve machining speed and reduce electrode wear,
There is a proposal to improve the surface of the work piece (Japanese Patent Laid-Open No. Sho 5)
(See Japanese Patent Laid-Open No. 5-500783).

According to this proposal, a work piece having a very uniform surface condition can be obtained (see JP-A-55-500783, page 4, upper right column, middle section). (6) In a machining fluid, electric discharge machining is performed with a machining fluid mixed with metal powder and water to which an organic substance consisting of a silicone-based surfactant, an alkyl ether-based surfactant or a mixture of any of them and oil is attached. There is a proposal to discharge the metal powder of No. 3, to carbonize the organic substance attached to the metal powder, and to attach the carbide to the electrode, thereby reducing the consumption of the electrode (see Japanese Patent Laid-Open No. 60-249527). . (7) Electric discharge machining is performed with a powder-mixed machining liquid containing a material forming the surface layer of the workpiece to be powdered, the powdered material is evaporated and dissolved, and the powdered material in the dissolved state is processed onto the surface of the workpiece. There is a proposal that the coating film of the powdery material is formed as a surface layer of the workpiece by colliding with the above at a high speed (see Japanese Patent Laid-Open No. 2-83119).

The proposal also states that it is also possible to impart an oscillating motion between the electrode and the workpiece to perform electric discharge machining to make the surface layer flat (see Japanese Patent Laid-Open No. 2-83119). .

In this proposal, a powder-mixed working liquid containing silicon having an average particle size of 20 to 40 microns at a concentration of 20 g / l (working oil) is specifically used. (8) Electric discharge machining is performed with a powder-mixed machining liquid containing a powder having an average particle size distribution of 5 to 10 microns to combine carbon of an electrode material and a powder material to refine a crystal structure of an electrode surface. Then, there is a proposal to thereby promote the discharge dispersion and make the discharge uniform (see Japanese Patent Laid-Open No. 3-277421).

A study on electric discharge machining using a powder-mixed machining fluid, which was announced in 1974 (Journal of the Institute of Electrical Processing VOL.
7, No. 14, P19 to 27), when electric discharge machining is performed by flowing an electric discharge machining liquid in which conductor particles (graphite is used) mixed in water, spark generation points are dispersed and conductor particles are dispersed. It has been observed that, in places where there are a lot of electric discharges, the frequency of occurrence of electric discharge increases and the processing accuracy of the work piece decreases.

Further, in order to obtain the shape accuracy and surface accuracy of the work piece, the concentration distribution of the conductor particles between the electrodes should be uniform,
It is stated that it includes the adoption of periodic lifting and lowering of electrodes.

[0011]

In the conventional proposals, techniques having completely different contents regarding the relationship between the characteristics of the powder-mixed working fluid and the working accuracy and the relationship between the working accuracy and the behavior of the powder in the working fluid are preferable. It is said that.

For example, powder (conductor particles) in the electric discharge machining liquid
That the particle size of the particles affects the improvement of the surface accuracy of the work piece (Japanese Patent Laid-Open No. 55-007883 and Japanese Patent Laid-Open No. 3-2).
In Japanese Patent No. 77421), the range of particle size contributing to the improvement of surface accuracy is different. Therefore, even if the powder particle size may contribute to the improvement of the surface accuracy, the range of the particle size that actually contributes to the improvement of the surface accuracy is not clear.

Further, it has been mentioned in the conventional proposals and research presentations that the electric discharge is generated by the powder in the electric discharge machining fluid and the electric discharge is dispersed.

However, when a metal powder that evaporates in electric discharge machining is mixed, a certain proposal (Japanese Patent Publication No. 55-2781).
No. 0), it is said that the surface accuracy of a workpiece is improved by lowering the pulse voltage by mixing and dispersing the metal vapor vaporized by high-temperature heating during electric discharge in the electric discharge machining liquid.

That is, the improvement of the processing accuracy is because the state of the voltage pulse changes due to the presence of the metal powder, and the surface of the workpiece is processed by the discharge of the changed voltage.

However, another proposal (JP-A-2-83119)
In Japanese Patent Laid-Open Publication No. 2003-242242), a swinging motion is applied between the electrode and the workpiece to prevent the powder materials vaporized by the electric discharge and dissolved in the electric discharge machining liquid from adhering to each other. This is because the film can be formed.

That is, the reason why the surface of the work piece becomes smooth is not because the work piece is smoothed by electric discharge, but the coating film of the melted powder material adheres to the surface of the work piece, and the adhered coating. The reason is that the film becomes smooth due to the swinging motion.

Therefore, it is said that the effect of the metal powder dissolved and evaporated in the electric discharge machining on the electric discharge machining is completely different according to the proposal, and the surface of the workpiece is also in a different state. The fact is that it is not clear what the surface of the workpiece will look like, even if the metal powder that dissolves and evaporates therein is mixed into the electric discharge machining liquid.

For this reason, the electric discharge machining technique for a workpiece with high machining accuracy using a powder-mixed machining liquid has a large number of unknown areas in fact, and industrial implementation using a powder-mixed machining liquid has many obstacles. was there.

Therefore, as a result of studying the dispersion of the powder in the powder, which is the basic property of the powder-mixed machining liquid, the present inventor has, in the process, powder-dispersed electric discharge machining in which the powder is dispersed under specific conditions. It has been experimentally found that the liquid significantly improves the surface accuracy of the workpiece, that is, smoothes it. Here, an object of the present invention is to provide a powder-concentrated dispersed liquid material that provides a powder-dispersed electric discharge machining liquid that improves machining accuracy.

Another object of the present invention is to provide a powder-dispersed electric discharge machining fluid which improves machining accuracy.

Furthermore, another aspect of the present invention provides an electric discharge machining method capable of remarkably smoothing the finished surface of a workpiece by performing finishing using the powder-dispersed electric discharge machining fluid of the present invention. That is the purpose.

[0023]

The powder-concentrated dispersion liquid material according to the present invention has the characteristics described in the following (1) and (2), and concentrates and disperses a powder for electric discharge machining into a liquid soluble in an electric discharge machining liquid. It is something that has been done. (1) The mixture of the powder and the soluble liquid can be kneaded, and (2) the mixture of the powder and the soluble liquid can be kneaded to form a powder concentrated dispersion liquid. Further, the powder-dispersed electric discharge machining liquid according to the present invention is characterized in that the powder-concentrated dispersion liquid material is dissolved in the electric discharge machining liquid to disperse the powder of the liquid material in the electric discharge machining liquid. Further, the electric discharge machining method according to the present invention is characterized by using the powder dispersion electric discharge machining liquid of the present invention for finishing. [Detailed Description of the Invention] Among the phenomena that the present inventor experimentally found about the behavior of the powder dispersed in the electric discharge machining fluid,
Some of the triggers of the present invention are as follows. (A) Discharge when using a powder-mixed machining fluid in which a metal powder that has been conventionally usable (including a conventionally proposed metal powder) and a base oil of an oil electric discharge machining fluid are stirred and mixed by a stirrer The gap widened and the machining accuracy became lower.

The same was true even if the stirring power of the stirring device was increased. (2) Even if the powder-mixed working fluid is a mixture of a conventionally usable metal powder (including a conventionally proposed metal powder) and a base oil of an oil discharge machining fluid, which is strongly stirred,
It was observed that the metal powder easily settled, and in the electric discharge machining, the powder-mixed machining fluid flowing between the electrode and the workpiece was in a state in which the powder was non-uniformly dispersed.

Moreover, in the powder-mixed working fluid in that state,
It has been found that if the surface of the work piece is smoothed, it is difficult to improve the working accuracy of the work piece even if the conventionally proposed metal powder is dispersed.

That is, a metal powder that has been conventionally usable for electric discharge machining (including a conventionally proposed metal powder).
It has been found that the conventional stirring means cannot obtain the powder-mixed working fluid which has been conventionally proposed to improve the working accuracy of the work piece.

Therefore, a metal powder is uniformly dispersed in a base liquid and a dispersing agent such as a conventionally proposed surfactant which is said to be effective for maintaining the dispersed state is used to prepare a powder dispersion processing liquid. Was prepared and tried to be electric discharge machined.

However, it has been found that some of the conventionally proposed surfactants cause the metal powder to agglomerate when added, and that the metal powder once agglomerated is extremely difficult to redisperse. Therefore, it has been found that the method of dispersing the metal powder with a surfactant is not a general method for dispersing the metal powder in industrial practice.

Therefore, the relationship between the dispersibility and dispersion stability of metal powders (including conventionally proposed metal powders) that can be used in electric discharge machining in an electric discharge machining liquid, and the relationship between dispersibility and improvement of machining accuracy. Was experimentally studied in detail by the present inventor.

By dissolving the powder concentrated dispersion liquid product of the present invention in the electric discharge machining liquid, the powder dispersion electric discharge machining liquid of the present invention having excellent dispersibility and dispersion stability can be obtained. It has been found in the present invention that the use of the dispersed electric discharge machining liquid improves the machining accuracy.

In the following description, the powder-concentrated dispersion liquid material of the present invention may be abbreviated as a liquid material as necessary, and the powder dispersion electric discharge machining liquid of the present invention may be abbreviated as a powder dispersion processing liquid. . <Liquid Material> The liquid material of the present invention is a powder in which a powder is microscopically uniformly dispersed in a liquid soluble in an electric discharge machining liquid in a concentrated state (that is, a high concentration).

The concentrated state is a state in which a remarkably large amount of powder is dispersed and contained as compared with the powder concentration of the powder dispersion processing liquid. Then, the powder concentrated dispersion liquid is
It is obtained by kneading the mixture by increasing the powder content so that a mixture of the powder and a liquid soluble in the electric discharge machining liquid can be kneaded. Powder Powder is a solid powder that is insoluble in an electric discharge machining liquid, and is typically a semiconductor or conductor metal powder.

The powder may be composed of only one kind, or may be composed of plural kinds.

Regarding the particle size or particle size distribution of the powder,
There are no particular restrictions.

However, if the particle size becomes too large, the electric discharge machining becomes unstable, or the electrodes are electrically short-circuited to damage the work piece. On the other hand, if the particle size is too small, the particles tend to condense with each other and settle out easily.
According to the finding of the present invention, it is possible to use even 1 μm or less.

However, if the surface of the particles is oxidized when the powder particles are crushed, the conductivity becomes poor.

Therefore, the particle size range of the powder particles is 1
It is preferably from 00 to 0.1 μm. In particular, when the powder particle size is such, the liquid material of the present invention is dissolved in an electric discharge machining fluid to prepare the powder dispersion machining fluid of the present invention, and the finished product is also processed by the finishing. It has been found in the present invention that the surface is particularly smooth.

Further, the electric discharge machining fluid is prepared by dissolving the liquid material of the present invention so as to have the same concentration as the powder concentration (about 1 to 2% by weight) of the conventional general powder-mixed machining fluid. However, it has been found in the present invention that the surface of the workpiece becomes smooth even by electric discharge machining with the powder dispersion machining liquid. Therefore, the powder-dispersed liquid product of the present invention can smooth the surface of a work piece even with a powder having a particle size or a molecular weight distribution, which has hitherto been considered unsuitable for smoothing the surface of a work piece. It is possible to provide a powder-dispersed electric discharge machining solution and an electric discharge machining method capable of Examples of powders that can be used in the powder-dispersed liquid material of the present invention are as follows.

Silicon, graphite, brass, tungsten, silver, cadmium, iridium, zinc, magnesium, tin, lead, and alloys of bismuth and silver with silver,
Powder such as an alloy of copper and tungsten.

However, silicon powder or a combination thereof is preferable. Kneading of Powder and Soluble Liquid The powder-dispersed liquid material of the present invention is obtained by kneading a powder and an electric discharge machining liquid-soluble liquid and mixture. The liquid soluble in the electric discharge machining liquid is a base liquid of the aqueous electric discharge machining liquid (particularly, a polyol compound, water or a mixture thereof) when the electric discharge machining liquid is an aqueous electric discharge machining liquid.

When the electric discharge machining fluid is an oil-based electric discharge machining fluid, it is an oil (in particular, a hydrocarbon or an organic compound mainly containing it) which is soluble in the base liquid of the oil-based electric discharge machining fluid.

However, the soluble liquid and the base liquid of the electric discharge machining liquid may be the same.

The solubility of the soluble liquid in the electric discharge machining liquid does not have to be unlimited in terms of quantity, and the powder dispersion machining liquid of the present invention (detailed later) is prepared to have a predetermined powder concentration. It is only necessary that it has a solubility capable of dissolving the powder-dispersed liquid substance amount necessary for the above.

The soluble liquid and the electric discharge machining liquid do not need to have the same viscosity at all, and it is preferable that the soluble liquid has a high viscosity. As the soluble liquid, a liquid derived from an aliphatic hydrocarbon, a liquid derived from an aromatic hydrocarbon, a mixture of both, or the like can be used. Further, they may be those obtained by decomposing natural resources (for example, petroleum) or may be synthetic ones. Among the soluble liquids, particularly preferable oils are oils mainly containing aromatic hydrocarbons. Further, among oils mainly containing aromatic hydrocarbons, high-density oils, for example, oils having a density of 0.93 g / ml (15 ° C) or more and a kinematic viscosity of 100 cSt (40 ° C) or more However, it weakens the binding force between solid powders, giving fluidity to liquids,
It is preferable because it prevents sedimentation.

Then, in the present invention, a mixture that can be kneaded is prepared from the powder and the soluble liquid, and the mixture is kneaded. That is, a mixture having a remarkably large powder content is prepared as compared with a conventional general powder-mixed working fluid.

The amount of powder in the case where the powder and the soluble liquid can be kneaded and mixed is influenced by both the properties of the powder and the properties of the soluble liquid, and therefore it is difficult to uniformly determine the amount.

For example, if the soluble liquid has a high viscosity, the mixture can be kneaded even if the powder amount is small. The term "mixture that can be kneaded" means that the fluidity of the mixture at room temperature can be kneaded. The powder properties that affect the fluidity of the mixture include the powder type, particle size, particle size distribution, and powder surface state.

The properties of the soluble liquid that affect the fluidity of the mixture include the viscosity and density of the soluble liquid and the solubility in the electric discharge machining liquid.

Although it is difficult to uniformly determine the amount of the powder that makes it possible to knead the mixture of the powder and the soluble liquid, it is about 10 to about 80% by weight (based on the total weight of the soluble liquid and the powder). Is.

The powder-dispersed liquid material of the present invention is "a mixture of powder and a soluble liquid can be kneaded" and "a powder and a soluble liquid are kneaded to form a powder-dispersed liquid material". Is characterized by the following reasons. (A) The powder-dispersed liquid material of the present invention is one in which the powder is microscopically uniformly dispersed in the soluble liquid by a shearing force, so that the mixture of the powder and the soluble liquid is in a kneaded state. Because it is necessary. (B) The powder amount of the mixture is determined for the mixture that can be kneaded. (C) This is because mixing by shearing force is essential for kneading.

Then, the mixture of the soluble liquid and the powder is
Knead with a device for kneading with general shearing force.

Apparatuses for kneading by shearing are known per se, and are often used in the fields of processing synthetic resins, manufacturing paints, papermaking, etc. For example, regarding those used for processing synthetic resins, , There are the following.

Rolls, kneaders, Banbury mixers and extruders.

These devices have a structure in which a synthetic resin is melted by heat and kneaded (synonymous with kneading) by a shearing action. It is desirable that the mixture of the soluble liquid and the powder in the present invention also has such a viscosity that it can be kneaded by these devices.

That is, in the present invention, there is no restriction on the means for kneading the mixture of the soluble liquid and the powder, but the powder-dispersed liquid material of the present invention is produced by the shearing action using these devices. Is desirable. Although these devices differ in magnitude of shearing force and the like, any of them can be used in the present invention. Of the illustrated devices, rolls are preferred.

When the mixture of the powder and the liquid which is soluble in the electric discharge machining liquid is kneaded by the shearing action, the powder is directly subjected to the shearing action and becomes a liquid substance which is microscopically uniformly dispersed in the soluble liquid.

Then, a shearing force is directly applied to the powder to microscopically uniformly disperse the powder in a liquid soluble in the electric discharge machining liquid (that is, the powder dispersion liquid material of the present invention). It has been found in the present invention that the surface of an object to be machined is remarkably smoothed when the powder dispersion machining liquid of the invention is dissolved in a liquid to prepare the powder dispersion machining liquid and the powder dispersion machining liquid is subjected to electric discharge machining. Powder-dispersed liquid material The powder-dispersed liquid material of the present invention is a material in which a mixture of a powder having a high content and a liquid soluble in an electric discharge machining liquid is kneaded by a shearing action, and the powder is microscopically uniformly dispersed in the liquid. Although the properties have changed from before kneading, they are liquid substances. The liquid material has a viscosity close to that of the electric discharge machining liquid, a liquid having a large viscosity and a non-Newtonian property, but has a fluidity. Note that, here, that the viscosity shows non-Newtonian property means that when the viscosity = S (shear stress) / γ (shear rate), the viscosity changes depending on the shear rate. <Powder Dispersion Machining Liquid> The powder dispersion machining liquid of the present invention is obtained by dissolving the powder dispersion liquid material of the present invention in an electric discharge machining liquid and dispersing the powder in the electric discharge machining liquid. Therefore, the "powder-dispersed electric discharge machining fluid" of the present invention is different from the conventional powder-mixed machining fluid in the method of dispersing the powder and the dispersion state.

The powder-dispersed working liquid may be prepared by dissolving the powder-dispersed liquid material according to the present invention in the electric discharge machining liquid so that the powder in the liquid has a predetermined concentration. In the conventional powder-mixed machining fluid, the powder concentration is set to several wt% (mostly 1-2 wt%), but in the powder-dispersed electric discharge machining fluid according to the present invention, even if the powder concentration is considerably smaller than that, It has been found in the present invention that the surface of the work piece can be made smooth.

Therefore, in the powder-dispersed electric discharge machining liquid according to the present invention, the powder concentration is not particularly limited. However, from the viewpoint of enjoying the effect of the powder-dispersed electric discharge machining liquid, 0.2 to 3% by weight (based on the weight of the electric discharge machining liquid) is particularly preferable.

The means for dissolving the powder-dispersed liquid material in the electric discharge machining liquid is not particularly limited, and a general stirring means may be used.

The electric discharge machining liquid for preparing the powder-dispersed machining liquid may be an aqueous electric discharge machining liquid or an oil-based electric discharge machining liquid. Additives such as a processing efficiency improver, a dispersant, an antioxidant and an antifoaming agent may be added to the powder dispersion processing liquid. These additives may be used alone or in combination.

Mineral oil is a typical base liquid for the oil-based electrical discharge machining liquid. <Electric Discharge Machining Method> The electric discharge machining method according to the present invention is an electric discharge machining method in which the powder dispersion electric discharge machining liquid of the present invention is used for finishing. In the electric discharge machining method of the present invention, as described above, the powder is uniformly dispersed in the electric discharge machining liquid microscopically, and the dispersion state is stable. No equipment required.

Further, in the electric discharge machining method of the present invention, the surface of the non-machined material can be remarkably smoothed even if the amount of powder is smaller than the amount conventionally required.

Furthermore, in the electric discharge machining method of the present invention, it has been found in the present invention that the surface of a work piece can be machined smoothly without using special electric discharge machining conditions.

Hereinafter, the present invention will be specifically described by way of examples, but the examples are merely examples and do not limit the present invention.

[0066]

【Example】

<Example 1> 500 g of mesh 600 silicon powder
Was gradually mixed with 500 g of mineral oil having a kinematic viscosity of 2 cSt (40 ° C.) over 1 hour with stirring.

The mixture was kneaded with two rollers having different rotation speeds until it became uniform. The kneaded product was a liquid substance having a grease-like fluidity. Part 2 of the liquid into a mineral oil-based hydrocarbon with a kinematic viscosity of 2 cSt (40 ° C)
An amount corresponding to wt% was added and stirred for 30 minutes to prepare a powder-dispersed oily electric discharge machining liquid. <Example 2> 500 g of mesh 600 silicon powder
A mineral oil-based hydrocarbon 500 having a kinematic viscosity of 32 cSt (40 ° C.)
g was gradually mixed with stirring over 1 hour.

The mixture was kneaded with two rollers having different rotation speeds until it became uniform. The kneaded product was a liquid substance having a grease-like fluidity. The liquid substance was added to mineral oil having a kinematic viscosity of 2 cSt (40 ° C.) in an amount corresponding to 2% by weight and stirred for 30 minutes to prepare a powder-dispersed oil-based electric discharge machining liquid. <Example 3> 500 g of a mixed powder of mesh No. 600 silicon powder and graphite was added to a kinematic viscosity of 480 cSt (4
(0 ° C.) mineral oil-based hydrocarbon (500 g) was added, and the mixture was gradually mixed with stirring for 1 hour.

The mixture was kneaded with two rollers having different rotation speeds until it became uniform. The kneaded product was a liquid substance having a grease-like fluidity.

The liquid substance was added to a mineral oil type hydrocarbon having a kinematic viscosity of 2 cSt (40 ° C.) in an amount corresponding to 2% by weight thereof and stirred for 30 minutes to prepare a powder-dispersed oil-based electric discharge machining liquid. Example 4 500 g of a mixed powder of No. 600 mesh silicon powder and graphite was added to a kinematic viscosity of 930 cSt (4
(0 ° C.) and 500 g of an aromatic hydrocarbon oil having a density of 0.98 g / ml (15 ° C.) and gradually mixed with stirring for 1 hour.

The mixture was kneaded with two rollers having different rotation speeds until it became uniform. The kneaded material was a liquid material having fluidity.

The liquid was added to mineral oil having a kinematic viscosity of 2 cSt (40 ° C.) in an amount corresponding to 2% by weight and stirred for 30 minutes to prepare a powder-dispersed electric discharge machining fluid oil-based electric discharge machining fluid. <Example 5> 500 g of a mixed powder of No. 600 mesh silicon powder and graphite was added to 500 g of dipropylene glycol, and the mixture was gradually mixed while stirring for 1 hour.

The mixture was kneaded with two rollers having different rotation speeds until it became uniform. The kneaded material was a liquid material having fluidity.

The liquid substance was added to a nonflammable electric discharge machining liquid having a kinematic viscosity of 6 cSt (40 ° C.) in an amount corresponding to 2% by weight, and the mixture was stirred for 30 minutes to obtain a powder dispersion electric discharge machining liquid nonflammable electric discharge machining liquid. Was prepared. <Example 6> 500 g of mixed powder of mesh No. 600 silicon powder and graphite powder and kinematic viscosity 930 cSt
(40 ° C.) and 500 g of an aromatic hydrocarbon oil having a density of 0.98 g / ml (15 ° C.) were gradually mixed with stirring for 1 hour.

The mixture was kneaded with two rollers having different rotation speeds until it became uniform. The kneaded material was a liquid material having fluidity. The liquid substance has a kinematic viscosity of 2 cS
An amount corresponding to 4% by weight of the t (40 ° C.) mineral oil was added and stirred for 30 minutes to prepare a powder-dispersed oil-based electrical discharge machining liquid. <Example 7> 500 g of mesh 600 silicon powder
And 20 g of the ethylene oxide-based colloidal dispersion were added to 500 g of polybutene having a kinematic viscosity of 450 cSt (40 ° C.) and gradually mixed with stirring for 1 hour.

The mixture was kneaded with two rollers having different rotation speeds until it became uniform. The kneaded material was a liquid material having low fluidity and was so-called semi-fluidity.

A liquid substance having the low fluidity is used as a kinematic viscosity 2
An amount corresponding to 1% by weight thereof was added to mineral oil of cSt (40 ° C.) and stirred for 30 minutes to prepare a powder-dispersed oil-based electric discharge machining liquid. <Embodiment 8> 500 g of mixed powder of No. 600 mesh silicon powder and graphite powder, 20 g of ethylene oxide colloidal dispersion, and a small amount of alkenyl succinimide dispersant while stirring for 1 hour with kinematic viscosity 930.
It was gradually mixed with 500 g of aromatic hydrocarbon oil having a cSt (40 ° C.) and a density of 0.98 g / ml (15 ° C.).

The mixture was kneaded with two rollers having different rotation speeds until it became uniform. The kneaded material was a liquid material having fluidity.

The liquid substance was added to mineral oil having a kinematic viscosity of 2 cSt (40 ° C.) in an amount corresponding to 4% by weight and stirred for 30 minutes to prepare a powder-dispersed oil-based electric discharge machining liquid. <Example 9> Silicon powder No. 600 mesh and 20 g of an ethylene oxide colloidal dispersion were used to obtain a kinematic viscosity of 3.2.
500 g of mineral oil of cSt (40 ° C.) was gradually mixed with stirring for 1 hour.

The mixture was kneaded with two rollers having different rotation speeds until it became uniform. The kneaded material was a liquid material having fluidity.

The liquid substance was added to mineral oil having a kinematic viscosity of 2 cSt (40 ° C.) in an amount corresponding to 4% by weight and stirred for 30 minutes to prepare a powder dispersion oil-based electric discharge machining liquid. <Example 10> An oil-based electrical discharge machining liquid was prepared only from the mineral oil having a kinematic viscosity of 2 cSt (40 ° C) used in Examples 1 to 4 and Examples 6 to 9. <Example 11> A commercially available oil-based electric discharge machining liquid was used. Next, electric discharge machining was performed using the electric discharge machining liquids prepared in Examples 1 to 11. The conditions of electric discharge machining were as shown below. EDM Conditions EDM Sodick A35 MARK21 Machining Electrode Copper (30mm × 30mm, 70mm ×
70 mm, 100 mm x 100 mm, 200 mm x 20
0 mm) Workpiece SKD-11 discharge conditions pulse width 4 μS, current (during short circuit) 5 A, polarity electrode (+) The obtained results are shown in Tables 1 and 2. Table 1 shows the time until the surface roughness becomes constant. In addition, Examples 1 to 11 in Table 1 show that the electric discharge machining liquids prepared in those Examples were used.

[0082]

[Table 1] Further, Table 2 shows the surface roughness of the workpiece which can be reached over a sufficient time using the electric discharge machining liquids prepared in Examples 1 to 11.

[0083]

[Table 2] According to the results shown in Table 1 and Table 2, Examples 1 to 1
By using the electric discharge machining liquid of No. 9, it is possible to reach a certain surface roughness in a remarkably short time, and it is possible to process a work piece having a remarkably smooth surface. In addition, FIG.
70 mm x 70 m using the electric discharge machining fluid of Example 8
It shows the measurement result of the surface roughness of the workpiece when the electrode of m is used. Moreover, FIG. 2 shows Example 10 of Table 2.
2 shows the results of measuring the surface roughness of a workpiece when using a 70 mm × 70 mm electrode using the electric discharge machining liquid of FIG.

[0084]

The object of the present invention is achieved. That is,
According to the powder concentrated dispersion liquid material of the present invention, it is possible to process a work piece having a desired surface roughness in an extremely short time, and
It is possible to provide a powder-dispersed electric discharge machining liquid capable of machining a work piece into a remarkably smooth surface. Further, according to the powder-dispersed electric discharge machining fluid of the present invention, it is possible to process a work piece having a desired surface roughness in a remarkably short time, and it is possible to process the work piece into a remarkably smooth surface. . Further, according to the electric discharge machining method of the present invention, it becomes possible to perform finish machining for machining a work piece into a remarkably smooth surface.

[Brief description of drawings]

FIG. 1 is a diagram showing the surface roughness of a workpiece.

FIG. 2 is a diagram showing a surface roughness of a workpiece.

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[Procedure amendment]

[Submission date] December 8, 1993

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

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[Claims]

Claims (6)

[Claims] 1. A powder-concentrated dispersion liquid material obtained by concentrating and dispersing a powder for electric discharge machining into a liquid soluble in an electric discharge machining liquid, which has the characteristics described in (1) and (2) below. (1) The mixture of the powder and the soluble liquid can be kneaded, and (2) the powder and the soluble liquid can be kneaded to form a powder concentrated dispersion liquid. 2. A powder-concentrated dispersion liquid product obtained by concentrating and dispersing a powder for electric discharge machining in a liquid soluble in an electric discharge machining liquid, which has the characteristics described in (1) and (2) below. And a powder-dispersed electric discharge machining liquid in which powder of the liquid material is dispersed in the electric discharge machining liquid. (1) The mixture of the powder and the soluble liquid can be kneaded, and (2) the mixture of the powder and the soluble liquid can be kneaded to form a powder concentrated dispersion liquid. 3. A powder-concentrated dispersion liquid obtained by concentrating and dispersing a powder for electric discharge machining into a liquid soluble in the electric discharge machining liquid, which has the characteristics described in (1) and (2) below after being electric discharge machined with the electric discharge machining liquid. An electric discharge machining method, characterized in that a material is dissolved in the electric discharge machining liquid, and a powder dispersion electric discharge machining liquid obtained by dispersing powder of the liquid material in the electric discharge machining liquid is used for finishing. (1) The mixture of the powder and the soluble liquid can be kneaded, and (2) the mixture of the powder and the soluble liquid can be kneaded to form a powder concentrated dispersion liquid. 4. The powder concentrated dispersion liquid product according to claim 1 or the electric discharge machining liquid according to claim 2, wherein the powder is a conductive or semiconductive metal powder. 5. The soluble liquid has an oil containing hydrocarbon as a main component or an aromatic hydrocarbon having a density of about 0.93.
3. The powder concentrated dispersion liquid product according to claim 1 or the electric discharge machining liquid according to claim 2, which is a high-density oil of g / ml (15 ° C.) or higher. 6. The mixture is a mixture of 10 to 80% by weight of a conductive or semiconductive metal powder (based on the total weight of the metal powder and a soluble liquid) and a soluble liquid. The powder concentrated dispersion liquid product according to claim 1 or the electric discharge machining liquid according to claim 2.