JP3601953B2 - Core drill with seamer - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core drill with a seamer capable of drilling a hole and chamfering an edge of the hole when drilling a hole in a hard brittle material such as a glass plate.
[0002]
[Prior art]
When drilling a hole in a glass plate, chipping occurs at the edge of the hole.As a countermeasure, use a core drill equipped with a chamfering tool called a seamer and chamfer the edge at the same time as drilling. ing.
[0003]
Conventionally, as a core drill with a seamer generally used, for example, there is a drill as shown in FIG. The core drill 30 with seamer shown in FIG. 3A is obtained by separately manufacturing the seamer portion 31 and the drill portion 32 and then combining them. However, in the case of the core drill 30 with a seamer, the side surface of the core drill portion 32 wears as the drilling process is repeated, and the gap 33 between the core drill portion 32 and the seamer portion 31 becomes large. Are likely to be clogged, causing chipping.
[0004]
In order to prevent the occurrence of such chipping, a core drill 34 with a seamer as shown in FIG. 3B has been developed. The core drill 34 with a seamer is also one in which the drill portion 35 and the seamer portion 36 are separately manufactured and combined. In the case of the structure as shown in FIG. 3B, the fitting between the drill portion 35 and the seamer portion 36 is not sufficient. Because it is difficult, not only processing takes a long time, but also the yield is poor.
[0005]
Further, a diamond seamer capable of preventing the occurrence of a gap between the drill portion and the seamer portion is disclosed in Japanese Utility Model Laid-Open Publication No. 63-12875, etc., but also in this seamer, when the side surface of the drill portion is worn, There is a problem that a gap is easily generated and it takes time to mount.
[0006]
Therefore, in order to solve such a problem, as shown in FIG. 3C, a core drill 40 provided with a seamer in which a drill portion 38 and a seamer portion 39 are manufactured by an integral molding method has been developed. Here, the integral molding method is a method in which the base metal 37 holding the drill portion and the seamer portion is made into one, and the grindstones forming the drill portion 38 and the seamer portion 39 are simultaneously molded.
[Problems to be solved by the invention]
However, in the case of the core drill 40 with a seamer as shown in FIG. 3C, the tip of the base metal 37 has a step-like shape in order to form the seamer portion 39 on the outer peripheral side of the drill portion 38. Therefore, in order to integrally form the drill portion 38 and the seamer portion 39 in the manufacturing process, a mold having a complicated shape is required, and much labor is required for manufacturing the mold.
[0008]
In addition, since the drill portion 38 and the seamer portion 39 have different processing purposes depending on the respective portions, the grain sizes of the abrasive grains constituting the respective portions are different. A single base metal was formed side-by-side and filled simultaneously with a bond containing abrasive grains of different grain sizes forming the seamer and drill parts, so it was difficult to form a boundary, and it was composed of fine abrasive grains Coarse abrasive grains forming the drill portion 38 may be mixed into the seamer portion 39. As described above, when the glass plate is drilled by a core drill with a seamer in which the coarse abrasive grains forming the drill portion 38 are mixed in the seamer portion 39, scratches and large chipping occur in the chamfered portion, resulting in processing failure.
[0009]
Therefore, an object of the present invention is to provide a core drill with a seamer that does not require a complicated mold, does not contain abrasive grains, and has an excellent chipping prevention function during drilling.
[0010]
[Means for Solving the Problems]
In order to solve the above-described problems, a core drill with a seamer of the present invention includes a base metal having a cylindrical end portion, and a seamer portion and a drill portion formed on the front end surface of the base metal in an axially stacked state. And a slope portion having a diameter larger than the outer diameter of the drill portion is provided in the seamer portion. With such a configuration, a seamer portion and a drill portion are formed on the tip end surface of the base metal in a stacked state in the axial direction, and the seamer portion has a structure including a slope portion having a diameter larger than the outer diameter of the drill portion. Drilling is performed by a drill portion, and in parallel with this, chamfering by a slope portion can be performed.
[0011]
Moreover, in the core drill with a seamer of the present invention, since the seamer portion and the drill portion are formed by being laminated in the axial direction of the base metal, the boundary surface is in a positional relationship crossing the axial direction. Therefore, even when the outer peripheral surface of the drill portion is worn down due to repeated drilling and the outer diameter is reduced, no gap is generated at the boundary surface between the drill portion and the seamer portion, and glass chips are clogged in the gap. No chipping occurs.
[0012]
Further, since the seamer portion and the drill portion have a structure formed in a laminated state on the front end surface of the base metal, the front end portion of the base metal 37 is stepped or the like as in a core drill 40 with seamer shown in FIG. No complicated mold is required in the manufacturing process. Further, in the case of the core drill with a seamer of the present invention, in the manufacturing process, after filling the bond containing the abrasive grains for the seamer part on the tip end surface of the base metal held in the mold, forming the seamer original part by pressing. The bond containing the abrasive grains for the drill portion is filled so as to be in intimate contact with the Cima prototype portion, and the pressure is applied to form the drill prototype portion. Thereafter, sintering can be performed. Is clear, and no abrasive grains are mixed between the two.
[0013]
In the case of the core drill 40 with a seamer shown in FIG. 3C, a bond containing abrasive grains having different grain sizes constituting the seamer portion and the drill portion is arranged side by side with respect to one base metal having a stepped tip. Incorporation of abrasive grains may occur because they must be filled and simultaneously molded, but in the case of the present invention, the tip contains abrasive grains constituting a seamer portion on a base metal having a flat shape. After filling the bond, a clear boundary is formed by pressurizing, so that even after the bond containing the abrasive grains constituting the drill portion is filled and pressurized, the mixing of the abrasive grains does not occur .
[0014]
On the other hand, the core drill with a seamer of the present invention has a structure in which a slope portion having a diameter larger than the outer diameter of the drill portion is provided in the seamer portion. The part can be formed by subjecting the part to machining such as electric discharge machining or polishing. As described above, since a core drill with a seamer having a predetermined shape is formed by machining after sintering, a complicated mold close to the final product shape is not required in the molding process, and only one type of mold is required. . In addition, by subjecting the original seamer portion and the original drill portion to polishing and electrical discharge machining after sintering, it is possible to form a core drill with a seamer having excellent dimensional accuracy and a conspicuous state of the grindstone.
[0015]
In addition, in the case of electric discharge machining, pressure is not applied to the workpiece, and it is possible to easily perform shaping over a wide range without changing the physical properties of the bond.In the case of polishing, shaping can be performed in a relatively short time. It can be carried out. Here, “shaping” refers to a processing step for adjusting the Cima original part and the drill original part to the final shape as a core drill with a seamer.
[0016]
Further, in the core drill with a seamer of the present invention, the grain size of the abrasive grains forming the drill portion can be set to # 80 to # 120, and the grain size of the abrasive grains forming the seamer portion can be set to # 140 to # 200. In a core drill with a seamer, since the processing purpose is different between the drill part and the seamer part, it is necessary to make the grain sizes of the abrasive grains constituting the drill part and the seamer part different from each other. That is, it is necessary to adjust the grain size of the abrasive grains forming the drill portion and the seamer portion so that the wear speed of the drill portion and the wear speed of the seamer portion match, but the grain size of each portion is set to such a range. As a result, when drilling of a glass plate or the like is repeatedly performed, the drill portion and the seamer portion are equally worn, so that the so-called one-side loss is eliminated and the life is made uniform.
[0017]
In the case where the grain size of the abrasive grains constituting the drill portion is coarser than # 80, the processing speed increases, but chips which cannot be removed at the seamer portion occur. On the other hand, in the case of # 120 or smaller, the processing speed becomes slow and the abrasion becomes large, so that problems such as a loss of balance with the seamer portion are likely to occur. Further, when the grain size of the abrasive grains constituting the seamer portion is coarser than # 140, the quality of the chamfered portion is reduced. Problems such as a loss of balance tend to occur.
[0018]
Further, the core drill with a seamer of the present invention is characterized in that the degree of concentration of the drill portion is larger than the degree of concentration of the seamer portion. Here, the degree of concentration is expressed as a ratio with 100 when the content of diamond or CBN occupying 4.4 ct (= 0.2 g) per 1 cm ³ of the volume of the abrasive grain layer is 100. If the concentration of the drill and the seamer is the same, during the machining operation, the wear rate of the drill will be higher than that of the seamer, causing a loss, but the concentration of the drill will be greater than the concentration of the seamer. By doing so, the wear rates of the drill portion and the seamer portion become equal, so that there is no loss and the life can be made uniform.
[0019]
In this case, it is desirable that the concentration of the drill portion is about 10 to 50 greater than the concentration of the seamer portion, so that even when the machining operation is repeatedly performed, the drill portion and the seamer portion are equally worn and degraded. Does not occur and the life is made uniform.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a partially cutaway side view showing an embodiment of a core drill with a seamer, and FIG. 2 is an explanatory diagram showing a manufacturing process of the core drill with a seamer shown in FIG.
[0021]
As shown in FIG. 1, a core drill 10 with a seamer according to the present embodiment is formed by stacking a base metal 13 having a cylindrical end portion on a front end surface 13 f of the base metal 13 in an axial direction 13 a of the base metal 13. A seam portion 11 and a drill portion 12, and a slope portion 11 a having a diameter larger than the outer diameter of the drill portion 12 is provided in the seamer portion 11.
[0022]
With such a configuration, the seamer portion 11 and the drill portion 12 are formed in a stacked state in the axial direction 13 a on the tip end surface 13 f of the base metal 13, and the seamer portion 11 has a slope portion whose diameter is larger than the outer diameter of the drill portion 12. Since the structure is provided with 11a, drilling can be performed by the drill portion 12 and, in parallel with this, chamfering by the slope 11a can be performed.
[0023]
Moreover, in the core drill 10 with a seamer, since the seamer portion 11 and the drill portion 12 are formed by being laminated in the axial direction 13a of the base metal 13, the boundary surface 20 has a positional relationship such that it crosses the axial direction 13a. is there. Therefore, even when the outer diameter of the drill portion 12 is reduced due to wear of the outer peripheral surface of the drill portion 12 due to repetitive drilling, no gap is generated at the boundary surface 20 between the drill portion 12 and the seamer portion 13, and the glass chips It is possible to prevent chipping or the like from occurring due to clogging of the gap.
[0024]
Further, since the seamer portion 11 and the drill portion 12 have a structure formed in a laminated state on the front end face 13f of the base metal 13, the front end portion of the base metal 37 is cut like a core drill 40 with seamer shown in FIG. There is no need to make steps, and no complicated mold is required in the manufacturing process.
[0025]
Furthermore, in the core drill 10 with a seamer of the present embodiment, the grain size of the abrasive grains forming the drill portion 12 is set to # 120 which is within the range of # 80 to # 120, and the degree of concentration is set to 75, thereby forming the seamer portion 11. When the grain size of the abrasive grains was set to # 170 within the range of # 140 to # 200 and the degree of concentration was set to 50, when drilling of a glass plate or the like was repeatedly performed, the drill portion 12 and the seamer portion 11 were equivalently formed. Wear and loss did not occur, and the life of both members could be made uniform.
[0026]
Next, a manufacturing process of the core drill with seamer 10 shown in FIG. 1 will be described with reference to FIG.
[0027]
First, as shown in FIG. 2A, a tip 11 f of a base metal 13 held in a mold 14 is filled with a bond 11 b containing abrasive grains for a seamer portion, and after pressurizing, a bond for a drill portion is formed. The bond 12b containing grains is filled and pressurized. Then, when sintering is performed by a hot press method, as shown in FIG. 2B, a seamer prototype 11c and a drill prototype 12c stacked in the axial direction 13a are formed on the tip end surface 13f of the base 13. Is done.
[0028]
As described above, after filling and pressurizing the bond 11b, filling and pressurizing the bond 12b, and then performing sintering, the boundary between the drill original part 12c and the seamer original part 11c becomes clear, and the There is no mixing of abrasive grains.
[0029]
Next, as shown in FIG. 2 (c), electric discharge machining is performed on the Cima original part 11c and the drill original part 12c to remove the X portion, and as shown in FIG. Thus, the slope portion 11a having a diameter larger than the outer diameter of the drill portion 12 is formed, and the drill 10 with the seamer adjusted to the final shape is obtained.
[0030]
As described above, the core drill with seamer 10 of the present embodiment has a structure in which the inclined portion 11a having a diameter larger than the outer diameter of the drill portion 12 is provided in the seamer portion 11, but the original drill formed after sintering is completed. Since the part 12c and the Cima prototype part 11c are formed by performing electrical discharge machining, a complicated mold close to the final product shape is not required in the molding process, and only one kind of mold is required.
[0031]
In addition, by subjecting the seam prototype 11c and the drill prototype 12c to electric discharge machining after sintering, it is possible to form the core drill with seamer 10 having excellent dimensional accuracy and outstanding condition of the grindstone. In the case of electric discharge machining, pressure is not applied to the workpieces such as the seam prototype 11c and the drill prototype 12c, and a wide range of shapes can be easily formed without changing the physical properties of the bond.
[0032]
In addition, it is also possible to obtain the drill 10 with the seamer adjusted to the final shape by performing polishing on the seam prototype 11c and the drill prototype 12c to remove the X portion. In the case of polishing, shape formation can be performed in a relatively short time.
[0033]
Since the embodiment shown in FIG. 2 is an example for manufacturing the drill 10 with a seamer shown in FIG. 1, for the forming step, the sintering step or the processing step after sintering, other steps may be adopted. Can be.
[0034]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0035]
(1) A base metal having a cylindrical end portion, a seamer portion and a drill portion formed on the front end surface of the base metal in a stacked state in the axial direction of the base metal, and the seamer portion has an outer diameter of the drill portion. By providing the slope part with an enlarged diameter, drilling can be performed by the drill part, and in parallel with this, chamfering by the slope part can be performed. Also, since the seamer portion and the drill portion are formed by laminating in the axial direction of the base metal, and the boundary surface is in a positional relationship crossing the axial direction, the outer diameter of the drill portion is worn and the outer diameter is reduced. However, no gap is generated at the boundary surface between the drill portion and the seamer portion, and chipping or the like does not occur due to the chips of the glass clogging the gap.
[0036]
(2) Since the seamer portion and the drill portion have a structure formed in a stacked state on the tip end surface of the base metal, the tip end portion of the base metal does not need to be stepped, and a complicated mold is required in the manufacturing process. And not. In addition, since the bond containing abrasive grains having different grain sizes constituting the seamer portion and the drill portion is sequentially laminated and formed in the axial direction of the base metal, the boundary between the drill portion and the seamer portion becomes clear, and the abrasive grain between the two becomes clear. Does not occur.
[0037]
(3) In the structure in which the slope portion with a diameter larger than the outer diameter of the drill portion is provided on the seamer portion, the original drill portion and the original seamer portion formed by sintering are subjected to machining such as electric discharge machining or polishing. Therefore, in the molding process, a complicated mold close to the shape of the final product is not required, and only one kind of mold is required.
[0038]
(4) By setting the grain size of the abrasive grains constituting the drill portion to be in a range of # 80 to # 120 and the grain size of the abrasive grains constituting the seamer portion to be in a range of # 140 to # 200, drilling a glass plate or the like can be performed. When repeated, the wear rates of the drill portion and the seamer portion become equal, so that no loss occurs and the life can be made uniform.
[0039]
(5) By making the degree of concentration of the drill part larger than the degree of concentration of the seamer part, the wear rates of the drill part and the seamer part during the machining operation can be made equal, so that the one-sided wear does not occur and the life is shortened. Can be made uniform.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view showing an embodiment of a core drill with a seamer.
FIG. 2 is an explanatory view showing a manufacturing process of the core drill with a seamer shown in FIG. 1;
FIG. 3 is a sectional view showing a conventional core drill with a seamer.
[Explanation of symbols]
Reference Signs List 10 core drill with seamer 11 seamer 11a slope 11b, 12b bond 11c seamer original part 12 drill part 12c drill original part 13 base metal 13f tip surface 13a axial direction 14 die 20 boundary surface

Claims (1)

A tip metal having a cylindrical shape at the tip end, and a seamer portion and a drill portion formed in a stacked state in an axial direction of the tip metal on the tip surface of the metal stem, and the outer diameter of the drill portion is provided at the seamer portion. A slope part having a larger diameter is provided , and the grain size of the abrasive grains constituting the drill portion is # 80 to # 120, and the grain size of the abrasive grains constituting the seamer portion is # 140 to # 200. A core drill with a seamer, characterized in that it is larger than the degree of concentration of the seamer.

Images