KR100807533B1 - Improved drill tool - Google Patents

Abstract

An improved drill tool is provided to increase life span and prevent abrasion of a body part due to a chip discharged during cutting by extending the length and thickness of a cutting tip. An improved drill tool comprises a drill main body(110), and a cutting tip(130). The drill main body, which is integrally extended from a bag part(112), has a body flute groove(116) at the outer periphery, and a body part(114) where a tip sheet(118) is formed at the front end. The cutting tip is firmly welded on the tip sheet, and includes a thinning surface, and a relief surface at the body part to be ground with the body part. The cutting tip also consists of a margin surface, a tip flute groove, an outer margin surface, and a cutting edge. The sheet bottom(122) of the tip sheet with a V shape is extended to a rotation center line of the body part. The tip bottom(132) of the cutting tip mating to the sheet bottom is protruded with the V shape. The sheet bottom is narrowly extended with angles of 50 to 175 degrees from two ends of the sheet bottom toward the center part of the body part. The tip bottom is narrowly extended at the angles of 50 to 175 degrees from the two ends of the tip bottom to the outside of the tip bottom.

Description

IMPROVED DRILL TOOL}

1 is an exploded perspective view showing an exploded drill tool according to the present invention,

FIG. 2 is a perspective view illustrating a state in which a cutting tip is processed after mounting the cutting tip material shown in FIG. 1 to a drill body;

3 is a plan view of FIG.

4 is a view showing another embodiment of the cutting tip shown in FIG.

5 shows the chip discharging direction when used after regrinding of an improved drill, and

6A and 6B show a conventional drill tool.

Explanation of symbols on the main parts of the drawing

100: improved drill tool 110: drill body

112: bag portion 114: body portion

116: body flute groove 118: tip sheet

120: sheet side 122: sheet bottom surface

130: cutting tip 132: tip bottom surface

134: clearance side 135: pickled

136: tip side 138: tip flute groove

140: outer margin margin 142: protrusion

144: oil hole

The present invention relates to a drill tool, and more particularly, by improving the body portion of the drill body correspondingly to the cutting tip while increasing the length and thickness of the cutting tip, the length of the cutting tip is shortened by regrinding the cutting tip as well as new. The present invention relates to a drill tool capable of preventing abrasion wear of the body part caused by chips discharged during cutting, even if it is lost.

In general, cutting tools are mainly iron-based. It is a tool used for cutting nonferrous metals and nonmetallic materials, and is usually mounted on a machine tool to perform cutting in order to process a workpiece into a desired shape. This cutting tool consists of a cutting tip with pickled and a body to hold the cutting tip.

There are two ways to cut metal using cutting tools. First, cutting is performed by contacting the pickled part of the cutting tool that is fixed to the rotating workpiece. After fixing a tool, ie, a cutting tip, to a machine tool using a holder for a tool, the workpiece is processed into a desired shape by contacting or penetrating a workpiece which is fixed in advance while rotating the cutting tool.

The drill tool belongs to both of the above metal cutting methods, and drills the workpiece by rotating the workpiece or rotating the drill.

The drill tool described above uses an integrated solid drill tool consisting of a drill body, a flute groove, and a cutting edge made of a single material. However, as a method for improving tool life and reducing manufacturing cost, a separate carbide cutting tip (hereinafter, “ It is being improved as a drill tool by applying a cutting tip ”, and such improvement method is a brazing type and an indexable type depending on a method of fixing the cutting tip to the drill body. The brazing type is to fix the cutting tip permanently by brazing welding the cutting part to the part of the body, and the indexable type is to mount and detach the cutting insert to the body by using the fixing means provided in the body.

The indexable type drill tool can be easily replaced with a new cutting insert in a short time when the cutting insert's pickling reaches the end of its life, which has the disadvantage that the brazing type drill tool has to be regrinded for a long time. There is an advantage that can be solved.

However, since the indexable drill tool has to be rotated about the same axis as the drill body and cutting insert, it is difficult to set the center of rotation precisely. Therefore, a separate centering device is provided. There is a problem in that the chip is caught in the means and the screw or separate complex fastening structure easily breaks the body flute part under strong drilling processing conditions. Due to the problems described above, in the workplace, not only an indexable drill to which an exchangeable cutting insert is applied, but also a brazing type for welding a cutting tip to the drill body is used in parallel.

6A and 6B, in the case of a drill of welding in which the cutting tip 10 is welded to the body part 20 of the drill body, the discharged chip e is outside the body flute groove 22. There was a problem that the drill life is shortened by causing friction with the body portion 20 at the neck and the central portion h to damage the body portion 20 (see FIG. 6B). This problem is caused by the fact that the tip of the cutting tip 20 is thin and the chip is discharged due to excessive friction with the outer diameter of the body flute groove 22, and the length of the cutting tip 10 is regrinded several times. Since the length of the center of the tip flute groove 12 of the cutting tip 10 is also shortened when it is shortened, the cutting chip e and the body part 20 which are discharged in the center direction to the tip flute groove 12 of the cutting tip 10. This is a case where severe wear occurs in the body portion 20 and the body flute groove 22 center due to excessive friction with the center of the body pull flute groove 22. In order to prevent wear of the outer flute of the body flute groove 22, a problem may be solved by increasing the thickness of the cutting tip 10. However, by increasing the thickness of the cutting tip 10, the thickness of the sheet side surface portion 24 supporting rigidity is increased. It can be manufactured because it is relatively thin, but can not be applied due to breakage during use, and in order to prevent abrasion of the center of the body flute groove 22 generated during regrinding, the length of the cutting tip 10 after regrinding is higher than a predetermined level. In this case, the number of regrinding is reduced to less than half, which increases the tool consumption, that is, the tool cost increases, making it difficult to apply.

The problem in this conventional welded drill is a fundamental problem that occurs because the shape of the cutting tip 10 in contact with the axial body seat portion 26 is a straight line is no further improvement.

The present invention has been made to solve the conventional problems as described above, an object of the present invention by improving the body portion of the drill body corresponding to the cutting tip while extending the length and thickness of the cutting tip, the new as well as the cutting tip Even if the length of the cutting tip is shortened by regrinding, it is possible to prevent frictional wear of the body part by the chips discharged during the cutting process, thereby providing a drill tool capable of extending the service life.

In order to achieve the object of the present invention as described above, the present invention,

An integral body extending from the bag and having a body flute groove formed on the outer circumferential surface thereof, the drill body having a body portion having a tip sheet formed at the tip, and a cutting tip firmly welded to the tip sheet, the grinding tip is ground together with the body portion. In the drill tool which is processed to form a thinning surface, a relief surface at the tip of the body portion, and to form a clearance surface, a tip flute groove, an outer margin surface, pickling at the cutting tip,

The seat bottom surface of the tip sheet has a V shape and extends on the center of rotation of the body portion, and the tip bottom surface of the cutting tip corresponding to the seat bottom surface protrudes in a V shape. Provide drill tools.

As described above, according to the present invention, by improving the body portion of the drill body corresponding to the cutting tip while extending the length and thickness of the cutting tip, even if the cutting tip is shortened by regrinding the cutting tip as well as new products Friction wear can be prevented by the chip which is discharged during cutting process, so the service life can be extended.

Hereinafter, a drill tool according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

1 is an exploded perspective view showing an exploded drill tool according to the present invention, Figure 2 is a perspective view showing a state in which the cutting tip is processed after mounting the cutting tip material shown in Figure 1 in the drill body, 3 is a plan view of FIG. 2.

1 to 3, an improved drill tool 100 according to the present invention is mainly provided with a drill body 110 mounted on an arbor (not shown) of a machine tool (not shown), and a drill body. It is provided with a cutting tip 130 that is processed after welding fixed to the front end portion (110).

First, the drill body 110 has a bag 112 and a body portion 114 integrally extending from the bag 112, the body portion 114 is a plurality of body flute groove 116 and the tip Sheet 118 is formed. The body flute groove 116 extends helically along the body portion 114, and the tip sheet 118 has a body portion 114 such that both ends thereof are connected to the body flute groove 116 at the distal end portion of the body portion 114. Is formed to extend from the front end of the bag portion 112 side.

The tip sheet 118 described above includes a sheet side surface 120 facing each other and a sheet bottom surface 122 connecting lower portions of the respective sheet side surfaces 120. The seat bottom surface 122 has a substantially V shape and extends narrowly along the body flute groove 116 onto the center of rotation CL of the body portion 114. The cutting tip 130 corresponding to the tip sheet 118 is welded to the tip sheet 118 of the drill body 110 formed as described above.

Cutting tip 130 is manufactured by using an alloy to perform the cutting process of ferrous or non-ferrous metal, welded to the tip sheet 118 of the cutting tip 130, and then used as it is by grinding the cutting tip 130 Alternatively, or in order to increase the wear resistance of the ground cutting tip 130 by using a PVD or CVD coating method to coat the ceramic-based coating is used.

The cutting tip 130 described above, that is, the cutting tip 130 in the state before grinding is manufactured in a square or partially roughed shape (see Fig. 1), the rear end of the cutting tip 130, the tip bottom surface 132 is formed, and the tip bottom surface 132 has a shape corresponding to the seat bottom surface 122 of the tip sheet 118, that is, a shape protruding in a substantially V shape. At this time, the seat bottom surface 122 and the tip bottom surface 132 has an angle θ of 50 to 175 degrees, preferably 90 to 140 degrees and extends narrowly.

When the cutting tip 130 is welded to the body portion 114 with the tip bottom surface 132 of the cutting tip 130 described above resting on the seat bottom surface 122 of the tip sheet 118, the cutting tip 130 130 and the tip of the body 114 are ground, respectively, the free end 134 and thinning surface 124 is formed at the tip of the cutting tip 130 and the tip of the body 114, respectively, the body flute On each tip side 136 of the cutting tip 130 exposed to the groove 116 side, a tip flute groove 138 is formed to be connected to the body flute groove 116, and the tip flute groove 138 and the clearance surface ( Pickling 135 is formed between the 134 and the outer peripheral surface 140 is formed on both ends of the cutting tip 130 while the relief surface 126 is formed at the front end of the body portion 114 (FIG. 2). Reference).

The tip flute groove 138 formed by the grinding of the cutting tip 130 is formed to have a radius of curvature Rt smaller than the radius of curvature Rb of the body flute groove 116 and the depth of the tip flute groove 138. Grinding (FDt) lower than the depth (FDb) of the body flute groove 116, so that the depth (FDt) of the tip flute groove 138 is formed lower than the depth (FDb) of the body flute groove 116, When the thickness T of the cutting tip 130 is thickened, the tip flute groove 138 is formed to protrude higher than the body flute groove 116, so that the chip (e) discharged during the cutting process is outside the body flute groove 116. It is discharged without friction with the neck and the central portion (h) can prevent the wear or damage of the body portion 114 (see Fig. 5). At this time, the thickness of the cutting tip 130 is formed to have a thickness (T) of 0.25 ~ 0.6 times, preferably, 0.35 ~ 0.5 times the diameter (D) of the body portion 114.

In addition, since the tip bottom surface 132 and the seat bottom surface 122 have a V shape, the length of the tip side surface 136 is elongated at the center of the cutting tip 130 so that the body flute groove 116 is formed. The length of the tip flute groove 138 is long in the center of the chip, and even if the cutting tip 130 is shortened due to the regrinding of the pickled 135, etc., the chip discharged during drilling is the central part of the body flute groove 116 as in the prior art. Since it is not rubbed in the center of the tip flute groove 138, it is possible to prevent damage to the body flute groove 116. That is, the number of regrinding can be increased 2 to 3 times or more as compared with the conventional weld type drill in which the seat bottom surface 122 is provided in a horizontal plane, and the life of the drill after regrinding can be maintained as new.

4 is a view showing another embodiment of the cutting tip shown in FIG.

Referring to FIG. 4, the cutting tip 130 is applied when the outer diameter of the drill body 110 is small to prevent friction of the body flute groove 116 by the discharge chip while maintaining the rigidity of the body portion 114. As shown in FIG. 3, each tip side 136 of the cutting tip 130 has an oblique angle L-shape to have a protrusion 142, and the sheet side side 120 Can be manufactured to correspond to the tip side (136). In this case, since the protrusion 142 protrudes and becomes thicker than the body flute groove 116, the stiffness of the body part 114 may be maintained while preventing the discharged chip from rubbing against the body flute groove 116. At this time, the thickness (T ') of the protrusion 142 formed on the tip side surface 136 is formed to have 0.3 ~ 0.7 times the diameter (D) of the body portion 114, the thickness (t) of the tip side surface 136 Is formed to have a 0.2 ~ 0.5 times the diameter (D) of the body portion 114.

Meanwhile, in order to improve the performance of the drill tool 100, various types of internal oil holes 144 for supplying cutting oil to the distal end of the drill body 110 may be formed.

As described above, the improved drill tool 100 according to the present invention extends the length of the cutting tip 130 and thickens the thickness of the cutting tip 130 while the tip sheet 118 of the body portion 114. By improving to correspond to the cutting tip 130, the chip discharged during the cutting operation is discharged without interfering the outer diameter portion in the body flute groove 116 of the body portion 114, the length of the cutting tip 130 is regrind Even when shortened, the discharge chip is discharged while curling and rubbing in the center of the tip flute groove 138 of the cutting tip 130 to prevent the center of the body flute groove 116 from being damaged, thereby preventing wear of the body flute groove 116. You can prevent it.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the invention described in the claims. You will understand.

Claims (6)

An integrally extending from the bag and the body flute groove is formed on the outer circumferential surface and a drill body having a body portion having a tip sheet formed at the distal end, and a cutting tip firmly welded to the tip sheet, the gripping tip is the body portion In the drill tool to be ground with a grinding surface to form a thinning surface, a relief surface at the tip of the body portion, and to form a clearance surface, tip flute groove, outer peripheral margin, pickling on the cutting tip, The seat bottom surface of the tip sheet has a V shape and extends on the center of rotation of the body portion, and the tip bottom surface of the cutting tip corresponding to the seat bottom surface has a V shape. Improved drill tool, characterized in that protruding. According to claim 1, wherein the seat bottom surface is narrowly extended at an angle of 50 ~ 175 degrees from both ends of the seat bottom surface to the central side of the body portion, the tip bottom surface at both ends of the tip bottom surface An improved drill tool, characterized in that it extends narrowly with an angle of 50 ~ 175 degrees to the outside of the bottom surface. delete The improved drill tool according to claim 1, wherein the cutting tip has a thickness of 0.25 to 0.6 times the diameter of the body portion. The method of claim 1, wherein the radius of curvature of the tip flute groove of the cutting tip is smaller than the radius of curvature of the body flute groove and the depth of the tip flute groove is formed lower than the depth of the body flute groove so that the tip flute groove is the body An improved drill tool, characterized in that it projects more than the flute groove. The method of claim 1, wherein the cutting tip is to produce each of the tip side to have an oblique angled L-shaped protrusion so that the protrusion protrudes toward the body flute groove side, both sides of the tip side Improved drill, characterized in that the protruding thickness of the protrusion is formed to have a 0.3 ~ 0.7 times the diameter of the body portion and the thickness of the tip side can be formed to have a 0.2 ~ 0.5 times the diameter of the body portion tool.

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