JPH0512023U - Drilling tool and its mounting structure - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a drilling tool capable of preventing plastic deformation of a connecting member and mounting a drilling tool having various diameters, and a mounting structure thereof. A recess (22) having a circular cross section whose center coincides with the axis is provided on the rear end surface of the tool body (20).
An oil hole (21) was opened on the bottom surface of 2). In order to connect this drilling tool, the connecting member (23) is provided with a convex portion (24) pressed against the wall of the concave portion (22), and an oil supply hole is provided at the tip end surface of the convex portion (24). (25) was opened.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mounting structure for detachably mounting a drilling tool such as a drill on a spindle such as a drilling machine, and an improvement of the drilling tool mounted by the mounting structure.

[0002]

[Prior Art]

 Conventionally, as a mounting structure as described above, a structure shown in FIG. 4 is known. In the mounting structure shown in this figure, a holder 2 is incorporated inside a spindle 1, and a collet chuck (grasping part) 4 having a drill 3 inserted in a central hollow portion is inserted into the tip of the holder 2. Is configured. In such a structure, the nut 5 of the collet chuck 4 is screwed onto the outer periphery of the tip of the holder 2 to push the collet 6 into the holder 2, thereby reducing the inner diameter of the collet 6 and tightening the drill. It is supposed to be fixed.

Here, an oil hole 7 is formed inside the drill 3 along the rotation center of the drill 3, and the oil hole 7 is branched into two branches at the tip of the drill 3 to make a tip. There is an opening on the flank. On the other hand, a preset driver 8 connected to the rear end of the drill 2 is inserted in the holder 2 at the back. A concave portion 9 is formed on the front 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, whereby the concave portion 9 is formed inside the preset driver 8. The oil supply hole 11 and the oil hole 7 of the drill 3 are connected to each other.

[0004]

[Problems to be solved by the device]

 By the way, in the drill 3 mounted by the mounting structure described above, the oil hole 7 is located on the center of rotation on the rear end side, but in recent years, as shown in FIG. 5, it has a spiral shape along the chip discharge recess 12. The drill 14 in which the oil hole 13 is formed is being used frequently. Then, for use in the mounting structure as described above, a tapered concave portion 16 is formed on the front end surface of the preset driver 15 so as to widen toward the front end side, and the taper surface of the concave portion 16 is formed. By pressing the rear edge portion of the drill 14, the oil hole 13 and the oil supply hole 11 are liquid-tightly connected. However, in such an attachment structure, the force that tries to spread the recess 16 with the drill 13 mounted always acts, so that the wall portion forming the recess 16 is likely to be plastically deformed. For this reason, it is necessary to set the wall thickness of the recess 16 to a predetermined value or more, but then there was a problem that only a small diameter drill could be mounted.

[0005]

[The purpose of the device]

 The present invention has been made to solve the above problems, and it is possible to prevent plastic deformation of the preset driver and, of course, a drilling tool and a drilling tool capable of mounting a large diameter drill. The purpose is to provide the mounting structure.

[0006]

[Means for Solving the Problems]

 The drilling tool of the present invention is provided with a recess having a circular cross section whose center coincides with the axis on the rear end surface of the tool body, and an oil hole is opened in the bottom surface of this recess. Further, in the mounting structure for a drilling tool of the present invention, the connecting member is provided with a convex portion to be pressed against the wall portion of the concave portion so that the drilling tool can be connected, and the tip surface of the convex portion is provided. The oil supply hole is opened.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 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 the other components shown in FIG. 4 are omitted. The reference numeral 20 indicates the rear end of the drill (tool body). Inside the drill 20, a spiral oil hole 21 is formed along the axis. A recess 22 is formed at the center of the rear end surface of the drill 20. As shown in FIG. 3, the concave portion 22 has a circular cross section and has a cylindrical side wall portion 22a. Further, a chamfer 22b is formed at the edge of the recess, and an oil hole 21 is opened at the bottom of the chamfer 22b. The drill 20 configured in this way is connected to a preset driver (connection member) 23.

A protrusion 24 is formed at the tip of the preset driver 23, and the tip of the protrusion 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 pressed against the chamfer 22b of the concave portion 22 so that the oil supply hole 25 and the oil hole 21 are liquid-tightly connected.

In the drill mounting structure configured as described above, since the recess 22 is generally formed in the drill 20 made of a high-rigidity material such as cemented carbide or high-speed steel, presetting is performed. It is less likely to be plastically deformed as compared with the case where a recess is formed in the driver 23. Further, not only a large-diameter drill can be mounted, but any small-diameter drill can be mounted by making the tip shape of the preset driver 23 sharper than that of the embodiment.

Although the concave portion 22 is formed in a cylindrical shape in the above-mentioned embodiment, it may be tapered so as to be fitted into the convex portion 24 by taper. Further, the convex portion 24 may be formed in a cylindrical shape. Furthermore, although the above-mentioned embodiment applies the present invention to a drill, it is needless to say that it can be applied to other drilling tools such as an end mill and a reamer.

[Effect of the device]

 As described above, in the drilling tool and its mounting structure of the present invention, the rear end face of the tool body is provided with a recess having a circular cross section whose center coincides with the axis line, and an oil hole is opened at the bottom of this recess. Also, in order to connect such a drilling tool, the connecting member is provided with a convex portion that is pressed against the wall portion of the concave portion, and an oil supply hole is opened at the tip end surface of this convex portion. Therefore, compared to the case where the recess is formed in the connecting member, the plastic deformation is less likely to occur, and the effect that the drilling tool with various diameters can be mounted can be obtained.

[Brief description of drawings]

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

FIG. 2 is a view on arrow II in FIG.

FIG. 3 is a view on arrow III in FIG.

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

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

[Explanation of symbols]

 20 Drill (Tool Body) 21 Oil Hole 22 Recess (Concave) 23 Preset Driver (Connecting Member) 24 Convex 25 Oil Supply Hole

Claims (2)

[Scope of utility model registration request] 1. A drilling tool in which an oil hole is provided inside a tool body that is rotated around an axis, the oil hole forming a spiral shape along the axis and opening at a rear end surface and a tip flank of the tool body, A drilling tool, characterized in that a recess having a circular cross section whose center coincides with the axis is provided on the rear end surface of the tool body, and the oil hole is opened on the bottom surface of the 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 surface and a tip flank, and the drilling tool is used for rotating a spindle. Mounting structure for a drilling tool, comprising a gripping portion that is detachably tightened and fixed on the 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 on the rear end surface of the tool body, the oil hole is opened in the bottom surface of the concave portion, and the connecting member is further provided with a convex portion that is pressed against the wall portion of the concave portion. A structure for mounting a drilling tool, characterized in that the oil supply hole is opened at the front end surface of the portion.