In detail, a cutting wheel, which is mounted in a cutting apparatus having a holder m ember for a cone type cutter, comprises inclined surfaces at both sides of a scribe line form ed on the center of the cutting wheel, wherein a conical surface is integrally formed on the outer side of each inclined surface, and general cutting grooves are formed on the scribe lin e at equi-intervals by means of a cutting groove making apparatus of an electric discharge machining type or a laser type.

Background Art Fig. 6 is an exemplary view of a portable nonmetal cutting apparatus 50.

The nonmetal cutting apparatus 50 is used to form a straight or curved scribe line on a surface of a workpiece, such as glass and a TFT-LCD, by rotating a cutting wheel 52 at a predetermined speed, wherein the cutting wheel 52 is mounted in the lower end of a head 5 1 with an engaging pin 53 and is rotated by a driving means installed in a main body (grip portion) of the cutting apparatus.

As described above, the nonmetal cutting apparatus 50 has been used with the conve ntional disc-type cutting wheel 52 mounted therein.

The conventional disc type cutting wheel 52, which is disk-shaped, is formed with a scribe line on the center line of the outer perimeter thereof, wherein edge surfaces are form ed with an inclination downward out of both sides of the scribe line, wherein cutting groov es with a predetermined size, though not concretely shown, are formed on the scribe line at equi-intervals.

Such a conventional disc type cutting wheel 52 is mounted by means of a DC pin (P CD shaft type), which is engaged with an inner diameter of a tool (the cutting wheel) in or der to rotate and press the tool (the cutting wheel). Such an engaging method using the to ol (the cutting wheel) or the pin can lengthen a life of the tool (the cutting wheel) by far as compared with a method using a cemented carbide tool (the cutting wheel) and shows prop erties sufficient for requisite to perform scribing.

However, the conventional processing method does not solve a problem of wear of c ontact portions caused from axial friction, which is a major cause to shorten a life of a scri be line during the processing, and has a limitation of decreasing the outer diameter of the s cribe line of the tool (the cutting wheel) taking applied pressure and a size of the inner dia meter of the tool (the cutting wheel) into consideration. Furthermore, according to the pri or art, in order for contaminant not to be generated, a lubricationless method has been used by excluding use of liquid or solid lubrication, causing a life of the tool (the cutting wheel ) to be considerably shortened due to the axial friction, and vibration from axial wear to be generated.

In particular, the conventional inner diameter engaging method has the limitation tha t the outer diameter of the tool (the cutting wheel) of over 1. 5mm should be maintained du e to restriction of a shaft portion.

Furthermore, the conventional disk type cutting wheel 52 has been formed with the c utting grooves by means of a grinding wheel. Referring to Fig. 2, rapid wear of the grindi ng wheel causes an interval D 1 and a depth H of the cutting groove, an interval between th e base portions of the adjacent cutting grooves, i. e., a cutting projection interval D2, and a pitch P consisting of the cutting groove interval D1 and the cutting projection interval D2 n ot to be constant, so that a quality of the disk type cutting wheel 52 is considerably deterior ated.

If a workpiece of nonmetal, such as glass and a TFT-LCD, is scribed by using the di sk type cutting wheel 52, wherein the pitch P and the depth H are not constant, a scribe line is generated on the workpiece and simultaneously horizontal cracks are also generated irr egularly around the scribe line. In addition, regular vertical cracks cannot be generated u p to the bottom surface of the workpiece.

Accordingly, when the workpiece is broken, due to the scribe line and the irregular c racks, the workpiece cannot be broken continuously as well as smoothly, and an irregular b roken surface is generated, causing a quality of the workpiece to be considerably deteriorat ed.

Disclosure of Invention The present invention intends to provide a cone type PCD scriber cutter so as to solv e the problems described above and an apparatus and a method for making cutting grooves thereof.

It is an object of the present invention to provide a cone type PCD scriber cutter, wh erein the interval and the depth of the cutting grooves formed on a scribe line and the cutti ng projection interval are enabled to be constant, smooth inner surfaces of the cutting groo ves can be maintained, and a quality and productivity of the cone type scriber cutter can be improved, and to provide an apparatus and a method for making cutting grooves thereof It is another object of the present invention to provide a cone type PCD scriber cutter , wherein a scribe line can be formed straightly when a workpiece is scribed with a constan t pitch P consisting of the cutting groove interval and the cutting projection interval consta nt, uniform cracks are generated up to the bottom surface of the workpiece, and the workpi ece can be broken continuously and smoothly, and to provide an apparatus and a method fo r making cutting grooves thereof.

The cone type PCD scribe cutter of the present invention for achieving the above obj ects, comprises: edge surfaces 3 formed at both sides of a scribe line 2, which is formed on the center of the cutter; cutting grooves 5 formed on said scribe line 2; and conical surfac es 4, each of which is integrally formed on the outer side of each edge surface 3; wherein t he general cutting grooves 5 on said scribe line 2 are formed at equi-intervals by an electric discharge machining or a laser.

According to another aspect of the present invention for achieving the objects, there i s provided an electric discharge machining apparatus for making cutting grooves of a cone type scribe cutter, which is operated by a computer numeral control (CNC), comprising: a support 11 mounted on the electric discharge machining apparatus; an electrode brass bar 1

2 mounted on said support 11 ; an electrode wheel 13 fixed to the distal end of said electrod e brass bar 12 using adhering plates 14 with a general bolt 15; and cemented carbide auxili ary shank 16, to which a cone type scriber cutter 1 is mounted below said electrode wheel 13 mounted to said electrode brass bar 12, and which is rotated intermittently by the predet ermined angle by a general rotating means.

According to another aspect of the present invention for achieving the objects, there i s provided an apparatus for making cutting grooves of the cone type scribe cutter, which cu ts a workpiece using a radiated laser beam, comprising: a laser rod 21, at the outside of whi ch a xenon tube 22 for excitation is provided and which is vertically installed so that the la ser beam is generated downward; a lens 23, which is provided below the laser rod 21 so th at the laser beam generated from the laser rod 21 can be concentrated; and upper and lower side setting jigs 24,25, which are freely rotated and installed with a spacing below the len s 23, wherein the upper side setting jig 24 can be actuated upward and downward by a gen eral actuating means, and the lower side setting jig 25 is mounted on a rotating plate 26 an d then can be rotated intermittently by the predetermined angle by a general rotating means According to another aspect of the present invention for achieving the objects, there i s provided a method for making cutting grooves of the cone type scribe cutter by means of an electric discharge machining apparatus, which is operated by a computer numeral contr ol (CNC) and cuts a workpiece, comprising steps of : mounting an electrode brass bar 12 on a rotating means of the electric discharge machining apparatus and mounting an electrode wheel 13 on the distal end of said electrode brass bar 12; fixing a cone type scriber cutter 1, below said electrode wheel 13, to a cemented carbide auxiliary shank 16, which is rotate d intermittently by the predetermined angle by a general rotating means; and forming gener al cutting grooves 5 having a constant interval Dl and a constant depth H sequentially one by one with a spacing of a cutting projection interval D2, by rotating the cone type scriber cutter 1 fixed to the cemented carbide auxiliary shank 16 intermittently by the predetermin ed angle and by contacting the electrode wheel 13 of the electrode brass bar 12, which rota tes and to which electric power is supplied, with a scribe line 2 of the cone type scriber cutt er 1.

According to another aspect of the present invention for achieving the objects, there is provided another method for making cutting grooves of a cone type scribe cutter compr ising steps of : setting a cone type scriber cutter 1 in upper and lower side setting jigs 24,25 , which are rotated intermittently by the predetermined angle by a general rotating means; concentrating a laser beam through a lens 23 wherein the laser beam is non-continuously ra diated in pulse phase from a laser rod 21, at the outside of which a xenon tube 22 for excita tion is installed; forming general cutting grooves 5 having a constant interval D1 and a con stant depth H sequentially one by one with a spacing of a cutting projection interval D2, by radiating the laser beam concentrated through said lens 23 to a scribe line 2 of the cone ty pe scriber cutter 1, which is rotated intermittently by the predetermined angle by a rotating means.

More concretely, in the method for making cutting grooves of a cone type scribe cutt er, a focus distance of the laser beam generated from the laser rod 21 and concentrated to t he workpiece through said lens 23 is 0. 0001-0. 003mm.

Brief Description of Drawings Fig. 1 is a front view and a side view of a cone type PCD scriber cutter according to the present invention.

Fig. 2 is a partially enlarged view showing a state of cutting grooves formed on a scr ibe line of the cone type PCD scriber cutter according to the present invention.

Figs. 3a and 3b are exemplary views of an electric discharge machining type cutting groove making apparatus for forming the cutting grooves on the cone type PCD scriber cut ter according to the present invention and the forming state of the cutting grooves.

Fig. 4 is an exemplary view of a laser type cutting groove making apparatus for form ing the cutting grooves on the cone type PCD scriber cutter according to the present invent ion and the forming state of the cutting grooves.

Fig. 5 is an exemplary view showing the cone type PCD scriber cutter according to t he present invention, which is installed in a holder member of a nonmetal cutting apparatus Fig. 6 is an exemplary view of a conventional cutting apparatus.

Best Mode for Carrying Out the Invention The above and other objects and features of the present invention are more clearly u nderstood from the descriptions below with reference to the accompanying drawings.

Figs. 1 a to 5 are exemplary views showing a cone type PCD scriber cutter according to the present invention and examples embodying a scribing process of the cone type PCD scribe cutter: Fig. 1 is a front view and a side view of the cone type PCD scriber cutter acc ording to the present invention; Fig. 2 is a partially enlarged view showing a state of cuttin g grooves formed on a scribe line; Figs. 3a, 3b and 4 are exemplary views of a cutting groo ve making apparatus of an electric discharge machining type and a laser type for forming t he cutting grooves; and Fig. 5 is an exemplary view showing the cone type PCD scriber cut ter according to the present invention, which is installed in a holder member of a nonmetal cutting apparatus.

As shown in Figs. la and lb, a cone type scriber cutter 1 according to the present inv ention is formed with edge surfaces 3 on both sides of a scribe line 2, which is formed on t he center of the scriber cutter 1, wherein a conical surface 4 is integrally formed on the out er side of each edge surface 3 so that the cutting wheel is formed in diamond conical shape , and cutting grooves 5 are formed on the line 2 at equi-intervals, as shown in Fig. 2.

The cutting grooves 5 are formed on the scribe line 2 of the cone type scriber cutter 1 at equal intervals by means of an electric discharge machining type cutting groove makin g apparatus 10 as shown in Figs. 3a and 3b or a laser type cutting groove making apparatus 20 as shown in Fig. 4.

In the electric discharge machining type cutting groove making apparatus 10 shown i n Figs. 3a and 3b, a support 11 is mounted on an electric discharge forming apparatus, whi ch is actuated (rotatably, upward and downward) by a computer numeral control (CNC) no t concretely shown. An electrode brass bar 12 formed of copper (Cu) is mounted on the s upport 11. An electrode wheel 13, to both sides of which adhering plates 14 for fixation a dhere, is fixed to the distal end of the electrode brass bar 12 by means of a conventional m ounting bolt 15. A cone type scriber cutter 1 is mounted on a cemented carbide auxiliary shank 16 and is provided below the electrode wheel 13 mounted on the distal end of the ele

ctrode brass bar 12. The cemented carbide auxiliary shank 16 and therefore the cone type scriber cutter 1 are rotated intermittently by the predetermined angle by a rotating means of a cross table not concretely shown.

Fig. 4 is an exemplary view of a laser type cutting groove making apparatus 20 as an other embodiment of a cutting groove making apparatus for forming cutting grooves 5 on t he cone type PCD scriber cutter 1 according to the present invention.

In the laser type cutting groove making apparatus 20, a laser rod 21 is vertically insta lled in a supporting axis (not concretely shown) of a forming apparatus frame and a xenon tube 22 for excitation is installed outside the laser rod 21, so that a laser beam is generated downward. A lens (sphero-cylindrical lens) 23 is installed below the laser rod 21, so that the laser beam generated from the laser rod 21 can be concentrated. Upper and lower side setting jigs 24,25, which are freely rotated, are installed with a spacing below the lens 23.

While the upper side setting jig 24 can be actuated upward and downward by an upward and downward actuating means not concretely shown, the lower side setting jig 25 is moun ted on a rotating plate 26 and then can be rotated intermittently by the predetermined angle by a general rotating means not concretely shown.

Using the electric discharge machining type cutting groove making apparatus 10 or t he laser type cutting groove making apparatus 20 as constituted above, a method for formi ng the cutting grooves 5 on the scribe line 2 will be described concretely.

First, using the electric discharge machining type cutting groove making apparatus 1 0, a method for forming the cutting grooves 5 on the scribe line 2 of the cone type PCD scr iber cutter 1 will be described.

The adhering plates 14 for fixation, which are provided with the electrode wheel 13, are mounted on the electrode brass bar 12. After a circular cylindrical material is welded to the cemented carbide auxiliary shank 16 of the rotating means mounted on the cross tabl e (not concretely shown) by a vacuum welding method, a general cone type PCD scriber c utter 1 without surface features are previously manufactured. Under the mounted state as above, by actuating a switch (not concretely shown), electric power is supplied through the electrode brass bar 12 to the electrode wheel 13. At the same time, the electrode wheel 13 together with the electrode brass bar 12 rotate and are moved downward, so that the ele

ctrode wheel 13 is in contact with the scribe line 2 of the cone type PCD scriber cutter 1.

When the electrode wheel 13 is in contact with the scribe line 2 of the cone type PC D scriber cutter 1, electric discharge is generated between the scribe line 2 and the electrod e wheel 13, to which electric power is supplied, so that the electric discharge causes the cut ting groove 5 having the interval D1 and the depth H to be formed on the scribe line 2, as s hown in Fig. 2.

After the cutting groove 5 is formed on the scribe line 2 as performed above, the elec trode wheel 13, which rotates, is moved upward together with the electrode brass bar 12.

With the electrode wheel 13 rotating and positioned upward, the cone type PCD scriber cut ter 1 is rotated together with the cemented carbide auxiliary shank 16 by the predetermined pitch P, which is divided by N, by the rotating means of a cross table in order to obtain de sired certain features. If the rotation of the cone type scriber cutter 1 is completed, by mo ving the electrode wheel 13 together with the electrode brass bar 12 downward, another cut ting groove 5 having the interval D1 and the depth H is formed on the scribe line 2 so as to be adjacent to the previously formed cutting groove 5.

By performing the above process repeatedly, the electric discharge machining type c utting groove making apparatus 10 according to the present invention may form the cutting grooves 5 having the interval Dl and the depth H on the scribe line 2 at constant intervals , so that cutting projections 6 with the constant cutting projection interval D2 are formed b etween the adjacent cutting grooves 5.

In the case that a computer numeral control (CNC) is employed in order to obtain the surface features of the cutting grooves 5 and the cutting projections 6 as above, the consta nt width D1 and the constant depth H of the cutting grooves 5 can be precisely formed in a short time by the precise division of the computer numeral control (CNC). In order to pre cisely form the width Dl and depth H of the cutting grooves 5 by electric discharge machi ning, it is preferable that concentricity of the electrode wheel 13 is constant and that variati on of wear of the electrode wheel 13 caused by electric discharge does not occur. The fix ing plates 14 fixed to both sides of the electrode wheel 13 prevent the thin electrode wheel from being bent, wherein the bend is caused by physical and electrical influence thereof.

In the meantime, using the laser type cutting groove making apparatus 20 shown in F

ig. 4, a method for forming the cutting grooves 5 on the scribe line 2 is performed as follo ws.

With the upper side setting jig 24 positioned upward, an apex of one of the conical s urfaces 4 of the cone type scriber cutter 1 is mounted on the lower side setting jig 25. Th en, the apex of the other conical surface 4 is constrained by moving the upper side setting j ig 24 downward so that the cone type scriber cutter 1 is vertically maintained.

If the laser type cutting groove making apparatus 20 is operated by actuating a switc h (not concretely shown) under the state that the cone type scriber cutter 1 is vertically mai ntained by means of the upper and lower side setting jigs 24,25, a laser beam in pulse phas e is non-continuously radiated from the laser rod 21, at the outside of which the xenon tube 22 for excitation is installed. The laser beam radiated from the laser rod 21 is concentrat ed through the lens (sphero-cylindrical lens) 23 onto the scribe line 2 of the cone type scrib er cutter 1 with the focus distance of 0. 0001-0. 003mm. The cutting groove 5 having the interval D1 and the depth His formed on the scribe line 2 of the cone type scriber cutter 1 by the concentrated laser beam, as shown in Fig. 2.

After the cutting groove 5 is formed on the scribe line 2 as performed above, with th e lens 23 and laser rod 21 positioned upward, the rotating plate 26 and therefore the setting jigs 24,25 and the cone type scriber cutter 1 mounted on the setting jigs 24,25 are rotated by the predetermined pitch P by actuating the rotating means, on which the cone type scri ber cutter 1 is mounted. After the rotation of the cone type scriber cutter 1, by moving th e lens 23 and laser rod 21 downward, another cutting groove 5 is formed so that the cutting projection 6 is formed with a spacing of the cutting projection interval D2 from the previo usly formed cutting groove 5.

By performing the above process repeatedly, the cutting grooves 5 wherein the const ant interval D 1 and the constant depth H are maintained may be formed on the scribe line 2 of the cone type scriber cutter 1, so that the cutting projections 6 with the constant cutting projection interval D2 are formed between the adjacent cutting grooves 5.

According to the present invention, the cutting grooves 5, which are maintained as d esirable surface features, can be precisely formed on the scribe line 2 of the cone type scrib er cutter 1, which is formed in the normal type, by means of the electric discharge machini

ng type cutting groove making apparatus 10 using the CNC or the laser type cutting groove making apparatus 20 using the laser.

The cone type scriber cutter 1, wherein the cutting grooves 5 are precisely formed by the electric discharge machining type cutting groove making apparatus 10 or the laser typ e cutting groove making apparatus 20, is mounted on a holder member 30, which is installe d in the head 51 of the nonmetal cutting apparatus 50, as shown in Fig. 6, so that the cutter is used to form the scribe line on a workpiece 40.

Mounting the cone type PCD scriber cutter 1 according to the present invention to th e holder member 30 is performed as follows.

With each of scriber holders 37 connected to each of both apexes of the cone type sc riber cutter 1, the respective scriber holders 37 are tightly fitted into mounting grooves, wh ich are formed in the lower ends of supporting plates 34,35 of the holder member 30. Th en, under the tightly fitted state, by inserting an engaging bolt (not concretely shown) into an engaging hole 36 formed in the supporting plates 34,35, and engaging the bolt with a th read portion 36-1, the cone type scriber cutter 1 is installed in the holder member 30.

The holder member 30 is used with the cone type scriber cutter 1 mounted in the hol der member 30, wherein an axial rod 32 is inserted into a cutting apparatus, and then a gen eral bolt (not concretely shown) is inserted into a mounting hole 33 of a mounting portion 31 so as to be engaged with a thread portion 33-1, so that the installation is completed by fi xing the mounting portion 31 to the cutting apparatus integrally.

With the cone type scriber cutter 1 according to the present invention installed in the cutting apparatus such as the nonmetal cutting apparatus 50, the cone type scriber cutter 1 is in contact with the workpiece 40, such as a TFT-LCD or glass. Then, the scribing pro cess is performed by applying a cutting pressure to the cone type scriber cutter 1 and straig htly moving it. And during the scribing process, the line scribed on the surface of the work piece 40 results in formation of crack. Thus, the workpiece 40 can be easily and rapidly c ut, and the cut surface maintains a clear and smooth state.

The cone type scriber cutter 1 according to the present invention can be mounted at a n exact position since the scriber holder 37 is used. Furthermore, by adjusting the engagi ng bolt (not concretely shown) engaged with the engaging hole 36 of the supporting plates

34,35, a contact area with the scriber holder 37 can be controlled, and supporting pressure (compressing force), i. e. , adhering state can be also controlled so that a vibration of the cut ting apparatus (tool) caused from wear is prevented.

In particular, since the cone type scriber cutter 1 according to the present invention i s engaged into the mounting grooves of the supporting plates 34,35 by tight fit when moun ted in the holder member 30, the scriber holder 37 can be replaced over ten times in the sa me holder member 30. Also, since the scriber holder 37 is used to mount the cone type sc riber cutter 1, as compared with using a cemented carbide scriber holder, a vibration of the cutting apparatus caused from rapid wear can be considerably decreased, the number of ti mes of adjusting according to the adhesion of a gap can be also decreased, eliminating a w aste of time, and a life of the holder can be lengthened over ten times more than that of a ce mented carbide scriber holder.

Industrial Applicability As described above, in the cone type scriber cutter 1 according to the present inventi on, the conical surfaces are integrally formed on both outer sides of the edge surfaces form ed on both side of the scribe line, and in particular, the cutting grooves with a constant inte rval and a constant depth are precisely formed on the scribe line by means of an electric dis charge machining type cutting groove making apparatus or a laser type cutting groove mak ing apparatus. Thus, a pressure per unit area of the scribe line portion, wherein the pressu re is transmitted to the workpiece, can be increased so that vertical deeper cracks are obtain ed when the outer diameter of the scribe line is reduced and the same cutting pressure is ap plied. Furthermore, when the scribing process is performed, horizontal cracks on the wor kpiece are minimized and vertical deep cracks are easily generated with small pressure, so that the workpiece can be completely broken with the cut surface clear so that a continuous /non-continuous piece (chipping) is not generated when the workpiece is cut. Thus, a qua lity and productivity of the workpiece can be improved. In addition, since the apexes of t he conical surfaces formed on both sides are engaged by using the holders, wear of an axis and vibration of a tool can be prevented, and a life of the tool can be also lengthened.