JP4041858B2 - Composite polishing method and abrasive polishing apparatus for cemented carbide electrical discharge machining surface - Google Patents

Description

  The present invention relates to polishing of an electric discharge machined surface of a cemented carbide used for various nozzles such as high-pressure injection and chemical nozzles.

  At present, cemented carbides having excellent wear resistance and heat resistance are widely used in various applications in addition to various nozzles such as high-pressure injection and synthetic fiber nozzles.

  Here, since the cemented carbide is extremely hard with a Vickers hardness HV of about 1400, it is difficult to process using a cutting tool such as cutting, and electric discharge machining is generally used mainly for machining cemented carbide. .

  However, when EDM is performed on cemented carbide, depending on the processing conditions, surface defects such as cracks and microholes are formed on the processed surface, and this surface defect is a major factor that significantly reduces the material strength, shortening the product life. ing.

  Therefore, it is desirable to remove surface defects as much as possible. However, since cemented carbide is very hard, it is very difficult to remove all surface defects only by conventional mechanical polishing. When polishing the processed surface of the hole, the shape is also complicated, and polishing the inner surface of the nozzle hole becomes even more difficult, so the development of a good polishing method that completely removes surface defects on the electric discharge processed surface is strongly desired. It is rare.

  The present invention has been completed in view of the above problems. For example, in a hard hole made of cemented carbide, such as a nozzle made of cemented carbide, which is not only very hard but also has a complicated shape and is very fine and difficult to polish. By applying a completely new combined polishing method that combines surface modification using phenomenon and polishing with fluidized abrasive grains, the surface integrity without surface defects is maintained while maintaining the shape after wire EDM. It is an object of the present invention to provide an epoch-making composite polishing method capable of finishing an excellent electric discharge machining surface made of cemented carbide.

  The gist of the present invention will be described with reference to the accompanying drawings.

A method of polishing a cemented carbide electro-discharge machined surface 1 formed by wire electric discharge machining, wherein the machined surface 1 is heated and held at a temperature of 620 ° C. or higher by high-frequency induction heating so that cobalt oxide and tungsten oxide are formed on the machined surface 1. And an oxide layer 2 composed of a composite oxide of tungsten and cobalt is formed from the surface to the inside, and abrasive grains 3 are brought into contact with the oxide layer 2 to completely form the oxide layer 2 from the processed surface 1. The present invention relates to a composite polishing method for a cemented carbide electric discharge machined surface that is peeled off.

  The cemented carbide formed by wire electric discharge machining according to claim 1, wherein the machined surface 1 is a hole inner surface 5a of a cemented carbide fine hole 5 formed in the cemented carbide 4 by wire electric discharge machining. The present invention relates to a composite polishing method for an alloy electric discharge machining surface.

  Further, the abrasive grains 3 were forced to flow from the openings 6 of the fine holes 5, and the fluidized abrasive grains 3a were brought into contact with the hole inner surface 5a which is the processed surface 1 to form the hole inner surface 5a. 3. The composite polishing method for a cemented carbide electric discharge machined surface formed by wire electric discharge machining according to claim 2, wherein the oxide layer 2 is peeled off.

  Further, the abrasive grains 3 are forcibly distributed alternately from one end to the other end and from the other end to the other end of the opening 6 at both ends of the fine hole 5 and formed by wire electric discharge machining according to claim 3. The present invention relates to a composite polishing method for a cemented carbide electric discharge machined surface.

Further, the machined surface 1 is formed by wire electric discharge machining, and the machined surface 1 is heated and held at a temperature of 620 ° C. or higher by high-frequency induction heating, whereby cobalt oxide, tungsten oxide, and tungsten and cobalt are formed on the machined surface 1. A holding portion 9 for holding the cemented carbide 4 formed with the oxide layer 2 made of the composite oxide from the surface toward the inside, and abrasive grains on the processed surface 1 of the cemented carbide 4 held by the holding portion 9 3 is provided, and the abrasive grains 3 are brought into contact with the processed surface 1 on which the oxide layer 2 is formed by the abrasive contact means 10. The present invention relates to an abrasive polishing apparatus for a cemented carbide electro-discharge machined surface, which is configured to peel.

Further, the processed surface 1 is a hole inner surface 6 of a micro hole 5 made of cemented carbide formed on the cemented carbide 4 by wire electric discharge machining, and the holding for holding the cemented carbide 4 obtained by oxidizing the inner surface 6 of the hole. The tool 9 and abrasive contact means 10 for forcibly flowing the abrasive grains 3 from the openings 6 of the fine holes 5 of the cemented carbide 4 held by the holder 9 are provided. The abrasive grains 3 are forced to flow from the openings 6 of the fine holes 5 so that the fluidized abrasive grains 3 a are brought into contact with the hole inner surface 6 as the processing surface 1 to peel off the oxide layer 2 formed on the hole inner surface 6. The present invention relates to an abrasive polishing apparatus for a cemented carbide electric discharge machined surface according to claim 5 .

  Further, as the abrasive contact means 10, an abrasive distribution part 11 through which the abrasive grains 3 can be distributed through the openings 6 at both ends of the fine hole 5 is provided with one end connected to the opening 6. An abrasive grain storage part 12 that stores the abrasive grains 3 is connected to the other end of the circulation part 11, and the abrasive grains 3 that are stored in the abrasive grain storage part 12 are provided via the abrasive grain circulation part 11. 7. The abrasive polishing apparatus for a cemented carbide electric discharge machined surface according to claim 6, wherein the opening 6 of the hole 5 is configured to alternately flow from one end to the other end and from the other end to the other end alternately. It is.

  Since the present invention is configured as described above, it is difficult to polish, a cemented carbide electric discharge machining surface formed by wire electric discharge machining, by a composite polishing that combines a surface modification method by oxidation treatment and polishing with abrasive grains, Even if the surface of the cemented carbide has been extremely difficult to remove all surface defects by simply mechanical polishing, it can be finished to a surface with excellent surface integrity with no surface defects. In addition, it is excellent in workability because it can be polished well in a short time, and surface defects can be removed while maintaining the processed surface after wire electric discharge machining with high shape accuracy. It can penetrate into narrow gaps and holes well, reliably contact with the oxidized layer formed on the processed surface, and peel off the oxidized layer, so it can be applied to processed surfaces of various shapes and is extremely practical. Integrated polishing method for a cemented carbide EDM surface and thus to provide a.

  In addition, for example, when the processed surface is made of a cemented carbide fine hole made of cemented carbide by wire electric discharge machining, the shape is complicated and it is extremely difficult to remove all surface defects with the conventional polishing method. Even in difficult fine holes, the excellent practicality of the present invention can be further clarified by polishing very well and finishing to a processed surface with excellent surface integrity without any surface defects.

  Further, for example, when the abrasive grains are forced to flow from the opening of the fine hole, the fine holes are simply forced to flow from only one end side of the opening of the fine hole. As for the inner surface of the hole, the inflow end side into which the abrasive grains flow is more consumed by the abrasive polishing than the outflow end side, and the loss of shape accuracy of the inner surface of the hole tends to be shifted toward the inflow end side. By forcibly flowing the abrasive grains through the openings at both ends of the hole, even after the oxide layer is completely removed from within the fine hole, the loss of shape accuracy of the inner surface of the hole is substantially uniform without shifting to the one end side. In addition, since the oxide layer is removed not only from one end but from both ends, the removal of all oxide layers can be completed efficiently in a short time, and high shape accuracy can be maintained, further improving workability. In addition, a composite of super hard metal EDM with excellent practicality And thus to provide a polishing method.

  Further, for example, when the abrasive grains are forced to flow alternately from one end to the other end of the opening of both ends of the fine hole and from the other end to one end, the oxide layer is completely removed from the inner surface of the fine hole. This makes it possible to keep the shape accuracy of the inner surface of the fine holes more uniform, remove the oxide layer more efficiently and in a shorter time, and make the composite polishing of the cemented carbide electrical discharge machined surface more excellent in workability and practicality A method will be provided.

  Since the present invention is configured as described above, it is possible to finish a cemented carbide electro-discharge machined surface formed by wire electric discharge machining, which is extremely difficult to polish, into a machined surface excellent in surface integrity without any surface defects. In addition to being possible, it can handle various shapes of machining surfaces, and can be polished efficiently while maintaining high shape accuracy after wire electric discharge machining efficiently and in a short time. Thus, a ground-breaking cemented carbide fine hole composite polishing method and composite polishing apparatus are provided.

  Embodiments of the present invention that are considered suitable (how to carry out the invention) will be briefly described with reference to the drawings, illustrating the operation of the present invention.

  An oxidation treatment is performed on the processed surface 1 formed by subjecting the cemented carbide 4 to wire electric discharge machining.

Specifically, the processed surface 1 is heated and held at a high temperature of 620 ° C. or higher by high frequency induction heating, and gradually begins to oxidize from the surface of the processed surface 1 toward the inside. A porous oxide layer 2 made of cobalt oxide, tungsten oxide, and a composite oxide of tungsten and cobalt and having excellent peelability is formed.

  When the abrasive grains 3 are brought into contact with the oxide layer 2, the oxide layer 2 is easily separated from the processed surface 1 while being pulverized by contact with the abrasive grains 3, and the oxidized layer is separated from the processed surface 1. By removing 2 completely, the finished surface 1 is excellent in surface integrity.

  Further, for example, when the processed surface 1 is the hole inner surface 5a of the cemented carbide fine hole 5, it is extremely difficult to satisfactorily polish the hole inner surface 5a only by the conventional mechanical polishing method. However, by forming the oxide layer 2 on the hole inner surface 5a of the fine hole 5 by an oxidation treatment and forcing the abrasive grains 3 to flow through the opening 6 of the fine hole 5, The fluidized abrasive grains 3 a that are the abrasive grains 3 penetrate into the fine holes 5, the abrasive grains 3 come into contact with the oxide layer 2 formed on the inner surface 6 of the fine holes 5, and the oxidized layer 2 is formed from the inner surface 6 of the holes. It will peel and will be finished in the processing surface 1 excellent in surface soundness.

  Therefore, the present invention is good for polishing not only the machined surface 1 of the cemented carbide 4 that is difficult to polish, but also the machined surface 1 that is extremely difficult to polish, such as the hole inner surface 5a of the fine hole 5. In addition to being able to finish the machined surface 1 with excellent surface integrity, it can be used on the machined surface 1 of various shapes, and it can be polished in a shorter time than before, so it has excellent workability. Thus, the composite polishing method and the abrasive polishing apparatus for the super-hard alloy electric discharge machined surface having excellent practicality are obtained.

  Specific embodiments of the present invention will be described with reference to the drawings.

  In this embodiment, a machined surface 1 is formed by wire electric discharge machining, and the machined surface 1 is heated and oxidized to hold the cemented carbide 4 formed with the oxide layer 2, and the holder 9 Abrasive grain contact means 10 for bringing the abrasive grains 3 into contact with the processed surface 1 of the cemented carbide 4 held on the surface is provided, and the abrasive grains 3 are formed on the processed surface 1 on which the oxide layer 2 is formed by the abrasive grain contact means 10. Is an abrasive polishing apparatus for a cemented carbide electric discharge machined surface configured to peel the oxide layer 2 from the machined surface 1 by bringing them into contact with each other.

  In the present embodiment, the processed surface 1 is a hole inner surface 5a of a cemented carbide cross-shaped fine hole 5, such as a cemented carbide nozzle used as a chemical fiber nozzle, as shown in FIG.

  The cemented carbide 4 is a cemented carbide D20 (JIS standard V type).

  The configuration of this example will be described in detail. As shown in FIG. 1, a holding part 9 constituted by a holding tool 9a for holding the cemented carbide 4 in a sandwiched state, the solvent 7 (deionized water), and An abrasive grain storage section 12 having a configuration in which an abrasive grain container 12a for storing the abrasive grains 3 (green carborundum) is provided in the openings 6 at both ends of the fine holes 5 of the cemented carbide 4 held in the holder 9a. And an abrasive container 12a provided at one end of the opening 6 and one end of the opening 6, and an abrasive container 12a provided at the other end of the opening 6 and the other end of the opening 6 are watertight. In the piston pump 14, there is an abrasive flow part 11 composed of an abrasive tube 11 a as a connection tool connected to the state, a piston pump 14 provided in each of the abrasive containers 12 a provided at both ends of the opening 6, and the piston pump 14. Cylinder 13 to be fitted and one side of this cylinder 13 is a gap portion 14b and the other side is a container portion 14a. The container 14a is filled with the solvent 7 and can absorb and drain the solvent 7. The solvent as a connector for connecting the container 14a of the piston pump 14 and the abrasive container 12a in a watertight state. A tube 15, a filter portion 16 provided at an end of the solvent tube 15 on the side connected to the abrasive container 12 a and configured to prevent the abrasive particles 3 from entering the piston pump 14, and the piston pump 14 Compressed air is sent to the air gap portion 14b, and an air compressor 17 that pressurizes the cylinder 13 fitted in the piston pump 14 and an air supply pipe 18 that connects the air compressor 17 and the air gap portion 14b of the piston pump 14 are connected. The compressed air of the air compressor 17 provided at a predetermined position of the air compressor 17 or the air supply pipe 18 is adjusted to a constant pressure, and the air supply direction is switched from one piston pump 14 to the other piston pump 14. It is constituted by a control device 19 capable of changing control.

  In this embodiment, green carborundum is used as the abrasive grain 3, and the cost is much lower than the diamond abrasive grain generally used as an abrasive for the cemented carbide 4. On the other hand, green carborundum is an abrasive that has a hardness that is generally high enough to be used for processing cemented carbide, and that can satisfactorily grind cemented carbide.

  Moreover, deionized water is adopted as the solvent 7, and it is not only extremely difficult to corrode compared with the case of using other solvents such as tap water, but also is easy to purify and handle, making it practical. It is excellent.

  Further, since the abrasive container 12a is made of stainless steel, and the abrasive tube 11a and the solvent tube 15 are made of urethane tubes, the apparatus is excellent in pressure resistance and durability.

  Further, the control device 19 not only can adjust the compressed air from the air compressor 17 to a constant pressure and control the switching of the air feeding direction, but also counts the number of times the air feeding direction is switched, the compression function A function for measuring the air flow rate and a function for adjusting the cycle time are provided, and it is excellent in practicality and can be appropriately set to various polishing conditions according to the shape of the processed surface 1.

  Next, in conjunction with the operation of the present embodiment, the composite polishing method of the cemented carbide electric discharge machining surface 1 by the composite polishing using the combination of the surface modification method using the oxidation phenomenon and the polishing by the abrasive grains 3 is used. The procedure will be described with reference to FIG.

  First, when wire electric discharge machining is performed on the cemented carbide 4, many surface defects 8 such as cracks and holes are formed on the machining surface 1 as shown in FIG. In the case of a brittle material, the strength is greatly reduced by this surface defect 8, and as a procedure of the composite polishing method for surface modification of this processed surface 1 to a processed surface 1 having no surface defects 8 and excellent surface integrity, First, the processed surface 1 is heated and oxidized.

  Then, the processed surface 1 is gradually oxidized from the surface, and an oxide layer 2 is gradually formed on the processed surface 1.

  Specifically, the processed surface 1 is heated by high frequency induction heating.

  This high-frequency induction heating is capable of heating in a short time compared to other heating methods such as an electric furnace, and also has a skin effect of generating heat from the surface, and is intended for heat oxidation treatment of the surface layer In this case, the heating method can be efficiently heated from the surface and oxidized in a short time, and has excellent efficiency and practicality.

  Thus, when the processed surface 1 is heated to a high temperature of 620 ° C. or higher by high-frequency induction heating, the processed surface 1 first reaches about 400 ° C. or higher, and cobalt oxide having low adhesion begins to be formed on the processed surface 1. Next, when the processed surface 1 reaches about 620 ° C. or more, in addition to the cobalt oxide, three types of oxides of tungsten oxide and a composite oxide of tungsten and cobalt are substantially uniform in the normal direction from the surface to the inside. It will be formed with an appropriate thickness.

  The oxide layer 2 composed of these three kinds of oxides is porous, and the cobalt oxide formed on the processed surface 1 gradually from the time when the processed surface 1 has already been heated to a temperature of 400 ° C. or higher. Because of its weak nature, it has excellent peelability.

  Therefore, by holding the processed surface 1 at a temperature of 620 ° C. or higher by the high frequency induction heating, the processed surface 1 is not only efficiently heated and oxidized from the surface within a short time, but also this processed surface 1 The oxide layer 2 formed on the surface 1 has a substantially uniform thickness in the normal direction from the surface, and is formed with an oxide layer 2 that can be easily peeled and removed because it is porous and excellent in peelability. It becomes.

  At this time, since the oxide layer 2 is formed while including the surface defects 8 formed on the processed surface 1, the oxide layers are formed on the processed surface 1 as shown in FIG. The processed surface 1 is heated and held until a formation thickness containing all 8 is reached.

  By this high-frequency induction heating, the cemented carbide 4 in which the oxide layer 2 is formed on the inner surface 5a of the fine hole 5 is held in the holding state by the holding tool 9a of the holding portion 9 of this embodiment.

  In this state, when compressed air is supplied to the gap portion 14b of one piston pump 14 of the piston pumps 14 through the air feeding pipe 18 by the air compressor 17, the air is fitted into the piston pump 14 by air pressure. The installed cylinder 13 is pressure-operated, slides in the piston pump 14 in the direction of the container part 14a, forcibly discharges the solvent 7 stored in the container part 14a of the piston pump 14, and this forced discharge The solvent 7 is forced to flow into the abrasive container 12 a connected to the container portion 14 a of the piston pump 14 through the solvent tube 15.

  As a result, a flow is generated in the abrasive container 12a, and the solvent 7 and the abrasive grains 3 stored in the abrasive container 12a are mixed by the flow to generate a fluidized abrasive grain 3a in a slurry state. The grains 3a are forcibly discharged from the abrasive container 12a and are forced to flow in from the opening 6 at one end of the micro hole 5 of the cemented carbide 4 held by the holder 9a through the abrasive tube 11a. The abrasive grains 3 suspended in the fluidized abrasive grains 3a come into contact with the oxide layer 2 formed on the hole inner surface 5a of the hole 5, and the oxide layer 2 is peeled from the hole inner surface 5a as shown in FIG. 3c.

  As described above, in this embodiment, the abrasive grains 3 are the thriller-shaped fluidized abrasive grains 3a mixed with the solvent 7 in the abrasive grain container 12a. Therefore, the flow of the abrasive grains 3 is simply flowed. Compared with the abrasive grains 3a, the flow resistance is small and the flowability is extremely increased, so that it can be easily forced to flow into the cross-shaped fine hole 5 having a relatively complicated shape via air pressure. In addition, the present invention is not limited to the cross-shaped hole shape of the fine hole 5 of the present embodiment, and can be forced to flow into the fine hole 5 having various shapes, so that the hole inner surface 5a of the fine hole 5 having various shapes can be formed. It is extremely practical for polishing.

  Further, the abrasive grains 3 stored in the abrasive container 12a are precipitated in the abrasive container 12a and stored in a laminated state at the bottom, so that it is difficult to be suspended well with the solvent 7. In this embodiment, the end of the abrasive tube 11a on the side connected to the abrasive container 12a is the inside of a stack of abrasive grains 3 formed by precipitation of the abrasive grains 3 at the bottom of the abrasive container 12a. In this state, the abrasive grains 3 can flow into the abrasive tube 11a well, and the thriller-shaped fluid abrasive grains 3a are composed of the solvent 7 and the abrasive grains 3. Is suspended and the fluidized abrasive grains 3a in which the abrasive grains 3 are suspended at a higher concentration are obtained, and thus the polishing performance is excellent.

  The flowing abrasive grains 3a forcedly flowed from one end of the opening 6 at both ends of the fine hole 5 polish the hole inner surface 5a of the fine hole 5, and are forcibly discharged from the other end of the opening 6. The abrasive container 11a is forced to flow into the abrasive container 12a connected to the other end of the opening 6 through the abrasive tube 11a, and the abrasive container from the abrasive container 12a through the solvent tube 15. The solvent 7 is forced to flow into the container portion 14a of the piston pump 14 connected to 12a.

  Here, the filter section 16 provided at the end of the solvent tube 15 on the side connected to the abrasive container 12a is configured by a filter that allows the solvent 7 to pass therethrough and prevents the abrasive grains 3 from passing therethrough. is there.

  Therefore, in the present embodiment, when the solvent 7 is forcibly discharged from the abrasive container 12a and the solvent 7 is forced to flow into the container portion 14a of the piston pump 14 via the solvent tube 15, this filter portion 16 is used. This prevents the abrasive grains 3 from entering the container portion 14 a of the piston pump 14. The abrasive grains 3 enter the container portion 14 a of the piston pump 14, and the piston pump 14 is polished by the abrasive particles 3. Therefore, the structure is extremely excellent in durability.

  In addition, since the filter part 16 should just be the structure which prevents the said abrasive grain 3 invading into the container part 14a of the said piston pump 14, it is not restricted to the structure of a present Example, For example, this container part 14a and the said The solvent container may be connected in a watertight state to a predetermined position of the solvent tube 15 for connecting the abrasive container 12a, and the solvent container may be provided in an interposed state between the container part 14a and the abrasive container 12a. In this case, the flowing abrasive grains 3a discharged from the abrasive container 12a forcibly flow into the solvent container connected to a predetermined position of the solvent tube 15 via the solvent tube 15, and the abrasive particles 3 are in the solvent container. Since only the solvent 7 is satisfactorily discharged from the solvent container and forced into the container part 14a of the piston pump 14 via the solvent tube 15, the abrasive container allows the abrasive grains to 3 prevents the intrusion into the container part 14a. It is.

  The solvent 7 forcibly flows into the container portion 14a of the piston pump 14 fills the container portion 14a of the piston pump 14 with the solvent 7, and the water pressure causes the cylinder 13 that is recessed in the Poston pump 14 to move. The piston pump 14 is slid in the gap 14b side direction.

  Next, the control device 19 switches the air supply direction of the air compressor 17 to the piston pump 14 on the reverse side, and the compressed air is sent to the piston pump 14 in which the solvent 7 is forcibly introduced and the container portion 14a is filled with the solvent 7. As a result, the solvent 7 in the abrasive polishing apparatus of the present embodiment is caused to flow backward to the fine holes 5 from the opposite direction, that is, from the other ends of the openings 6 at both ends of the fine holes 5. 3a is forced to flow in.

  In this way, by sending compressed air to one of the piston pumps 14, the solvent 7 and the fluidized abrasive grains 3 a are caused to flow through the air pressure to cause one end of the fine hole 5. The fluidized abrasive grains 3a are forcibly introduced from the opening 6 and then the compressed air is supplied to the other piston pumps 14 of the piston pumps 14, so that the solvent 7 and the fluidized abrasive grains are transmitted via the air pressure. The operation for forcibly flowing the flowing abrasive grains 3a from the opening 6 at the other end of the fine hole 5 by reversing the flow 3a is repeated by switching the air feeding direction of the air compressor 17 by the control device 19.

  In other words, in the present embodiment, the fluidized abrasive grains 3a are repeatedly passed at high speed from one end to the other end of the opening 6 at both ends of the fine hole 5 and from the other end to the one end, so that the hole of the fine hole 5 is obtained. The polishing of the inner surface 5a proceeds, and the oxide layer 2 formed on the hole inner surface 5a is gradually peeled off from the hole inner surface 5a.

  At this time, as described above, the oxide layer 2 is formed to a thickness that includes all the surface defects 8 formed in the hole inner surface 5a.

  Therefore, in this embodiment, the oxide layer 2 is completely removed from the fine holes 5 by the fluidized abrasive grains 3 a, and at the same time, all surface defects 8 contained in the oxide layer 2 are also removed from the fine holes 5. The hole inner surface 5a of the micro hole 5 of the cemented carbide 4 which is extremely difficult to polish by removing the oxide layer 2 is completely removed, as shown in FIG. This is an extremely practical composite polishing method capable of finishing the processed surface 1 with excellent soundness.

  Furthermore, in this embodiment, the flowing abrasive grains 3a are forced to flow from the opening 6 at the end of the fine hole 5, so that the flowing abrasive grains 3a flow into the oxide layer 2 formed on the hole inner surface 5a. The oxide layer 2 is gradually completely removed from the inflow end portion side, and the oxide layer 3 is earliest before the oxide layer 2 is completely removed on all the surfaces in the hole inner surface 5a. The end portion side of the hole inner surface 5a is removed by the abrasive grains 3 until the entire oxide layer 2 of the hole inner surface 5a is completely removed, and the surface shape is consumed as much as the shape accuracy. Will be damaged.

  However, in this embodiment, as compared with the case where the abrasive grains 3 are simply forced to flow in from the opening 6 on one end side, they are forced to flow in alternately from the openings 6 on both ends. The oxide layer 2 can be efficiently removed not only from both ends, but the entire oxide layer 2 on the hole inner surface 5a can be removed in a short time. The hole inner surface 5a has a shape with high shape accuracy after electric discharge machining. The oxide layer 2 is completely removed from the hole inner surface 5a while maintaining a substantially uniform shape accuracy in the hole inner surface 5a without being deviated only to one end side while maintaining the shape. .

  Therefore, since the present embodiment is configured as described above, the surface of the cemented carbide which is extremely difficult to polish and formed by wire electric discharge machining is excellent in surface integrity with no surface defects. In addition to being able to finish, it is possible to handle various shapes of processed surfaces, and it can efficiently polish in a short time while maintaining high shape accuracy of the shape after wire electric discharge machining, Furthermore, it is excellent in durability and pressure resistance, and it becomes a revolutionary cemented carbide electro-discharge machined surface polishing machine with excellent practicality.

  Note that the present invention is not limited to this embodiment, and the specific configuration of each component can be designed as appropriate.

It is a schematic explanatory drawing of the abrasive grain polishing apparatus of a present Example. It is a schematic explanatory drawing of the cemented carbide which concerns on a present Example. It is a schematic explanatory drawing of the procedure of the composite grinding | polishing method using a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processed surface 2 Oxidized layer 3 Abrasive grain 3a Fluidized abrasive grain 4 Cemented carbide 5 Fine hole 5a Hole inner surface 6 Opening part 9 Holding part
10 Abrasive contact means
11 Abrasive Distribution Department
12 Abrasive reservoir

Claims (7)

A method for polishing a cemented carbide electric discharge machining surface formed by wire electric discharge machining, wherein the machining surface is heated and held at a temperature of 620 ° C. or higher by high-frequency induction heating , and cobalt oxide, tungsten oxide, and An oxide layer made of a composite oxide of tungsten and cobalt is formed from the surface toward the inside, and abrasive particles are brought into contact with the oxide layer to completely peel the oxide layer from the processed surface. A composite polishing method for a hard alloy electric discharge machined surface.   2. The composite of a cemented carbide electric discharge machined surface formed by wire electric discharge machining according to claim 1, wherein the processed surface is a hole inner surface of a fine hole made of cemented carbide formed in the cemented carbide by wire electric discharge machining. Polishing method.   The abrasive grains are forced to flow from the openings of the fine holes, and the fluidized abrasive grains are brought into contact with the inner surface of the hole, which is the processing surface, to peel off the oxide layer formed on the inner surface of the hole. A composite polishing method for a cemented carbide electric discharge machined surface formed by wire electric discharge machining according to claim 2.   The cemented carbide electric discharge machining formed by wire electric discharge machining according to claim 3, wherein the abrasive grains are alternately forced to flow from one end to the other end and from the other end to the other end of the opening at both ends of the fine hole. Composite polishing method for surfaces. A processed surface is formed by wire electric discharge machining, and the processed surface is heated and held at a temperature of 620 ° C. or higher by high-frequency induction heating, so that the processed surface is made of cobalt oxide, tungsten oxide, and a composite oxide of tungsten and cobalt. provided a holding portion for holding the oxide layer the cemented carbide formed toward the inside from the surface made, the abrasive grains contacting means for contacting the abrasive on the processed surface of the cemented carbide and held to the holding portion The abrasive of the cemented carbide electric discharge machined surface is characterized in that the oxide layer is peeled off from the machined surface by bringing the abrasive grain into contact with the machined surface on which the oxide layer is formed by the abrasive grain contact means. Grain polishing equipment. The machined surface is an inner surface of a hard hole made of cemented carbide formed by wire electric discharge machining on a cemented carbide, the holder holding the cemented carbide obtained by oxidizing the inner surface of the hole, and the holder held by the holder Provided with an abrasive contact means for forcibly flowing abrasive grains from the opening of the fine hole of the cemented carbide, and forcing the abrasive grains to flow from the opening of the fine hole by the abrasive contact means. The abrasive polishing apparatus for a cemented carbide electric discharge machined surface according to claim 5 , wherein the oxide layer formed on the inner surface of the hole is peeled off by bringing the abrasive grains into contact with the inner surface of the hole as the processed surface. .   As the abrasive contact means, an abrasive circulation part through which the abrasive grains can circulate is provided in the openings at both ends of the fine hole with one end connected to the opening, and the abrasive is provided at the other end of the abrasive circulation part. An abrasive grain storage part for storing grains is connected and provided, and abrasive grains stored in the abrasive grain storage part are connected to one end from the other end and the other end of the opening of the fine hole via the abrasive circulation part. The abrasive polishing apparatus for a cemented carbide electric discharge machined surface according to claim 6, wherein the apparatus is configured to alternately and forcibly circulate.

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