JP2541158Y2 - Drilling tool and its mounting structure - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for detachably mounting a drilling tool such as a drill on a spindle of a drilling machine or the like, and to an improvement of a drilling tool mounted by the mounting structure. is there.

[0002]

2. Description of the Related Art Conventionally, a structure shown in FIG. 4 is known as the above-mentioned mounting structure. The mounting structure shown in this figure is one in which a holder 2 is incorporated in a spindle 1, and a collet chuck (holding portion) 4 having a drill 3 inserted through a central hollow portion is inserted into the tip of the holder 2. It is configured. In such a structure, the nut 5 of the collet chuck 4 is screwed into the outer periphery of the distal end of the holder 2 to push the collet 6 deep into the holder 2, thereby reducing the inner diameter of the collet 6 and tightening the drill. It is designed to be fixed.

[0003] The inside of the drill 3 is formed along the center of rotation of the drill 3 with an oil hole 7 opened at its rear end face. The oil hole 7 branches into two branches at the tip of the drill 3 and escapes at the tip. Open to the surface. On the other hand, a preset driver 8 connected to the rear end of the drill 2 is inserted in the back of the holder 2. A concave portion 9 is formed on the tip end surface of the preset driver 8, while a convex portion 10 that fits into the concave portion 9 is formed on the rear end portion of the drill 3, thereby forming the inside of the preset driver 8. The supplied oil hole 11 and the oil hole 7 of the drill 3 are connected.

[0004]

By the way, in the drill 3 mounted by the above-described mounting structure, the oil hole 7 is located on the center of rotation at the rear end side, but recently, as shown in FIG. Oil hole 13 spiraling along recess 12
The drill 14 in which is formed is being frequently used. And
For use in the above-described mounting structure, a tapered concave portion 16 that expands toward the distal end is formed on the distal end surface of the preset driver 15, and the rear end of the drill 14 is formed on the tapered surface of the concave portion 16. By pressing the edge portion, the oil hole 13 and the oil supply hole 11 are connected in a liquid-tight manner.
However, in such a mounting structure, the drill 13
Since the force for pushing and expanding the concave portion 16 always acts in the state in which is mounted, the wall constituting the concave portion 16 is easily plastically deformed. For this reason, it is necessary to set the thickness of the recess 16 to a predetermined value or more. However, there is a problem that only a small diameter drill can be mounted.

[0005]

The purpose of the present invention is to solve the above-mentioned problems, and it is possible to prevent the plastic deformation of the preset driver and to mount a large-diameter drill. It is an object of the present invention to provide a drilling tool and a mounting structure thereof.

[0006]

In the drilling tool of the present invention, a recess having a circular cross section whose center coincides with the axis is provided on the rear end face of the tool body, and the wall of the recess is provided on the spindle.
Forming a chamfer to which the connected connecting members
An oil hole is opened at the bottom of the recess. In addition, the mounting structure of the drilling tool of the present invention is provided with a convex portion pressed against the wall portion of the concave portion in the connecting member so that the drilling tool can be connected, and a distal end surface of the convex portion is provided on the connecting member. This is one in which an oil supply hole is opened.

[0007]

1 to 3 show an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a sectional view showing a mounting structure of the embodiment. In this figure, only the drill and the preset driver are shown, and other components shown in FIG. 4 are omitted. In the drawing, reference numeral 20 indicates a rear end portion of the drill (tool main body). Inside the drill 20, an oil hole 21 which forms a spiral along the axis is formed. Drill 2
A recess 22 is formed at the center of the rear end face of the zero. As shown in FIG. 3, the concave portion 22 has a circular cross-section and has a cylindrical side wall 22a.
A chamfer (tapered surface) 22b is formed along the edge.
Have been. Further, an oil hole 21 is opened on the bottom surface. And the drill 20 configured as described above
Are connected to a preset driver (connection member) 23.

A projection 24 is formed at the tip of the preset driver 23, and the tip of the projection 24 is tapered. An oil supply hole 25 is formed inside the preset driver 23 including the convex portion 24. The tapered surface of the convex portion 24 is the chamfer 22b of the concave portion 22.
Is pressed into contact with the surface in the circumferential direction, so that the oil supply hole 2
5 and the oil hole 21 are connected in a liquid-tight manner.

In the drill mounting structure configured as described above, the recess 22 is generally formed in the drill 20 made of a high-rigidity material such as cemented carbide or high-speed steel. It is less likely to be plastically deformed than when a recess is formed in the driver 23. In addition to being able to mount a large-diameter drill, it is possible to mount any small-diameter drill by making the tip shape of the preset driver 23 sharper than that of the embodiment.

In the above embodiment, the concave portion 22 is formed in a cylindrical shape.
And a chamfer 22b is formed along the side wall 22a.
Although all the walls of the recess 22 are tapered,
The protrusion 24 may be taperedly fitted. Also,
The protrusion 24 may be formed in a columnar shape. Further, in the above embodiment, the present invention is applied to a drill, but it is needless to say that the present invention can be applied to other drilling tools such as an end mill and a reamer.

[Effect of the invention] As explained above, the drilling tool of the present invention
In the mounting structure, a recess circular cross section centered on the rear end face of the tool body coincides axis doers provided a cylindrical recess
A tapered surface is formed on the side wall portion of the recess and an oil hole is opened in the bottom surface of the recess, and the convex portion is in close contact with the tapered surface of the recess so that such a drilling tool can be connected.
Is provided on the connecting member, and an oil supply hole is opened at the tip end surface of the convex portion . Therefore, plastic deformation is less than in the case where a concave portion is formed in the connecting member, and holes of various diameters are formed. The effect that a tool can be attached can be obtained. Also, since the fluid tightness between the oil supply hole and the oil hole is increased, the cutting oil
Leakage can be prevented.

[Brief description of the drawings]

FIG. 1 is a partially broken side sectional view showing a connection structure of a drill according to an embodiment of the present invention.

FIG. 2 is a view in the direction of arrow II in FIG. 1;

FIG. 3 is a view as seen in the direction of arrow III in FIG. 1;

FIG. 4 is a side sectional view showing a conventional mounting structure.

FIG. 5 is a partially broken side view showing another example of the conventional mounting structure.

[Explanation of symbols]

 Reference Signs List 20 drill (tool body) 21 oil hole 22 concave part (recess part) 23 preset driver (connection member) 24 convex part 25 oil supply hole

Claims (2)

(57) [Scope of request for utility model registration] 1. A drilling tool provided with an oil hole formed inside a tool body that is rotated around an axis, spirally along the axis, and opened at a rear end face and a tip flank of the tool body. A concave portion having a circular cross section whose center coincides with the axis is provided on a rear end surface of the tool body, and a wall portion of the concave portion is provided.
To which a connecting member provided on the spindle abuts.
A drilling tool characterized by forming an oil hole on the bottom surface of a concave portion while forming a recess. 2. A drilling tool in which a spiral oil hole is provided along a rotation center line and the oil hole is opened in a rear end face and a tip flank, and the drilling tool is used to rotate the spindle. A mounting structure for a drilling tool, comprising: a gripping portion which is removably fastened and fixed on a center; and a connecting member to which a rear end of the drilling tool is connected and which is provided with an oil supply hole communicating with the oil hole. In the above, a concave portion is provided in a rear end surface of the tool body, the oil hole is opened in a bottom surface of the concave portion, and further, a convex portion which is pressed against a wall portion of the concave portion is provided in the connection member. A mounting structure for a drilling tool, characterized in that the oil supply hole is opened at a tip end surface of the portion.