KR20020024892A - Superbrasive tool and manufacturing method of it using Superbrasive stone for grinding of Brown tube pannel face - Google Patents

Abstract

PURPOSE: A super-abrasive stone, a super-abrasive tool, and a method for manufacturing the same are provided to prevent the loading phenomenon without using slurry while preventing the scratch. CONSTITUTION: A super-abrasive tool(100) comprises an abrasive stone(110) and a fixing member(120) for fixing the abrasive stone(110). A cylindrical member(140) is protruded from a lower portion of the abrasive stone(110). A powder formed on the cylindrical member(140) and a lower surface of the abrasive stone(110) is coupled with the fixing member(120) when the powder is sintered. An annular slot(130) is formed at a lower portion of the fixing member(120). An annular protrusion(141) is formed at a lower periphery of the cylindrical member(140). A powder of the abrasive stone(110) remaining on the annular protrusion(141) is coupled with the fixing member(120), so that a relative movement between the abrasive stone(110) and the fixing member(120) in the axial and radial directions is limited.

Description

Superbrasive tool and manufacturing method of it using Superbrasive stone for grinding of Brown tube pannel face}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grindstone for polishing a CRT panel face surface, and more particularly, a super abrasive material capable of rough polishing of a panel face surface without scratching the face surface while polishing without using a slurry. ) A grinding wheel and a super abrasive tool for polishing a CRT face face using such a grindstone, and a method of manufacturing such super abrasive tool.

Superabrasives include diamond and cubic boron nitride (CBN). Since these super abrasive particles are harder than abrasive grains such as alumina and silicon carbide, they are used to polish specific materials such as mold steel and glass.

In general, the abrasive grindstone is determined according to the particle size and hardness of the abrasive particles, the grade (grade), the structure of the structure (structure), and the appropriate abrasive particles and binders should be selected according to the type of work, and appropriate porosity is required. Shall be. When the bonding degree is weak, the consumption of grindstone is increased. On the contrary, when the bonding degree is too strong, the particles do not fall off during polishing, so that cutting is not performed and the work surface is damaged by friction with the work surface. In addition, if the porosity is too small or the grinding wheel does not occur, eye filling may occur. Therefore, in the manufacture of grindstones for the pannel face polishing of CRT, it is important to have abrasive particles, binders, and porosity having appropriate particle size and hardness.

The CRT consists of CRT panel glass constituting the image display portion and CRT funnel glass constituting the body thereof. Panel glass and funnel glass are filled by ingot into a mold and are formed by pressing. Since the image display part of the panel glass cannot obtain the desired high quality smooth surface only by molding by pressing, rough grinding by GARNET, intermediate polishing by PUMICE, and finishing by ROUGE LAP It is processed into smooth surface by polishing.

Conventionally, as described in Utility Model Application No. 86-6717 'Special Glass Polishing Garnet Net', a plurality of metal buttons are inserted into a rubber pad to manufacture a pad-type polishing tool for polishing a CRT surface, and a polishing tool Was brought into contact with the surface of the CRT and supplied to the surface of the CRT to be polished the abrasive material mixed with the garnet powder, and then subjected to rough polishing by rotating or reciprocating while pressing the pad polishing tool at a constant pressure. That is, polishing was performed by supplying a slurry (SLURRY) containing solid abrasive particles such as garnet in water between the glass surface and the polishing tool and moving relative to each other to finely cut the glass surface. In addition, Patent Application No. 1994-3230, 'Brown Tube Panel Surface Grinding Device' discloses a grinding wheel that can be polished without slurry by inserting a number of buttons formed using diamond powder as abrasive grains into a rubber pad. Grinding grit for polishing of CRT panel is insufficient due to the filling of the grindstone and scratch on the CRT panel face.

That is, the conventional grinding or polishing point for the CRT panel face surface polishing has the following problems.

First, a rough abrasive polishing tool in which a large number of metal buttons are inserted into a conventional rubber pad causes deep scratches on the glass surface of the CRT panel, and the generated scratches are not removed even after intermediate and finishing polishing, which causes product defects. . In addition, since slurry (SLURRY) containing solid abrasive particles such as garnet is used in water, the scattering of these powders contaminates the working environment, and a large amount of sewage is discharged, thereby causing problems of environmental pollution. If the worker inhales the powder, the worker's health is harmed. In addition, cost increases due to abrasives and sludge treatment facilities, thereby increasing the cost of manufacturing CRTs.

Second, in the case of using a polishing tool made by inserting a plurality of buttons formed by using conventional diamond as abrasive particles in a rubber pad, slurry is not used, so there is no problem of environmental pollution. The defective rate of the product is high.

The present invention is to solve the above-mentioned problems, the first object of the present invention is environmental pollution by the slurry (SLURRY) generated when the polishing operation using a conventional CRT face face grinding tool, scratches, The present invention is to provide a grinding wheel for polishing a CRT face face without using a slurry and without causing scratches without using a slurry.

A second object of the present invention is to provide an ultra-abrasive tool capable of effectively polishing the CRT panel surface using the abrasive grindstone described above. In other words, the super abrasive tool is composed of a grindstone part and a grindstone fixing member part for fixing the grindstone, so that the superabrasive tool is doubled to be used up to the bottom of the grindstone.

It is a third object of the present invention to provide a coupling structure for firmly joining a grindstone to a grindstone fixing member such that a grindstone portion of the dually configured tool does not fall off during polishing. That is, to increase the bonding area of the grindstone and the rock-fixing member, or to form a jaw at the coupling portion of the grindstone and the rock-fixing member so that the separation does not occur mechanically.

It is a fourth object of the present invention to provide a method of manufacturing the dually constructed superabrasive tool. Provided is a method for manufacturing a dual-structure super-abrasive tool by sintering molding by inserting a grinding wheel fixing member into a mold during sintering of grindstone.

The object of the present invention is a series of processes for achieving one object of the face surface polishing of the CRT panel, and the invention of the super abrasive material itself using the grindstone composition and the grindstone composition for the CRT face polishing and the method of manufacturing the super abrasive tool. These inventions are to be provided in their entirety within the scope of one invention.

1A is a perspective view of a superabrasive tool;

1B is a cross-sectional view of a superabrasive tool having a cylindrical groove formed in an axial direction in an upper cross section of a grindstone fixing member;

1C and 1D are cross-sectional views showing another embodiment of the abrasive grindstone of the super abrasive tool of the present invention;

1E is a cross sectional view of a conventional superabrasive tool;

Figure 2 is a graph of the grinding amount of the super abrasive tool against the sintering temperature and sintering pressure.

<Description of Symbols for Main Parts of Drawings>

100: super abrasive tool 110: super abrasive grinding stone

120: super abrasive material fixing member 130: annular groove

In order to solve the above problems, a grindstone composition for polishing a CRT panel face face, which is sintered and formed with an abrasive grain mixture containing diamond and cubic boron nitride (CBN) in a constant volume ratio and a metal binder composed of copper and tin. To provide. In addition, the abrasive grain composition of the above abrasive stone composition may be left as it is, but instead of a metal binder with a binder composed of iron oxide and resin, a CRT stone polishing surface may be configured.

When a mixture of diamond and CBN powder is used as a grindstone composition, there is less thermal expansion of the material to be processed after processing, less processing deterioration layer, and the processing accuracy is excellently improved. In addition, there is an advantage that the damage caused by the heat of the grindstone powder is reduced, and the life of the grindstone is long.

In the present invention, the abrasive grain mixture is composed of diamond powder and CBN powder, and the volume ratio of the two elements at the time of mixing is in the ratio of upper limit 8.5: 1.5 and lower limit 9.5: 0.5. It was confirmed that the grinding or grinding effect was remarkably different depending on the mixing ratio of diamond and CBN particles in the grindstone, and the present invention was completed based on these findings. In addition, it can be seen from Table 1 described in Example 1 that the volume ratio described above is the best condition for rough polishing of the CRT panel face surface. When the diamond content is 100%, the exposed diamond smoothly polishes the CRT face face initially, but as grinding progresses, the surface of the diamond particles gradually fills the surface, resulting in grinding efficiency. Will fall. Therefore, when CBN particles are more brittle than diamond particles, the CBN particles broken during grinding grind the surface of the abrasive grindstone to remove the glare and at the same time polish the grindstone surface to expose the diamond particles to smooth the polishing. Diamond Knob Hardness 8000kg / mm ² , CBN Knob Hardness 4500kg / mm ² .

However, when the amount of CBN particles to be mixed is too large beyond a certain amount of range, the CBN particles act as the main abrasives rather than diamonds, which results in particle dropping, resulting in lower grinding efficiency. Therefore, the proper mixing ratio of abrasive particles is one of the important points in the construction of the grindstone so as to prevent excessive consumption of snow filling or grindstone during polishing and to avoid the need for separate dressing during continuous polishing.

The CRT panel polishing tool is made of rubber or other materials, as described in the prior art Utility Model Application No. 86-6717 'Special Glass Abrasion Reinforced Garnet PET'. It is a tool used to grind the CRT panel by inserting it into the pad and installing it in the polishing machine. The shape of the polishing tool depends on the type of polishing machine and the polishing method such as using rotation or vibration. Depending on the machine and the grinding method used in the grinding work, a circular pad may be used as a grinding tool for LAP M / C, and a square pad may be used for an AGM (Aspheric Grinding M / C). have. The former general LAP M / C is polished by the rotation of the CRT panel and the polishing tool, and the latter A.G.M has a difference in polishing work by vibrating the CRT panel and the polishing tool, respectively.

In constituting the grindstone composition, the particle size and toughness index of the abrasive particles may be varied according to the desired polishing amount and surface roughness of the CRT panel face. In addition, the particle size and toughness may be differently selected depending on the type of binder and the shape of the face surface grinding tool of the CRT panel, that is, the polishing method according to the type of polishing machine.

In case that the binder is composed mainly of iron oxide and resin, and the shape of the grinding wheel is circular, diamond and CBN particles have a toughness index of 50-60 and a particle size of 75-90 µm to obtain an appropriate polishing amount and roughness. It is preferable to use.

When the shape of the grinding wheel is square, diamond and CBN particles can obtain the most appropriate polishing amount and roughness when the toughness index is 50-60 and the size is 30-38 μm. If the abrasive grains have a toughness of 60 or more, the particles are not broken properly and the blade is dull to maintain the proper polishing amount. If the abrasive grains are 50 or less, the cracking of the particles occurs too quickly, leading to eye filling by the abrasive particles. This is because the proper polishing amount cannot be maintained. In addition, when the size of the abrasive grains is more than 38㎛, the abrasiveness is good because the grain size is large, but the required roughness cannot be obtained due to the roughness of the surface, and when it is less than 30㎛, smooth surface is obtained and the roughness is good, but the polishing amount is not good. Polishing efficiency cannot be achieved.

In the case where the abrasive grains have the above characteristics, the components of the grinding composition are preferably composed of a phenol resin having a volume fraction of 10 to 15%, 1 to 1.5% of CBN and 10 to 30% of iron oxide.

In the case of polishing with a metal such as copper and tin as a binder and the shape of the polishing tool in a circular shape, diamond particles have a toughness of 50 to 60, a size of 75 to 90 μm, and CBN particles have a toughness of 40 to 50 Its size is 75 ~ 90㎛, volume fraction is 10-15% of diamond, CBN 1 ~ 1.5%, and the remainder is mixed with 38 ~ 45㎛ size copper and tin powder to be used as binder, but the volume fraction of copper is 70 It is most preferable at the polishing amount and roughness to be -80%. This is because when the toughness of the abrasive grain is 60 or more, the abrasive grain is not broken properly, so that the proper polishing amount cannot be obtained. In the case of 50 or less, on the contrary, the abrasive grain is easily broken, the eye filling phenomenon occurs, and the proper polishing amount cannot be obtained. . In addition, when the size of the particles is 90㎛ or more, polishing is performed with large particles, but the polishing property is improved, but the roughness cannot be obtained due to the roughness of the surface. Poor polishing efficiency

In the case of polishing by using metals such as copper and tin as the binders, and the shape of the polishing tool in the form of a square, diamond particles have a toughness of 50 to 60, a size of 30 to 38 μm, and CBN particles have a toughness of 40 It is -50 and the size is 30-38 micrometers, volume fraction is 10-15% of diamonds, CBN 1-1.5%, and the remainder is mixed with 38-45 micrometers of copper and tin powder, and used as a binder, but the volume of copper A grindstone composition having a fraction of 70 to 80% is most preferred in terms of polishing amount and roughness. This is because when the toughness of the diamond grains is 60 or more, the diamond grains are not broken properly, so that a proper polishing amount cannot be obtained. When the diamond grains have a toughness of 50 or less, the diamond grains are easily broken, and thus, an eye filling phenomenon occurs and an appropriate polishing amount cannot be obtained. . In addition, when the size of the diamond particles is 38㎛ or more, large diamond particles are polished, so the polishing property is good, but the roughness cannot be obtained due to the roughness of the surface. If the size is less than 30μ, the surface is smooth and the roughness is good, but the polishing amount is decreased. Proper polishing efficiency cannot be obtained.

As described above, in order to grind the face surface of the CRT panel with the grindstone composition according to the present invention, the grindstone is processed into a suitable form, and a plurality of super abrasive tools are made and fixed on a pad, and then installed in a polishing machine and suitable for CRT panels and grindstones. It is necessary to make relative movement while applying pressure. 1 shows an embodiment of a super abrasive tool that facilitates the fixing of a grindstone to a pad.

The superabrasive tool constituting the present invention is configured in a dual structure as shown in FIG. The super abrasive tool 100 is composed of a grinding grindstone 110 and a grindstone fixing member 120. An approximately cylindrical member 140 protrudes from the lower portion of the abrasive grindstone 110, and the cylindrical member 140 and the powder on the lower surface 160 of the grindstone 110 are sintered and molded, and the grinding wheel fixing member 120 is formed. In combination with the basic button release prevention structure of the present invention. The lower portion of the grindstone fixing member 120 is provided with an annular groove 130 so as to be firmly fixed to the polishing tool for polishing the CRT panel face surface. Furthermore, in FIG. 1B, an annular protrusion 141 is formed at the lower edge of the cylindrical member 140, and the abrasive grindstone powder present in the protrusion 141 is combined with the member 120. The relative movement in the axial and radial directions between the members 110 and 120 is more reliably prevented and the contact surfaces between the members are expanded, thus providing a strong fastening structure that withstands prolonged repeated polishing and desorption. In addition, the button drop prevention structure of the present invention in addition to forming the insertion protrusion 142 directly on the lower surface 160 of the abrasive paper 110, as shown in [c] of FIG. ] By forming the thread-shaped concave-convex portion 143 on the front outer peripheral surface of the cylindrical member 140 so that they can be combined with the grinding stone fixing member 120 can be realized a robust separation prevention structure. These coupling structures may be used alone, but for more secure coupling, for example, it is possible to use them in combination as in parallel with the fastening structure of [b] of FIG. 1 and [c] of FIG. . Conventionally, as shown in [e] of FIG. 1, it has a simple double coupling structure, so that the fastening between the grindstone and the fixing member is not complete. As a result, even if any one of hundreds of tips is dropped, it is treated as a defective product. In the field of the present invention, overcoming the deterioration of economic efficiency and efficiency due to the dropping of the tip has been a big problem. The grindstone fixing member of the present invention is manufactured by machining with mild steel and inserted into a mold during sintering molding to inject a grindstone powder into an upper section to produce a super abrasive tool.

Next, the process of manufacturing the above-described CRT tool for polishing the face of the CRT panel face will be described. The manufacturing process varies the temperature, pressure and time of sintering molding depending on the components of the binder.

First, the process of manufacturing a super abrasive tool having iron oxide and resin as a main component of a binder is as follows.

(A) Volume fraction of abrasive grain mixture mixed with diamond and Cubic Boron Nitride so that the volume ratio is 8.5: 1.5 as the upper limit and 9.5: 0.5 as the lower limit, 11-16.5% and volume fraction 10- First step to prepare a mixed powder for grinding stone by mixing the binder composed of phenol resin containing 30% iron oxide

(B) Second step of assembling the grindstone fixing member manufactured in the mold to fix the grindstone

(C) a third step of putting the mixed powder into the steel mold and sealing the upper part of the mold by using a carbon punch;

(D) a fourth step of hot forming the mixed powder at a pressure of 0.25-0.35 ton / cm ² and a temperature of 160-170 ° C in the mold inserted into the vacuum resistance furnace;

In the manufacturing process, if the iron oxide component of the binder is less than 10% by volume, the amount of iron oxide is too small, and the overall life is shortened. This will shorten. When the binder is composed mainly of iron oxide and resin, use a tool steel mold that can be reused for a long time because there is no risk of thermal deformation even if the mold is made of steel because the proper sintering temperature is 160 to 170 ° C.

The process for producing a superabrasive tool comprising copper and tin powder as the main components of the binder is as follows.

(A) Volume fractions of abrasive grain mixtures mixed with diamond and Cubic Boron Nitride so that the volume ratio is 8.5: 1.5 as the upper limit and 9.5: 0.5 as the lower limit, 11-16.5% and 38-45 ㎛ The first process consists of tin and copper having a particle size of and the volume percentage of copper is 20-30% and the binder is made of tin to prepare a mixed powder for the production of grindstone

(B) Second step of assembling the ground stone fixing member manufactured to fix the ground stone into the carbon mold

(C) a third step of putting the mixed powder into the carbon mold and sealing the upper part of the mold by using a carbon punch;

(D) a fourth step of hot forming the mixed powder into the vacuum resistance furnace at a pressure of 0.1-0.25 ton / cm ² and a temperature of 650-750 ° C.

The ultra-abrasive tool using the metal powder as a binder can obtain a high service life, although the polishing amount per unit time is lower than that of the iron oxide and the resin as the binder. This is because the bonding force of the metal binder is larger than that of the binder mainly composed of iron oxide and resin. In the case of using metal binders of copper and tin powder, carbon steel molds are used because the proper sintering temperature is 650 to 750 ° C., so ordinary steel molds are not suitable due to heat deformation.

Hereinafter, an embodiment of the above invention will be described. However, it is obvious that such embodiments do not limit the content of the present invention.

[First Embodiment]

Into the bronze-based metal powder (75% by weight of M325 manufactured by KENNAMETAL, 25% by weight of tin), diamond powder (manufactured by GE, USA) in the range of 75 to 90 µm was added 30% by weight to the metal powder, followed by 4 hours using a tubular mixer. Mix evenly. And the grindstone fixing member shown in [FIG. 1C] is prepared by processing into predetermined shape using NC M / C. After the processed grindstone fixing member is assembled into a mold, the mixed grindstone powder is mixed into a mold. After mixing the powder, the upper part of the mold is sealed by using a punch made of carbon, and then put into a vacuum resistance furnace, and sintered and polished by a positive pressure sintering method which is heated and pressurized at a temperature of 700 ° C. and a pressure of 0.2 Ton / cm ² for 20 minutes. A superabrasive tool is produced in which the dragon particles are made of diamond only. A plurality of super abrasive tools thus prepared are inserted into a circular rubber pad and tested for grinding performance at a pressure of 0.15 kgf / cm ² at LAP M / C. When the mixing ratio of diamond and CBN is tested by repeating the above procedure with the test number of [Table 1], the result as shown in [Table 1] is obtained. The polishing amount shown in Table 1 is a relative value. [Table 1] shows that if the mixing ratio of diamond powder and CBN powder is in the range of Test Nos. 3, 4 and 5, that is, the volume ratio is 8.5: 1.5 as the upper limit and 9.5: 0.5 as the lower limit, it is continuous regardless of the number of CRT panels. Indicates a high polishing amount. On the other hand, in the case of the mixing ratio in the range of Test Nos. 1, 2, and 6, as the number of polished CRT panels increases, the amount of polishing decreases, so periodic dressing is required to continue polishing. This phenomenon occurs because the autogenous ability of the diamond particles is lowered if the mixing ratio of the diamond powder and the CBN powder is not appropriate. Therefore, when mixing the diamond and the CBN powder, the volume ratio is 8.5: 1.5 as the upper limit and 9.5: 0.5 as the lower limit.

[Table 1] Comparison of polishing performance according to the mixing ratio of diamond and CBN.

Exam number DIA amount (%) CBN amount (%) Average Grinding Amount (1-10 Grinding) Average Grinding Amount (40-50 Grinding) Average Grinding Amount (100 ~ 200 Sheet Grinding) Remarks One 65 35 104 82 55 Comparative example 2 75 25 101 86 72 Comparative example 3 85 15 98 94 92 Scope of invention 4 90 10 95 97 95 Scope of invention 5 95 5 98 95 93 Scope of invention 6 100 0 100 60 34 Comparative example

Example 2

To the abrasive grain powder obtained by mixing bronze-based metal powder (75 wt% M325 manufactured by KENNAMETAL, 25 wt% tin powder) and diamond and CBN powder having a particle size in the range of 75 to 90 μm in the ratio range shown in Example 1 above. The test powder is weighed by varying the size, toughness index and ratio of the binder to the conditions described in the test number of Table 2. The metered test powder is mixed uniformly for 4 hours using a tubular mixer. Then, after assembling the grindstone fixing member shown in [FIG. 1C] into a mold, the mixed grindstone manufacturing powder is injected into the mold. And then injecting the mixture powder using a punch with the carbon seal the top of the mold and sintered in a positive pressure sintering method to put in a vacuum resistance, at the same time allowed to warm pressing at a pressure of temperature and 0.2Ton / cm ² of 700 ℃ 20 bungan Fabricate a super abrasive tool for polishing CRT panel face. By using the same method as described above to prepare the abrasive tool of the component described in the experiment number of [Table 2] by varying the particle size, toughness value, and volume fraction of diamond and CBN. In this way, a polishing tool is prepared by inserting a super abrasive tool manufactured by varying the size, toughness, and content rate of the abrasive grain into a rubber pad, and polishing the CRT panel in LAP M / C to test the polishing property. The following Table 2 is a 15 "CRT panel 5.5 at a pressure of 0.15kgf / cm ² in a machine for grinding Garnet - 7Hz to 30 minutes - is the result of 35 seconds after the polishing test measures the roughness and the polishing amount of the cathode-ray tube panel It was judged as a result satisfactory that the powder combination which can obtain roughness Rt7 or less with respect to the grinding | polishing amount 40g required by the CRT panel polishing process actually was satisfactory.

From the results in Table 2, it is possible to obtain the required amount of polishing and roughness in the range of diamond and CBN particles in the range of 75 to 90 µm, toughness of 50 to 60, and weight percent of the abrasive grain mixed powder of 15 to 25. there was. That is, Test Nos. 16 to 19 belong to the scope of the invention, and Test Nos. 1 to 15 and 20 to 30 are outside the scope of the invention. In the case where the size of the super abrasive particles is 90 μm or more, the polishing amount satisfies the required conditions, but becomes rougher than the roughness required. In addition, the required roughness is satisfied below 75㎛, but it is not suitable for use as a product due to the small amount of polishing. In addition, depending on the content of the abrasive grain mixed powder included in the grindstone, the polishing amount and roughness tend to be different, but it can be seen that the polishing amount decreases in the range outside the upper limit of the weight percent upper limit of 15 to 25.

[Table 2] Abrasive Amount and Roughness by Abrasive Particle Size, Toughness and Content

Exam number Particle Size (μ) Toughness Content of Grinding Particles (wt%) Grinding amount (g) Roughness (Rt) Remarks One 106-90 60 to 80 25 65 13.1 Comparative Example 2 106-90 60 to 80 15 67 9.8 Comparative Example 3 106-90 60 to 80 5 75 10.1 Comparative Example 4 106-90 50 to 60 25 60 11.2 Comparative Example 5 106-90 50 to 60 15 58 10.1 Comparative Example 6 106-90 50 to 60 10 55 11.2 Comparative Example 7 106-90 50 to 60 5 64 12.1 Comparative Example 8 106-90 40-50 25 53 9.6 Comparative Example 9 106-90 40-50 15 49 10.0 Comparative Example 10 106-90 40-50 5 51 10.8 Comparative Example 11 90 to 75 60 to 80 25 42 7.6 Comparative Example 12 90 to 75 60 to 80 15 46 7.4 Comparative Example 13 90 to 75 60 to 80 5 48 8.2 Comparative Example 14 90 to 75 50 to 60 35 32 5.6 Comparative Example 15 90 to 75 50 to 60 30 36 5.4 Comparative Example 16 90 to 75 50 to 60 25 42 6.0 Scope of invention 17 90 to 75 50 to 60 22 45 6.4 Scope of invention 18 90 to 75 50 to 60 18 42 6.1 Scope of invention 19 90 to 75 50 to 60 15 44 5.9 Scope of invention 20 90 to 75 50 to 60 10 37 6.4 Comparative Example 21 90 to 75 40-50 25 31 6.1 Comparative Example 22 90 to 75 40-50 20 29 5.9 Comparative Example 23 90 to 75 40-50 15 27 6.3 Comparative Example 24 90 to 75 40-50 10 30 5.7 Comparative Example 25 90 to 75 40-50 5 33 6.7 Comparative Example 26 75-63 60 to 80 15 22 5.1 Comparative Example 27 75-63 50 to 60 5 2 4.8 Comparative Example 28 75-63 40-50 25 25 6.0 Comparative Example 29 75-63 40-50 15 18 5.4 Comparative Example 30 75-63 30-40 5 20 5.1 Comparative Example

Example 3

To the abrasive grain powder obtained by mixing the bronze-based metal powder (M325 manufactured by KENNAMETAL, 25% by weight of tin powder) and diamond and CBN powder having a particle size in the range of 30 to 38 μm in the range of the ratio as shown in Example 1 above. The size, toughness index, and ratio with the binder were varied under the conditions described in the test number of [Table 3] to be measured. The metered test powder is mixed uniformly for 4 hours using a tubular mixer. Then, after assembling the grindstone fixing member shown in [FIG. 1C] into a mold, the mixed grindstone manufacturing powder is injected into the mold. After injecting the mixed powder, the upper part of the mold is sealed by using a punch made of carbon and put into a vacuum resistance furnace, and sintered by a positive pressure sintering method which is simultaneously heated and pressurized at a temperature of 700 ° C. and a pressure of 0.2 Ton / cm ² for 20 minutes. Fabricate a super abrasive tool for polishing CRT panel face. By using the same method as described above to prepare a super abrasive tool of the component described in the experiment number of [Table 2] by varying the particle size, toughness, content of diamond and CBN. In this way, the abrasive tools in which the super abrasive materials produced by varying the particle size, toughness, and content of diamond and CBN are inserted into rubber pads are prepared, and the CRT panel is polished in an AGM machine to test the abrasiveness. Table 3 below shows the results of a 30-35 second test of a 29 "CRT panel at a frequency of 5.5-7 Hz at a pressure of 0.15 kgf / cm ² in an AGM machine. The roughness and the amount of polishing of the CRT panel after polishing were measured. It was judged that the result of satisfactory result of the combination of the powder which can obtain roughness Rt5 or less with respect to the grinding | polishing amount 80g required by the CRT panel polishing process actually.

From the results in Table 3, it is possible to obtain the required amount of polishing and roughness in the range of diamond and CBN particles in the range of 30 to 38 µm, toughness of 50 to 60, and weight percent of the abrasive grain mixed powder of 15 to 25. You can see that. That is, Test Nos. 16 to 19 belong to the scope of the invention, and Test Nos. 1 to 15 and 20 to 30 are outside the scope of the invention. And when the size of the super abrasive particles is 38㎛ or more, the polishing amount satisfies the required conditions, but rougher than roughness is required. Below 30㎛, it satisfies the required roughness, but it is not suitable for use as a product because of the small amount of polishing. In addition, depending on the content of the abrasive grain mixed powder included in the grindstone, the polishing amount and roughness tend to be different, but it can be seen that the polishing amount decreases in the range outside the upper limit of the weight percent upper limit of 15 to 25.

[Table 3] Polishing amount and roughness by size, toughness and content of abrasive grains

Exam number Particle Size (μ) Toughness Content of Grinding Particles (wt%) Grinding amount (g) Roughness (Rt) Remarks One 38 to 45 60 to 80 25 84 9.2 Comparative Example 2 38 to 45 60 to 80 15 87 9.4 Comparative Example 3 38 to 45 60 to 80 5 88 9.4 Comparative Example 4 38 to 45 50 to 60 25 78 7.5 Comparative Example 5 38 to 45 50 to 60 15 78 8.2 Comparative Example 6 38 to 45 50 to 60 10 80 9.4 Comparative Example 7 38 to 45 50 to 60 5 84 9.2 Comparative Example 8 38 to 45 40-50 25 79 7.6 Comparative Example 9 38 to 45 40-50 15 76 8.1 Comparative Example 10 38 to 45 40-50 5 79 8.5 Comparative Example 11 30 to 38 60 to 80 25 65 5.8 Comparative Example 12 30 to 38 60 to 80 15 64 5.9 Comparative Example 13 30 to 38 60 to 80 5 62 6.2 Comparative Example 14 30 to 38 50 to 60 35 62 4.5 Comparative Example 15 30 to 38 50 to 60 30 77 4.9 Comparative Example 16 30 to 38 50 to 60 25 86 4.9 Scope of invention 17 30 to 38 50 to 60 22 85 4.7 Scope of invention 18 30 to 38 50 to 60 18 83 4.8 Scope of invention 19 30 to 38 50 to 60 15 84 4.2 Scope of invention 20 30 to 38 50 to 60 10 76 4.1 Comparative Example 21 30 to 38 40-50 25 78 4.0 Comparative Example 22 30 to 38 40-50 20 75 3.8 Comparative Example 23 30 to 38 40-50 15 74 3.9 Comparative Example 24 30 to 38 40-50 10 76 3.8 Comparative Example 25 30 to 38 40-50 5 71 4.0 Comparative Example 26 20-30 60 to 80 15 42 3.2 Comparative Example 27 20-30 50 to 60 5 49 3.5 Comparative Example 28 20-30 40-50 25 38 3.5 Comparative Example 29 20-30 40-50 15 46 3.4 Comparative Example 30 20-30 30-40 5 42 3.1 Comparative Example

Example 4

FIG. 2 is a sample of vacuum-sintered super-abrasive tool by varying the sintering conditions, that is, the sintering temperature and pressure, using the mixed powder of the conditions specified in the test condition 17 of [Table 2] in Example 2. FIG. The result is. The test results are expressed based on the amount of polishing relative to 10.

2, the bronze metal powder is melted and melted without sintering at a temperature of 750 ° C or higher. In addition, at a pressure of 0.25 Ton / cm ² or more, the sintering proceeds so much that the sintering is very hard and the amount of polishing decreases. In addition, when the pressure is 0.05 Ton / cm ² or less, the bonding force between the abrasive particles and the binder is weakened due to the improper pressure, so that the grinding particles are largely eliminated during polishing, so that the polishing is hardly performed. When the sintering temperature is above 750 ℃, the binder shows some melting phenomenon and shows the same aspect as when the pressure is more than 0.25 Ton / cm ² , and below 650 ℃, the bonding strength is weakened as when the pressure is below 0.05 Ton / cm ² . It can be seen that the grinding particles are largely eliminated and hardly polished. Therefore, the most appropriate range of sintering temperature and pressure is in the range of 650-750 ℃ and pressure in the range of 0.05-0.25 Ton / cm ² as shown in [Figure 2]. Can be.

Example 5

Bronze-based metal powder (75% by weight M325 manufactured by KENNAMETAL, 25% by weight of tin powder) and diamond and CBN powder having a particle size in the range of 75 to 90 μm were mixed in the range of the ratio as shown in Example 1 Prepare the grindstone powder and mix uniformly for 4 hours using a tubular mixer. The weight percentage of abrasive grains contained in the mixed powder was 30. And the grindstone fixing member of the shape shown in FIG. 1b and the grindstone fixing member of the shape shown in FIG. 1e were prepared, respectively. After each of the grindstone fixing members is assembled into a mold, the mixed grindstone powder for mixing is injected into the mold. After injecting the mixed powder, the upper part of the mold is sealed by using a punch made of carbon and put into a vacuum resistance furnace, and sintered by a positive pressure sintering method which is simultaneously heated and pressurized at a temperature of 700 ° C. and a pressure of 0.2 Ton / cm ² for 20 minutes. A super abrasive tool for polishing the CRT panel face is manufactured for each grindstone fixing member. The same operation was carried out using a binder composed of a phenol resin containing 10 to 15% by volume diamond and 1 to 1.5% CBN and the remainder containing 10 to 30% iron oxide. Was hot-molded at a temperature of 160 to 170 ° C. at a pressure of 0.25 to 0.35 Ton / cm ² to prepare each superabrasive tool using the two types of grinding wheel fixing members.

As described above, the tool was changed for 24 hours at a pressure of 0.15 kgf / cm ² in the LAP M / C for the tool changing the coupling form between the grindstone and the grindstone fixing member. Table 4 shows the test results.

[Table 4] Grinding stones due to the coupling structure between grindstone and grindstone fixing member

Exam number Double structure Binder Number of Dropouts Remarks One Simple double structure Bronze Metal 2 Comparative Example 2 Simple double structure Iron Oxide + Resin 4 Comparative Example 3 Structure of Figure 1 Iron Oxide + Resin 0 Scope of invention 4 Structure of Figure 1 Bronze Metal 0 Scope of invention

[Table 4] shows that the grinding stones fall out in the simple double bond structure, but the grinding stones do not occur in the structure in which the groove is formed inside the upper end surface. Therefore, it can be seen that the structure of [Figure 1b] is better than the structure of [Figure 1e] when the binder is bronze metal or when iron oxide is mixed with the resin.

The present invention provides a super abrasive material abrasive for brown tube panel face face polishing without using a slurry, and does not cause scratches, and is produced when polishing is performed using a conventional CRT face face grinding tool. The problem of the environmental pollution by the slurry SLURRY and the scratch of the panel surface were solved.

In addition, the present invention is composed of a super abrasive material by using a grinding paper to efficiently construct a CRT panel surface by using a double abrasive to configure the super abrasive material to the intellectual part and the member for fixing the grindstone for fixing the point. Polished. In addition, by providing a fixing structure for firmly fixing the grindstone to the grindstone fixing member, the grinding wheel can be prevented from falling off.

The present invention having the above effects is a useful invention that solves all problems that occur when polishing by conventional CRT panel polishing tools.

Claims (15)

Grinding stone composition for CRT panel face face polishing, characterized in that the volume ratio of diamond and CuB Boron Nitride (CBN) is 8.5 and 1.5 as the upper limit and 9.5: 0.5 as the lower limit. . The method of claim 1, The diamond and CBN particles have a toughness index (Toughness Index) of 50-60 and the size of 75-90 ㎛ size of the CRT panel face grinding stone composition. The method of claim 1, The diamond and CBN particles have a toughness index of 50 to 60 and a size of 30 to 38 μm, the CRT panel face surface grinding stone composition. The method of claim 1, The diamond particles have a toughness of 50 to 60 and a size of 30 to 38 μm, and the CBN particles have a toughness of 40 to 50 and a size of 30 to 38 μm. The method according to any one of claims 1 to 4, The volume fraction of the abrasive grain mixture in which the diamond and CBN are mixed is 11-16.5%; The binder is a grindstone composition for CRT panel face surface polishing comprising a phenolic resin containing iron oxide in a volume percentage of 10 to 30%. The method according to any one of claims 1 to 4, The volume fraction of the abrasive grain mixture in which the diamond and CBN are mixed is 11-16.5%; The binder is composed of tin and copper having a particle size of 38-45 μm, and the volume percentage of copper is 20-30%, wherein the grindstone composition for polishing a CRT panel face surface. A substantially cylindrical member protrudes from a lower portion of the abrasive grindstone, and an abrasive grindstone having an annular protrusion formed at a lower edge of the cylindrical member; The abrasive grindstone is fixed to the upper section, the lower part of the CRT panel face is characterized by consisting of a cylindrical grindstone fixing member having an annular groove so as to be firmly fixed to the polishing tool for polishing the CRT panel face surface. Super abrasive tool for surface grinding. A substantially cylindrical member protrudes from the lower portion of the abrasive grindstone, and has a polishing grindstone having an insertion protrusion for engaging with the abrasive stone fixed member; The abrasive grindstone is fixed to the upper section, and the lower part is made of a cylindrical grindstone fixing member having an annular groove so as to be firmly fixed to the polishing tool for polishing the CRT panel face surface. Super abrasive tool for face grinding. A substantially cylindrical member protruding from the lower portion of the abrasive grindstone, the abrasive grindstone having a screw-shaped uneven portion formed on the entire outer circumferential surface of the cylindrical member so as to be combined with the grindstone fixing member; The abrasive grindstone is fixed to the upper section, and the lower part is made of a cylindrical grindstone fixing member having an annular groove so as to be firmly fixed to the polishing tool for polishing the CRT panel face surface. Super abrasive tool for face grinding. The method of any one of claims 7 to 9; The abrasive grindstone is a CRT panel face, characterized in that the volume ratio of diamond and cubic boron nitride (CBN) is composed of abrasive particles and binders mixed at an upper limit of 8.5: 1.5 and a lower limit of 9.5: 0.5. Surface polishing tools. The method of claim 10; The diamond and CBN particles have a toughness index (Toughness Index) of 50-60 and the size of 75-90 ㎛ size of the CRT panel face grinding abrasive tool. The method of claim 10, The diamond and CBN particles have a toughness index (Toughness index) of 50-60 and size of 30-38 ㎛ super polishing material for a CRT panel face. The method of claim 10, The diamond particles have a toughness of 50-60 and a size of 30-38 μm, and the CBN particles have a toughness of 40-50 and a size of 30-38 μm. Manufacturing method of super abrasive tool for polishing CRT panel face (A) Volume fraction of abrasive grain mixture mixed with diamond and Cubic Boron Nitride so that the volume ratio is 8.5: 1.5 as the upper limit and 9.5: 0.5 as the lower limit, 11-16.5% and volume fraction 10- First step to prepare a mixed powder for grinding stone by mixing the binder composed of phenol resin containing 30% iron oxide (B) Second step of assembling the grindstone fixing member manufactured in the mold to fix the grindstone (C) a third step of putting the mixed powder into the steel mold and sealing the upper part of the mold by using a carbon punch; (D) a fourth step of hot forming the mixed powder at a pressure of 0.25-0.35 ton / cm ² and a temperature of 160-170 ° C in the mold inserted into the vacuum resistance furnace; Manufacturing method of super abrasive tool for polishing CRT panel face (A) Volume fractions of abrasive grain mixtures mixed with diamond and Cubic Boron Nitride so that the volume ratio is 8.5: 1.5 as the upper limit and 9.5: 0.5 as the lower limit, 11-16.5% and 38-45 ㎛ The first process consists of tin and copper having a particle size of and the volume percentage of copper is 20-30% and the binder is made of tin to prepare a mixed powder for the production of grindstone (B) Second step of assembling the ground stone fixing member manufactured to fix the ground stone into the carbon mold (C) a third step of putting the mixed powder into the carbon mold and sealing the upper part of the mold by using a carbon punch; (D) a fourth step of hot forming the mixed powder into the vacuum resistance furnace at a pressure of 0.1-0.25 ton / cm ² and a temperature of 650-750 ° C.