KR101898120B1 - Method of manufacturing of grinding wheel for grinding edge of glass substrate - Google Patents

Abstract

The edge including the thin film glass hole is processed so that the edge of the abrasive grains is prevented from falling off, the lifetime is long, the shape of the cutting tip is not distorted, and the separation and deformation of the cutting tip and the shank do not occur A cutting wheel for machining an edge and a manufacturing method thereof are presented. The wheel and method includes a core body coupled to a shank and a core having a smaller diameter than the core body and extending from the core body, the one side of the core being in contact with the contact portion of the core body and surrounding the fixed axis, And a cutting tip having at least one cutting groove along the cutting edge, wherein the cutting tip is manufactured through sintering.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a grinding wheel for grinding an edge of a glass substrate,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a wheel for edge processing of a substrate, and more particularly, to a method of manufacturing a cutting wheel for finishing an edge of an edge by grinding or grinding a glass substrate edge having a small thickness.

A thin film glass having a thickness of about 100 μm to 700 μm is used for a display device applied to a mobile device, a tablet PC, and the like. Specifically, a panel or a front glass such as an LCD, an LED, and an OLED applied to the display is thinned due to a change in design, and a tempered glass is applied to improve rigidity. In order to mount hardware such as a camera lens, an earphone, and various sensors in the bezel area, holes of approximately 2 to 10 mm in diameter exist. Inside the hole, edge processing is performed to prevent damage such as chipping and propagation of minute cracks. In order to perform edge machining, a small-sized edge machining wheel is required which is inserted into the hole and grinds or grinds the edge of the hole. However, since the work piece is a thin glass, edge machining of the hole is difficult to avoid damage such as chipping and crack propagation due to the processing load of the wheel.

Korean Patent No. 10-1399905, Korean Patent No. 10-1605484, Japanese Patent Laid-Open No. 2001-025974, and US Patent No. 8,721,392 disclose a method of processing an edge of a glass substrate. However, It is not suitable for machining edges. That is, the edge processing wheels shown in the above patents can process the edge of the glass substrate, not the holes, and are difficult to use especially for thin film glasses having a thickness of 100 μm to 700 μm. In other words, there is no cutting wheel for machining both the edge of the thin glass and the edge of the hole.

On the other hand, a wheel for machining an edge including a thin-film glass hole has a cutting tip. The cutting tip must have adequate surface roughness so that no traces of machining are left, and the abrasion of the abrasive grains should not occur. In addition, the wear of the cutting tip is small and the service life thereof must be long, so that there is no distortion of the shape of the cutting tip due to the working load applied to the cutting tip. Further, a bonding force is sufficient on the joining portion of the cutting tip and the shank, so that breakage of the joining portion must be prevented. Of course, it is obvious that there is no damage to the thin glass such as chipping and propagation of fine cracks in processing an edge including a thin-film glass hole.

Conventional cutting wheels for edge machining are mainly limited to edge machining, but an electrodeposition method in which a nickel layer is formed by electroplating or electroless plating on abrasive grains such as diamond is used. In the electrodeposition method, a diamond layer is formed as one layer or a multilayer of two or three layers. However, in the electrodeposition method, the wettability of the diamond and nickel layers is weak, and the diamond is dropped early, and the shape is deformed by the abrasion of the cutting tip. As the thickness of the cutting tip increases, the shape distortion of the cutting tip occurs due to the overcurrent density of the edge portion. Accordingly, a cutting wheel manufactured by an electrodeposition method is not suitable for machining an edge including a thin-film glass hole. Further, the conventional cutting wheel is joined to the shank by soldering. In this case, the soldering portion is damaged due to overload generated in the process of edge machining, so that the shank and the cutting tip are separated or the soldering portion is deformed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for machining an edge including a thin glass hole to prevent the removal of abrasive grains and the removal of abrasive grains, And a method of manufacturing a cutting wheel for machining an edge of a glass substrate in which deformation does not occur.

A method of manufacturing a cutting wheel for machining an edge of a glass substrate for solving the problems of the present invention includes first mounting a core having a fixed shaft extending from the core body to the core mounting base. Thereafter, the core mounting table on which the core is mounted is placed in the hollow of the mold. And the mixed powder containing abrasive grains and a metal binder is filled on the core mounting table on which the core is mounted. An upper punch is placed on the mixed powder. Heat and pressure are applied to the mixed powder by using the mold and the upper punch to sinter the mixed powder. The sintered mixed powder and the core mount are separated into a single cutting tip body and a core. A cutting groove is formed around the cutting tip.

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In the method of the present invention, the individual cutting tip bodies and cores may be separated by wire discharge machining. The mold, the upper punch, and the core mount are preferably made of an electrically conductive material.

According to the method of manufacturing a cutting wheel for machining an edge of a glass substrate of the present invention, an edge including a thin-film glass hole can be processed by applying a core for fixing a cutting tip produced by sintering, , The abrasion of the abrasive grains is prevented, the life is long, and the shape of the cutting tip is not distorted. In addition, since the cutting tip is supported by the core, it is possible to prevent the breakage of the cutting tip or the shape change during the dressing process by making the shape of the cutting wheel. Further, since the cutting tip is inserted into the shank through the core, separation and deformation of the joint portion between the shank and the core do not occur.

1 is an exploded perspective view showing a cutting wheel for machining an edge of a glass substrate according to the present invention.
FIG. 2 is a cross-sectional view illustrating an example in which a cutting wheel according to the present invention is used.
3 to 5 are perspective views for explaining a method of manufacturing a cutting wheel for machining an edge of a glass substrate according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

In the embodiment of the present invention, by using a core for fixing a cutting tip produced by sintering, an edge including a thin-film glass hole can be machined, no machining marks are left, the abrasion of the abrasive is prevented, A method of manufacturing a cutting wheel without breakage or shape distortion of the cutting tip is presented. To this end, the structure of the cutting wheel according to the embodiment of the present invention will be described in detail and the process of manufacturing the cutting wheel will be described in detail. A method of processing a thin glass edge using the cutting wheel of the present invention will be described in detail. On the other hand, the edge refers to the side surface of the thin film glass edge or the side surface of the hole, and here, the edge of the thin glass hole will be mainly described.

1 is an exploded perspective view showing a cutting wheel for machining an edge of a glass substrate according to an embodiment of the present invention.

Referring to FIG. 1, the cutting wheel of the present invention comprises a shank 10, a core 20, and a cutting tip 30. The shank 10 has a shank body 11 and a core insertion groove 12 into which the core 20 is inserted. As the shank body 11, a cylindrical shape is generally used, but a square shape or the like can be applied in some cases. The shank body 11 may be made of any one selected from the group consisting of ordinary steel, stainless steel, aluminum, magnesium, titanium, aluminum alloy, magnesium alloy, and titanium alloy. Although not shown, the shank body 11 is connected to driving means for imparting rotational force and a control unit for precisely controlling the rotational force and the movement.

The core 20 has a fixed shaft 22 extending from the core body 21 for fixing the cutting tip 30. The fixed shaft 22 serves as a skeleton for firmly fixing and supporting the cutting tip 30, so that the cutting tip 30 can maintain a long life. The fixed shaft 22 is preferably a rectangular polygonal or cylindrical shape and may include concavities and convexities on the surface thereof in order to enhance the bonding force with the cutting tip 30. In the drawing, a cylindrical fixing shaft 22 having no surface irregularities is taken as an example. The average diameter of the fixed shaft 22 is required to be at least 30% of the average diameter of the cutting tip 30 since the rigidity required to support the cutting tip 30 in the environment in which the cutting wheel of the present invention is used is required. Considering the rigidity of the core 20 capable of supporting the cutting tip 30, a high strength metal such as high strength stainless steel is suitable.

The contact portion 23 is a portion to which one side of the cutting tip 30 is contacted and is formed on one surface of the core body 21. [ The shape of the contact portion 23 is variously set. For example, the contact portion 23 may be in the form of a dome, or even in the form of a depression. The shape of the contact portion 23 is considered such that sufficient bonding force between the cutting tip 30 and the contact portion 23 is secured in the process of manufacturing the cutting wheel of the present invention by the sintering method. In some cases, irregularities may be provided on all or a part of the contact portion 23 to increase the anchor effect with respect to the cutting tip 30.

 The cutting tip 30 surrounds the fixed shaft 22 of the body 31 and is joined to the contact portion 23 to be integrated with the core 20. It is preferable that the core body 21 and the cutting tip body 31 are cylindrical and their diameters are equal to each other. The cutting tip 30 has a plurality of cut grooves 32 along its circumference. The cutting groove 32 will be described later in detail with reference to FIG. 2 as an example, but it is an example for machining an edge of a thin glass hole. The cutting tip 30 comprises an abrasive for cutting, the abrasives contacting the thin glass edge to effect substantial cutting, and a high hardness material is used for this purpose. For example, natural or artificial diamonds, cubic boron nitride (cBN), silicon carbide (SiC), titanium carbide (TiC), and various other carbide particles can be widely used as the abrasive grains. In addition, the cutting tip 30 is a sintered body which is sintered using various metal binders, a solvent, and a binder together with the abrasive grains.

2 is a cross-sectional view illustrating an example of using a cutting wheel according to an embodiment of the present invention. At this time, in the processing of the edge of the thin film glass, a thin glass hole was exemplified.

2, the presented cutting wheel is for machining the edge of the hole 102 formed in the thin film glass 100. As shown in Fig. A thin film glass having a thickness of about 100 μm to 700 μm is used for a display device applied to a mobile device, a tablet PC, and the like. Specifically, panels such as LCDs, LEDs, and OLEDs applied to the display, or front glass, are thinned and tempered glass is applied. In order to mount hardware such as a camera lens, an earphone, and various sensors in the bezel area, There is a hole 102 of about 2 to 10 mm. At the edge of the hole 102, machining proceeds to prevent damage such as chipping and propagation of micro cracks by the cutting wheel of the present invention.

The cutting wheel of the present invention is a small-sized edge-processing wheel that is inserted into the hole 102 to cut the edge of the hole 102 for edge machining of the hole 102. Specifically, when the cutting tip 30 is inserted into the hole 102, the cut groove 32 is aligned with the edge of the hole 102, and then the cutting tip 30 is rotated, the edge of the hole 102 is cut And is processed in the shape of the groove 32. The cutting groove 32 is concavely rounded so that the edge of the hole 102 is rounded. If the edge of the hole 102 is cut so as to be rounded, damage such as chipping and micro crack propagation at the edge can be prevented.

3 to 5 are perspective views for explaining a method of manufacturing a cutting wheel for machining an edge of a glass substrate according to an embodiment of the present invention. In the case of FIG. 3, a portion is cut out for convenience of explanation. Here, the cutting wheel will be referred to FIG. 1, and a detailed description of the overlapping portions will be omitted.

Referring to FIG. 3, in the method of manufacturing a cutting wheel according to the present invention, a plurality of cores 20 are mounted on a hollow 41 of a mold 40 mounted on a groove formed in a core mount 43. The mold 40 and the core mount 43 are preferably made of an electrically conductive material such as carbon for sintering heating. Thereafter, a powder 33 mixed with various metal binders, a solvent and a binder is filled on the core mount 43 on which the core 20 is mounted together with abrasive grains. Subsequently, an upper punch 42 made of carbon, which is a conductive material, is disposed on the filled mixed powder 33. The core mount 43 on which the core 20 is mounted, the mixed powder 33 and the upper punch 42 are sequentially positioned in the hollow 41 of the mold 40. [ Although the mold hollow 41 is represented by a cylindrical shape in the drawing, the mold hollow 41 may be a different shape, for example, a rectangular parallelepiped space.

On the other hand, in order to smoothly separate the mixed powder 33 from the upper punch 42 and the mold 40, it is preferable to form a release layer 44 made of a release material such as graphite on the surface of the mixed powder 33. Next, while applying heat to the mold 40, the core mounting table 43 and the upper punch 42, pressure is applied to the upper punch 42 to sinter the mixed powder 33. The heat and pressure are appropriately set in consideration of the components of the mixed powder 33 and the like. By the sintering, the core mount 43 on which the core 20 is mounted is sealed with the sintered mixed powder 33. After the sintering, the core mounting base 43 sealed with the sintered mixed powder 33 and the mixed powder 33 is separated from the mold 40.

According to Fig. 4, the sintered mixed powder 33 and the core mount 43 are separated into a single cutting tip body 31 and a core 20. That is, the core 20 is separated. The cutting tip body 31 and the core 20 are preferably separated from each other by a wire electric discharge machining method using CNC. The wire is a kind of discharge machining. Discharge machining, also called spark machining, is a method of machining into a spark that occurs when an electric anode and cathode strike each other. The heat generated by the spark melts or vaporizes the material to be machined to the desired shape. The spark discharge is controlled to occur rapidly in a very narrow range and precision machining is possible because the cutting tip body 31 and the machined portion of the core 20 are melted or vaporized and removed. Particularly, a method of cutting along the contour by utilizing a wire is called a wire contouring method.

For electrical discharge machining, the cutting tip body 31 and the core 20, which serve as positive electrodes to cause sparks, are electrically conductive. Wire contouring means that the electrode becomes a wire (eg copper wire and brass wire) and is controlled by the CNC control method. As described above, the individual cutting tip body 31 and the core 20 according to the embodiment of the present invention are cut in a wire contour processing manner.

5, cutting grooves 32 are formed along the circumference of the individual cutting tip body 31 to complete the cutting wheel of the present invention. The cutting grooves 32 may be formed by various methods, for example, by removing the metal bonding material of the cutting tip body 31 with abrasive grains such as silicon carbide (SiC) and alumina (Al ₂ O ₃ ) To the dressing process. The cutting grooves 32 can be formed at any one of the positions before or after the core insertion grooves 12 of the shank 10 are inserted. An adhesive or the like can be used to join the shank 10 to the core 20. [

If there is no core 20, it is difficult to shape the cutting wheel after sintering or to avoid breakage or shape distortion of the cutting tip 30 during the dressing process. However, if the core 20 is present, Can support the cutting tip 30, thereby making it possible to prevent the cutting tip 30 from being damaged or distorted during the dressing process. Further, since the cutting tip 30 and the shank 10 are conventionally joined by soldering, separation and deformation of the portion where the shank 10 and the cutting tip 30 are joined due to overloading occur in the course of processing the edge . On the other hand, since the core 20 of the present invention is inserted into the core insertion groove 12 of the shank 10, separation and deformation of the joint portion between the shank 10 and the core 20 do not occur.

The cutting wheel according to the embodiment of the present invention can process thin glass holes and rims. Since the cutting tip is manufactured by a sintering method, it has an appropriate surface roughness such that no trace of machining remains, and the abrasion of the abrasive does not occur. Further, since the wear of the cutting tip is small, the service life is long, and there is no distortion of the shape of the cutting tip due to the working load applied to the cutting tip. Further, the bonding force is sufficient on the joint of the cutting tip and the shank, and breakage of the joint is prevented. Of course, the cutting wheel of the present invention can perform machining without damaging the thin glass such as chipping and propagation of micro cracks in machining the edge of the thin glass frame and the hole. Particularly, since the core 20 supports the cutting tip 30, it has an advantage of minimizing the shaking of the cutting tip 30 during machining, which is advantageous for preventing propagation of chipping and micro cracks.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications may be made without departing from the spirit and scope of the invention. It is possible.

10; Shank 11; Shank body
12; Core insertion grooves 20; core
21; A core body 22; Fixed shaft
23; A contact portion 30; Cutting tip
31; A cutting tip body 32; Cutting groove
40; Mold 41; Mold hollow
42; Upper punch 43; Core mount
44; Heterogeneous layer

Claims (11)

delete delete delete delete delete delete delete delete A core having a diameter smaller than the diameter of the shank and having a diameter smaller than the diameter of the shank and extending from the core body; and one side of the core being in contact with the contact portion of the core body, And a cutting insert having at least one cutting groove along a circumference of the cylindrical shape, the shank including a core insertion groove into which the core body is inserted, the cutting tip being inserted into the thin glass hole, A method of manufacturing a cutting wheel for machining an edge of a hole,
Mounting a plurality of cores having fixed shafts extending from the core body to the core mount;
Placing the core mount on which the core is mounted in the hollow of the mold;
Filling a mixed powder including abrasive grains and a metal binder on the core mounting table on which the core is mounted;
Disposing an upper punch on the mixed powder; And
Sintering the mixed powder by applying heat and pressure to the mixed powder using the mold and the upper punch;
Separating the sintered mixed powder and the core mount into a single cutting tip body and a core; And
And forming a cutting groove around the cutting tip,
Wherein the thickness of the thin glass is 100 to 700 μm, the diameter of the hole is 2 to 10 mm, and the diameter of the fixed shaft is larger than 3/10 of the diameter of the cutting tip. A method of manufacturing a wheel. 10. The method of claim 9, wherein the individual cutting tip bodies and cores are separated by wire electrical discharge machining. 10. The method of claim 9, wherein the mold, the upper punch, and the core mount are made of an electrically conductive material.

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