JP3103139U - Structure of disposable drill bit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disposable drill bit which has a continuous cutting function, solves a loss of a cutting edge, improves fixing and supporting strength of a center bit blade, enhances cutting ability, and is easy to manufacture and reduces cost. Provide structure.
SOLUTION: In addition to a center bit 41 having a center hole cutting and locating function, a center bit cutting piece 40 has an extended cutting piece 42 having a hole cutting function. By providing the V-shaped cutting blades 411 and 412 of the center bit 41 with a continuous cutting function, the cut chips do not accumulate between the cutting blade 411 and the extended cutting blade 42, and the extended cutting blade Chips do not accumulate between the inner cutter 51 and the center bit 40 because there are multiple cutting portions between the inner cutter 51 and the inner cutter 51. A notch is provided between the extension cutting edge 42 and the cutting edge of the stop bit to disperse cutting stress and prevent breakage of the cutting edge. The center bit cutting piece 40 and the center cutting piece stand 31 are formed with a dovetail shape of a slope corresponding to each other, so as to increase the support strength of the center bit cutting piece 40 and increase the cutting ability.
[Selection diagram] Fig. 1

Description

  The present invention relates to the structure of a disposable drill bit.

  A known disposable drill bit is a single-piece disposable drill bit 10 manufactured by a world-renowned manufacturer, Kenamitel Hatell Co., as shown in FIG. The mouth 13 is provided. This has the effect of blocking the entry of chips and reducing the accumulation of chips. However, since the cutting edge and the bit edge 12 cannot be continuously cut at the portion 13 of the scrap stopper, the iron scrap concentrates here. In addition, it becomes slower as it approaches the center bit edge 12. Conversely, the cutting force and pressure are further increased. For this reason, considerable pressure and accumulated debris collect at the corner of the debris stop 13. Then, a breakage phenomenon occurs at the corner of the dust stopper 13, and the blade 11 is damaged and cannot be used, thereby increasing the cost of the blade.

  FIG. 9 shows another type of disposable drill bit 20 having a center bit, which is a different type manufactured by Kenamitel-Hatell Co., Ltd. The cutting edge piece at the end of the bit comprises a center bit 21, an inner blade 22, and an outer blade 23. And all have a disposable construction. In this type of cutting blade, debris easily concentrates particularly on both side cutting edges of the center bit 21 and adjacent portions of the inner blade 22 and the outer blade 23, and presses the cutting edge (see a and b indicating portions). In addition, since the rotation speed of this portion is low and the cutting resistance is large, the cutting edge is fragile. In particular, the point indicated by the arrow a is the end of the oblique blade of the center bit 21 and the corner adjacent to the inner blade 22. It is. The cutting stress is concentrated at this corner, and a breakage phenomenon is likely to occur. Furthermore, the cost of the center bit 21 of this type is high, which increases the production costs.

  The problems to be solved by the present invention are that continuous cutting cannot be performed and the cutting edge is easily damaged, so that the cost is high and the competitiveness is weak. Further, since the fixing and supporting strength of the center bit blade is low, the cutting ability is not improved.

  Therefore, the present invention has been made to solve the above-mentioned problems, and has a continuous cutting function, solves the loss of the cutting edge, and improves the fixing and supporting strength of the center bit cutting piece, thereby improving the cutting ability. It is an object of the present invention to provide a disposable drill bit structure that is enhanced, simple to manufacture and low in cost.

  In order to achieve the above-mentioned object, the structure of the disposable drill bit according to the present invention is such that an extended cutting edge formed integrally with the center bit cutting piece is formed, and the extended cutting edge increases the cutting area of the center bit cutting piece. The cuts extend to prevent chip accumulation. A notched cut is provided between the extended cutting edge and the cutting bit of the stop bit to disperse cutting stress and prevent breakage of the cutting edge. The center bit cutting piece and the center cutting piece base are formed with a dovetail shape of a slope corresponding to each other, and the most main feature is to increase the supporting strength of the center bit cutting piece and increase the cutting ability.

The structure of the disposable drill of the present invention has the following advantages.
The center bit cutting piece has a central bit and an extended cutting piece, which is the first invention of the present invention. Accordingly, iron chips do not accumulate on the cutting edge, and damage to the cutting edge is prevented, so that the cutting function and efficiency are improved.

  The center bit blade is a dovetail-shaped bevel, and has good support strength of the center bit blade by being installed in the dovetail-shaped tank of the center blade. In this structure, the center cutting piece is installed in the center cutting piece base in a fitting manner, and is easily and easily replaced. Further, the center bit cutting piece has good cutting strength and the cutting ability is enhanced.

  There is a slight deviation between the screw hole installed on the center piece of the drill and the recess of the center bit piece, so that when the center bit piece is tightened, it moves slightly, It is even tighter and has a perfect locking function.

By installing a support blade, it is possible to carry out a deep hole drill.
The center bit cutting piece is provided with an inner blade and an outer blade, which is practical in response to changes in drill size.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the embodiment of the present invention, the center bit blade has a continuous cutting function to solve the accumulation of chips, prevent breakage of the cutting edge, and enhance the cutting function. This was achieved by molding the extended cutting edge.

  For the purpose of increasing the support strength and localization force of the center bit blade and receiving the cutting pressure and torsion force of the center bit blade, a dovetail type tank is formed on one side of the center bit base, This was achieved by fitting a bit blade.

  When the two dovetail slopes of the center bit blade and the dovetail-shaped tank formed on both sides of the center blade piece and the inclined side are screwed in, the purpose of tightening firmly and positioning is the purpose of the screw on the center bit blade piece. This was achieved by providing a slight offset between the hole and the recess of the center bit blade.

  As shown in FIGS. 1 and 2, in the embodiment of the present invention, a center blade 31 is installed at the center position of the end of the drill bit 30, and a center bit blade 40 is fixed thereto. Corresponding blade storage tables 32 and blade storage tables 33 are installed on both sides of the center blade piece base 31, and the inner blade 51 and the outer blade 52 are fixed thereto.

  The center bit blade 40 has an extended blade 42 integrally formed on both sides of the center bit 41, and an inclined side 45 formed on the uppermost one side near the center bit blade 40. On the other side, a slope 46 is formed parallel to the central axis and in the shape of a dovetail.

  An inclined dovetail-shaped tank 311 is formed on one side surface of the center cutting piece base 31 of the drill bit 30, and an inclined side 312 is formed on the other side, and corresponds to the center bit cutting piece 40. A screw hole 313 is formed in the center blade piece base 31. As shown in FIGS. 1 and 4, the screw hole 313 corresponds to the concave hole 44 of the center bit blade 40, and the center of the screw hole 313 is slightly raised. It is 0.05 mm.

An extension blade piece integrally molded with the center bit blade piece will be described.
(Resolving chip accumulation)
As shown in FIGS. 2 and 3, the central bit blade 40 is formed with an integrally formed extended blade 42. The center bit blade 40 has a center bit 41 having a center hole cutting and localizing function, and an extension blade 42 having a hole cutting function. That is, the extended blade piece 41 has a cutting function that is the same function as the inner blade. The purpose is to provide a continuous cutting function for both V-shaped cutting blades 411 and 412 of the center bit 41, so that the cut chips do not accumulate between the cutting blade 411 and the extension blade piece 42. In addition, since the extended cutting piece 42 and the inner cutter 51 have multiple cutting portions, chips do not accumulate between the inner cutter 51 and the center bit 40. Therefore, there is no friction generated at the cutting edge and no damage occurs, and no cutting resistance occurs. Further, the cutting edge of each blade always keeps the cutting edge, so that the breakage phenomenon does not occur in normal use. As a result, the cutting operation is performed smoothly, the service life of the blade is extended, the number of times of replacement of the blade is reduced, and the manufacturing cost is reduced.

(About the high strength structure of the bit center blade pedestal)
As shown in FIG. 1, the shape of the center blade piece base 31 is formed corresponding to the shape of the center bit blade piece 40. One side corresponds to a dovetail-shaped tank 311 having a slope and a birdtail-shaped slope 46 of a center bit blade 40, and another side is provided with an inclined side 312. Fit into one stand 31. As shown in FIG. 5, when the center bit blade 40 is subjected to stress by cutting, the cutting resistance force (arrow portion) generated by the bottom extension blade 42 is the slope 46 portion of the center bit blade 40 in a dovetail shape. With the support of the tank 311, the dovetail-shaped tank 311 becomes a part of the drill body. For this reason, the dovetail-shaped tank 311 has the strength that the center bit blade 40 withstands cutting stress. Further, the cutting resistance generated on the other extended blade 42 has a support function generated from the center blade base 31 and the inclined surface 312, and the cutting stress of the center bit blade 40 does not concentrate on the fixed screw 47. Further, since the dovetail-shaped tank 311 supports, the cutting strength of the center bit blade 40 is improved by the high cutting resistance, and the cutting ability is also increased.

(Improvement of center bit blade piece fixing ability)
A screw hole 313 is formed in the central cutting piece base 31 of the drill bit 30. As shown in FIGS. 1 and 4, the screw hole 313 corresponds to the concave hole 44 of the center bit blade 40, and the center of the screw hole 313 is slightly raised, and the deviation altitude is about 0. 05 mm. Due to the degree of deviation e, the center bit blade 40 rises, and when the screw 47 is stopped by the center bit blade 40, the screw 47 that has risen pushes up the concave hole 44 and at the same time slightly pushes the center bit blade 40 slightly. Lift up to. Further, the center bit blade 40 is further firmly tightened and integrally connected to the inclined side 312 and the inclined surface 311 of the center bit base 31 without having to worry about the tightening of the screw 47. Ensure the strength of resistance cutting stress.

(About improvement of drill bit strength by installing support blades)
As shown in FIG. 6, a support blade 53 and a support blade 54 are installed at appropriate positions above the inner blade 51 and the outer blade 52. The cutting size of the support blade 53 and the support blade 54 is the same as that of the outer blade 52 (the diameter has already been cut). At the time of cutting, when the upper two support blades 53 and 54 are applied to the inner surface of the inner blade 51, the outer blade 52 and the center bit blade 40 against the cutting hole surface, the drill body is supported and the drill strength is greatly improved. . Therefore, the present invention can be applied to drill deep holes, and can be applied to both general cutting and deep hole cutting to increase the practicality and the utilization rate.

(Various changes in drill bit size)
The drill bit size in this embodiment is determined by the structure of the blade. Therefore, the inner cutter 51 and the outer cutter are determined by the size of the drill bit. A small drill bit may be provided only with the inner cutter 51, and a larger drill bit is provided with the inner cutter 51 and the outer cutter 52. Since the inner blade 51 and the outer blade 52 are provided on the center bit blade 40, they are combined according to the bit size. FIG. 7 shows an embodiment of a drill bit having a small cutting diameter, all of which fall within the scope of the present invention, and are applied to the embodiment.

FIG. 3 is a perspective view showing a structure of the disposable drill bit according to the embodiment of the present invention; FIG. 3 is a plan assembly view showing the structure of the disposable drill bit according to the embodiment of the present invention. FIG. 4 is a partial enlarged view of a central part of a drill bit having a disposable drill bit structure according to an embodiment of the present invention; FIG. 4 is an enlarged view of the center drill bit blade of the structure of the disposable drill bit according to the embodiment of the present invention. FIG. 3 is a side view showing the structure of the disposable drill bit according to the embodiment of the present invention. FIG. 4 is a view showing an embodiment in which a support blade is installed in the present invention. FIG. 3 is a view showing an embodiment of a drill bit having a small cutting diameter according to the present invention. It is a plane indication figure of the conventional single piece type disposable drill bit. It is a plane indication figure of the conventional type disposable drill bit of another type.

Explanation of reference numerals

  2 Extension blades, 10 single-piece disposable drill bits, 11 blades, 12 bit edges, 13 scrap holes, 20 drill bits, 21 center bits, 22 inner blades, 23 outer blades, 30 drill bits, 31 center blades Table, 32 blade storage table, 33 blade storage table, 40 center bit blade, 41 center bit, 44 concave hole, 45 inclined side, 46 slope, 47 screw, 51 inner blade, 52 outer blade, 53 support blade, 54 Supporting blade, 311 Pigtail tank, 312 Inclined side, 313 Screw hole, 411 Cutting blade, 412 Cutting blade

Claims (3)

The center blade piece is installed at the center position of the end of the drill bit, and the center bit piece is fixed there, and the corresponding blade storage tables are installed on both sides of the center bit piece, and the inner and outer blades are fixed there. The structure of a disposable drill
The structure of a disposable drill, wherein the center bit cutting piece is formed by an extended cutting piece integrally formed on one side of the center bit.   The center bit blade piece has an inclined side on the uppermost one side near the center bit, the other side is parallel to the central axis, and a dovetail-shaped slope is formed, and one side of the center bit piece base of the drill bit is an inclined dovetail tank. 2. The structure of the disposable drill according to claim 1, wherein the other side is an inclined side and corresponds to the center bit side. The center blade piece base is provided with a screw hole, the screw hole corresponds to the concave hole of the center bit piece, and the center position of the screw hole is shifted slightly upward. 2. The structure of the disposable drill according to 1.

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