JP2003326411A - Drill for shape steel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drill for a shape steel to protect a holder and prevent breakage of the holder even when cemented carbide tip is broken. <P>SOLUTION: A holder 3 rotatable around an axis is situated. A base metal 11 with which a cemented carbide tip 7 is joined by a joining means 9 is removably fixed. The joining means is blazed, the tip part of the holder 3 and the center of the rear end part of the base metal 11 are intercoupled by coupling means 23 and 25 so that torque and concentricity are ensured. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaped steel drill for drilling a workpiece using a cemented carbide tip provided at the tip of a holder rotated about an axis.

[0002]

2. Description of the Related Art In a conventional built-in type throw-away drill, for example, a cemented carbide tip is directly attached to a tip of a holder rotatable about an axis by using screws.

[0003]

By the way, in the above-mentioned conventional, for example, built-in type throw-away drill, unlike the HSS drill, the cutting force does not increase so much even near the life limit. Have difficulty. Therefore, it cannot be detected until the carbide tip of the cutting edge is damaged, and at this time, the holder is often damaged.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a shaped steel drill which protects the holder and prevents the holder from being damaged even if the carbide tip is damaged. To do.

[0005]

In order to achieve the above object, a drill for shaped steel of the present invention according to claim 1 is provided with a holder rotatable about an axis, and a carbide tip is provided at a tip portion of the holder. The base metal joined by the joining means is detachably provided.

Therefore, since the cemented carbide tip is joined to the base metal by the joining means, the cemented carbide tip can be made small and the cost can be reduced. Further, since the base metal having better workability than the cemented carbide tip is used, it is easy to join the holder. Further, even if the cutting edge, which is a cemented carbide tip, is damaged, the cemented carbide tip is fixed to the holder via the base metal, so that the holder is also prevented from being damaged. If the cutting edge of the cemented carbide tip becomes worn, the cemented carbide tip can be re-polished like a cemented carbide brazed drill. Since the base metal in which the cemented carbide tip is joined by the joining means is detachably provided at the tip of the holder, the length of the holder can be freely changed when the drill length is changed.

According to a second aspect of the present invention, there is provided a shaped steel drill according to the first aspect, wherein the joining means is brazing.

Therefore, since the joining means is brazing, the cemented carbide tip can be easily and easily joined to the base metal.

According to a third aspect of the present invention, there is provided a shaped steel drill according to the first or second aspect, wherein the center of the tip of the holder and the center of the rear end of the base metal are torqued. , Are connected by a connecting means so as to ensure concentricity.

Therefore, since the center of the front end of the holder and the center of the rear end of the base metal are connected by the connecting means so as to ensure torque and concentricity, the holder and the base metal are connected to each other. The core is guaranteed and the torque is accurately and reliably transmitted from the holder to the carbide tip through the base metal.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings.

With reference to FIGS. 1 and 2, a shaped steel drill 1 is made of a hard material such as steel or cemented carbide, and is a holder 3 rotatable about an axis O as indicated by an arrow.
Is provided. A chip discharge groove 5 is formed on the outer periphery of the tip portion of the holder 3. Also, carbide tip 7
Is a base metal 11 by welding (brazing) 9 as a joining means.
Is joined to. On the outer circumference of the base metal 11, a chip discharge groove 13 which is the same as the chip discharge groove 5 formed on the outer circumference of the tip portion of the holder 3 is formed.

With the cemented carbide tip 7 and the base metal 11 joined together, the carbide tip 7 and the base metal 11 have a plurality of holes 15 and 17 in the vertical direction in FIG. The holes 19 are formed at the same positions. Then, for example, the bolt 21 as the attaching / detaching means is attached to the carbide tip 7
The base metal 11 can be removably attached to the holder 3 with the bolt 21 as shown in FIG.

Therefore, since the cemented carbide tip 7 is joined to the base metal 11 by welding (brazing) 9, the cemented carbide tip 7 can be made small and the cost can be reduced. Further, since the base metal 11 having better workability than the cemented carbide tip 7 is used, the joining process with the holder 3 can be easily performed. Further, even if the cutting edge which is the cemented carbide tip 7 is damaged, since the cemented carbide tip 7 is provided on the holder 3 through the base metal 11, it is possible to prevent even the holder 3 from being damaged, When the cutting edge of the hard tip 7 is worn, the cemented carbide tip 7 can be re-polished. Since the joining means is welding (brazing) 9, the cemented carbide tip 7 can be joined to the base metal 11 easily and easily.

At the center of the tip of the holder 3, for example, a concave portion 23 is formed as a coupling means, and at the center of the rear end of the base metal 11, for example, a convex portion 25 is formed as a coupling means. As a result, the convex portion 25 fits into the concave portion 23 and is coupled so as to ensure torque and concentricity. Therefore, the concentricity between the holder 3 and the base metal 11 can be guaranteed, and the torque can be accurately and surely transmitted from the holder 3 to the carbide tip 7 via the base metal 11.

Further, the length L of the base metal 11 in the height direction is such a length that the holder 3 will not be damaged even if the cutting edge of the cemented carbide tip 7 is damaged, and is preferably about 10 to 20 mm, for example. .

3 (A) to 3 (D) show examples of various coupling means other than the coupling means. 3 (A) is a serration 27, FIG. 3 (B) is a key 29, FIG. 3 (C) is a pin 31 and FIG. 3 (D) is an abutment 33, so that the holder 3 and the base metal 1 are joined together. Is.

FIG. 4 shows another embodiment of the section steel drill 35 which replaces the section steel drills of FIGS. 1 and 2. 4, parts that are the same as the parts shown in FIGS. 1 and 2 are given the same reference numerals, and redundant description will be omitted.

In FIG. 4, a through hole 37 that penetrates in the vertical direction in FIG. 4 is formed in the shaft core portion of the holder 3, and the recess 23 is also penetrated. A hole 39 is formed in the base metal 11 at the same position as the through hole 37. Then, for example, the bolt 4 as the attaching / detaching means
1 can be inserted from the through hole 37 of the holder 3, and the base metal 11 can be detachably provided on the holder 3 with the bolt 41 as shown in FIG.

Therefore, also in this embodiment,
The same action and effect as those of the above-described example are exhibited.

FIG. 5 shows another embodiment of the structural steel drill 43 which replaces the structural steel drills of FIGS. 1 and 2. 5, parts that are the same as the parts shown in FIGS. 1 and 2 are given the same reference numerals, and redundant description will be omitted.

In FIG. 5, a plurality of through holes 45 are formed in the holder 3 so as to be inclined in the vertical direction, and the base metal 11 at the same position as the through holes 45 has inclined holes 47. Has been formed. Then, for example, a bolt 49 as an attaching / detaching means is inserted from the through hole 45 of the holder 3, and the base metal 11 can be detachably fixed to the holder 3 with the bolt 49 as shown in FIG.

Therefore, also in this embodiment,
The same action and effect as those of the above-described example are exhibited.

FIG. 6 shows another embodiment of the section steel drill 51 which replaces the section steel drills of FIGS. 1 and 2. 6, parts that are the same as the parts shown in FIGS. 1 and 2 are given the same reference numerals, and repeated explanations are omitted.

In FIG. 6, the recess 23 of the holder 3
A thick portion between the base metal 11 and the convex portion 25 of the base metal 11 is thick, and the convex portion 25 has a through hole 5 penetrating in the left-right direction in FIG.
3 is formed. A through hole 55 penetrating in the left-right direction in FIG. 6 is formed in the recess 23 at the same position as the through hole 53. Then, for example, a bolt 57 as an attaching / detaching means is inserted from the left of the through hole 55 of the concave portion 23 of the holder 3, and as shown in FIG.
Therefore, the base metal 11 can be detachably fixed to the holder 3. In FIG. 6, the end surface 11 of the base metal 11
It is thrust at A.

Therefore, also in this embodiment,
The same action and effect as those of the above-described example are exhibited.

The present invention is not limited to the above-described embodiment, but can be implemented in other modes by making appropriate changes.

[0028]

As can be understood from the above description of the embodiments of the invention, according to the invention of claim 1, the cemented carbide tip is joined to the base metal by the joining means. The chip can be made smaller and the cost can be reduced. Further, since the base metal having better workability than the cemented carbide tip is used, the joining process with the holder can be easily performed. Furthermore, even if the cutting edge that is a carbide tip is damaged, the carbide tip is provided on the holder through the base metal,
It is possible to prevent even the holder from being damaged, and it is possible to re-polish the cemented carbide tip when the cutting edge of the cemented carbide tip wears. Since the base metal to which the cemented carbide tip is joined by the joining means is detachably provided at the tip of the holder, the length of the holder can be freely changed.

According to the second aspect of the present invention, since the joining means is brazing, the cemented carbide tip can be easily and easily joined to the base metal.

According to the third aspect of the present invention, the center of the tip of the holder and the center of the rear of the base are torque,
Since they are joined by the joining means to guarantee the concentricity, it is possible to guarantee the concentricity between the holder and the base metal, and at the same time, accurately and reliably transmit the torque from the holder to the carbide tip through the base metal. You can

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a shaped steel drill according to the present invention.

2 is a perspective view of the shaped steel drill in FIG. 1. FIG.

3A to 3D are views showing various examples of a coupling means.

FIG. 4 is a vertical cross-sectional view of another shaped steel drill of the present invention.

FIG. 5 is a vertical cross-sectional view of another shaped steel drill of the present invention.

FIG. 6 is a vertical cross-sectional view of still another shape steel drill of the present invention.

[Explanation of symbols]

1, 35, 43, 51 Shaped steel drills 3 holder 5 Chip discharge groove 7 Carbide chip 9 Welding (brazing) (joining means) 11 money 13 Chip discharge groove 15, 17, 19 holes 21 bolts 23 recess (coupling means) 25 Convex part (coupling means) 27 Serration 29 keys 31 pin 33 Butt 41, 49, 57 bolts

Claims (3)

[Claims] 1. A holder rotatable about an axis is provided,
A drill for shaped steel, characterized in that a base metal in which a cemented carbide tip is joined by a joining means is detachably provided at the tip of this holder. 2. The shaped steel drill according to claim 1, wherein the joining means is brazing. 3. The center of the front end portion of the holder and the center of the rear end portion of the base metal are connected by a connecting means to ensure torque and concentricity. Drill for shaped steel described.