JPS5971337A - Electrically conductive ceramic roll for electrical discharge machining apparatus - Google Patents

Abstract

PURPOSE:To provide an electrically conductive ceramic roll for electrical discharge machining apparatus, resistant to cracking and durable for the use for long period, by using an electrically conductive and heat-resistant ceramic roll as a cathode of an electrical discharge machining apparatus. CONSTITUTION:Powder of ceramics such as carbide, nitride, oxide, etc. is mixed with powder of metal such as iron, aluminum, etc., and the mixture is charged in a mold together with a rotary shaft and pressed with e.g. a hot press to obtain the objective electrically conductive ceramic roll having a heat resistant temperature of 900 deg.C. The roll is used as the cathode of an electrical discharge machining apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conductive ceramic roll for an electric discharge machining apparatus, in which a roll rotating through an organic polymer molded article is used as a conductive ceramic roll on the anode side of an electric discharge machining apparatus. be.

Generally, during the process of molding organic polymer molded products such as polyethylene films and vinyl films, electrical discharge machining equipment using high-pressure electrical discharge is used to roughen the surface of polyethylene films, and the anticathode of this electrical discharge machining equipment A rubber roll or a silicone coated roll is provided on the side with a polyethylene film layer interposed therebetween. The heat discharged from this electrical discharge machining device is absorbed by the rubber roll via the polyethylene film.

However, if this rubber roll is exposed to heat for a long period of time, cracks will occur and it will become unusable. Furthermore, if the electric discharge machining apparatus is used frequently, the incidence of cracks will further increase. This required interruption of the polyethylene film flow process, and also required considerable effort to replace the rubber rolls.

Therefore, the invention was invented to eliminate such drawbacks, and by using a conductive and heat-resistant ceramic roll instead of a rubber roll, it can be used for a long time without cracking. An object of the present invention is to provide a conductive ceramic roll for electric discharge machining that can withstand durability.

Hereinafter, the present invention will be explained with reference to FIGS. 1 to 3.

FIG. 1 is a perspective view showing an embodiment of a conductive ceramic roll for electrical discharge machining equipment according to the present invention.

In FIG. 1, the anode side of the discharge 7) D-processing device (not shown) is a ceramic roll 1 that is conductive and has a heat resistance temperature of 900°C, and this ceramic roll 1 is made of metal or non-metal. It is formed on the rotating shaft 2.

Such conductive ceramic rolls (hereinafter simply referred to as ceramic rolls) are made by mixing ceramic powders such as carbides, nitrides, and oxides with metal powders such as iron, copper, and aluminum, and molding them together with a rotating shaft 2 (not shown). ), and then placed in a mold or the like together with the rotary shaft 2, and formed by a normal sintering method or a method such as hot pressing.

For example, aluminum powder (A) is applied to zinc oxide (ZnO) powder.
, 1203), chromium oxide (Cr203), and lithium oxide (T, 120) are added, placed in a mold (not shown) together with the rotating shaft 2, and molded at room temperature and high pressure.The molded product is taken out of the mold and placed in a furnace. It is placed in a core tube (not shown) and fired at a high temperature, for example, about 400° C., to produce a ceramic roll. At this time, the electrical conductivity of the ceramic roll is determined by changing the amount of the above-mentioned materials added depending on the intended use of the ceramic roll.

In addition, although the electrical conductivity is not so high, it has a heat-resistant temperature, for example, 8
For ceramic rolls that require a temperature of about 00 to 900°C, a nickel oxide-thorium oxide powder containing several percent of thorium oxide (ThO2) fine particles mixed in nickel (Ni) is prepared and reduced at a temperature of about 900°C. The powder K of Ni'rho'2 is put into a mold together with the rotating shaft 2, and then fired.

As described above, the sintering temperature of the metal composite material to be fired is, for example, the temperature of about 900° C. for Ni-ThO2 mentioned above. If firing is performed at a temperature higher than this, the ceramic roll may become deformed or -! The precision of ceramic rolls decreases.

In other words, the ceramic roll of the present invention has a conductivity value that varies depending on the amount of additives depending on the purpose of use, and further changes the electrical conductivity value depending on the heat resistance temperature and degree of mechanical strength. The desired result can be obtained by adding titanium carbide (Tie) to increase the

Next, another example of such a ceramic roll will be described with reference to FIGS. 2 and 3.

FIG. 2 is a perspective view showing another embodiment of the conductive ceramic roll for electrical discharge machining equipment according to the present invention. The coating ceramic 4 is coated with a ceramic such as that described above or a similar ceramic by a sintering furnace (not shown) or a hot press (not shown).

FIG. 3 is a perspective view showing yet another embodiment of the conductive ceramic roll for electrical discharge machining equipment according to the invention, in which the roll 5 made of metal or non-metal has a protrusion on the outer periphery of the roll 5 as a rotation stopper. A portion having a shape 5a is provided. Further, on the outer circumferential portion of this roll 5, a ceramic made of the material described when explaining the material shown in FIG. 1 or a similar ceramic is placed in a mold and molded in a sintering furnace or hot press. , concave shape 6a
A ceramic fired body 6 having a ceramic body 6 is fitted to form a ceramic roll.

Here, since a high voltage of several thousand kilovolts or more is applied to the ceramic roll, the conductivity of the ceramic roll may be a value that makes silicon rubber having a thickness of, for example, about 5 mm conductive. The outer peripheral surface of the ceramic roll may be either a smooth surface or a well-rounded rough surface. Furthermore, the ceramic and additives to the ceramic to be formed into a ceramic roll may be any compound, such as ceramic and plastic, ceramic and rubber, ceramic and carbon fibers, and the like.

As explained above, according to the present invention, it can sufficiently withstand the heat generated during electrical discharge machining, and can be used as the anode side of an electrical discharge machining device. Furthermore, since the surface of the roll is made of ceramics, Less wear and tear on the outer surface.

Therefore, since the conductive ceramic roll for electrical discharge machining equipment according to the present invention is less likely to be damaged or worn out, it is preferable to use a polyethylene film.

It can be incorporated into the manufacturing process of vinyl films, etc., and there is almost no need to stop the flow process due to defects in ceramic rolls, so production capacity can be increased.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of a conductive ceramic roll for electrical discharge machining equipment according to the present invention, FIG. 2 is a perspective view showing another embodiment according to the present invention, and FIG. FIG. 7 is a perspective view showing yet another such embodiment. 1... Ceramic roll, 2... Rotating shaft, 3.5
. . . Roll made of metal or non-metal, 4. Coated ceramics, 6. Ceramic fired body. Patent Applicant 1) Kazuyuki Nakav: J/lff1 Figure 2 and Figure 3 Must be

Claims (1)

[Scope of Claims] (+1) A conductive ceramic roll for electrical discharge machining equipment, characterized in that the anode side of the electrical discharge machining equipment is made of a ceramic roll that is conductive and has a heat resistance temperature of 900°C. (2 ) Claim 1, characterized in that the anode side of the discharge power device is coated on the outer circumferential surface of a roll made of metal or non-metal with ceramics that is conductive and has a heat resistance temperature of 900°C. The conductive ceramic roll for electrical discharge machining equipment as described above. (3) The anode side of the electrical discharge machining equipment is electrically conductive, and
2. The conductive ceramic roll for electrical discharge machining equipment according to claim 1, wherein a ceramic having a heat resistance temperature of 900° C. is fitted onto the outer peripheral surface of a roll made of metal or non-metal.