JP2000107921A - Countersinking cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cope with the pilot-cum-shank parts by a small number of cutter bodies without causing a problem even when many different types of pilot-cum- shank parts are used. SOLUTION: A connecting part 2a of a pilot-cum-shank part 2 is inserted into a connecting hole 1b of a cutter body 1 from the cutting edge 1a side, and a hexagon socket set screw 3 is screwed into a set screw 1c formed in the cutter body 1 to lock-join the cutter body 1 to the pilot-cum-shank part. With the inverted countersinking cutter provided with a connecting part of this structure, the cutting edge 1a of the cutter body 1 can be provided near to the center, and the pilot-shank parts with the diameter of different, small and large size, which are to be inserted into and connected to the cutter body 1, can be coped with by one type of cutter body 1, and thus the number of the cutter bodies 1 can be minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a countersinking cutter for chamfering a hole formed in a work material, and more particularly to a countersinking cutter for chamfering a surface located in a narrow portion.

[0002]

2. Description of the Related Art A processing cutter for performing dishing on an edge of a cylindrical hole formed in a work material having a predetermined thickness and penetrating in a thickness direction is described in, for example, Japanese Patent Application Laid-Open No. 6-31518. . In this dishing cutter, a pilot body is formed at the tip of the blade side on a cutter body having a blade arranged in a conical shape at a predetermined angle with respect to the axis of the cylindrical hole, and a joint is formed on the opposite side of the blade. A part is formed. Then, an electric tool or the like is attached to the joint, and the cutter body is driven to rotate.

On the other hand, when the side on which the work material is to be dished is narrow, and a power tool or the like cannot be mounted from the opposite side of the blade in the cutter body, the blade of the cutter body is turned into a shank portion. A reverse dishing process is performed using a cutter facing the side. In this reverse dishing process, the cutter body with the joint formed on the same side as the blade is placed in the narrow part, and the shank with the joint formed at the tip from the opposite side of the work material is inserted into the cutter. It is connected to the main body, and a power tool etc. is connected to the base end side of this shank part to rotate the cutter body, and at this time, the shank part also serves as a pilot for fixing the shaft hole so that the cutter does not touch. ing.

[0004] As a conventional connection structure of a reverse dish-catching cutter, a connecting portion formed of a cylindrical hole is formed at the center of the cutter body, and the tip of a pilot / shank portion formed of a cylindrical shaft is inserted into the cylindrical hole and stopped. The structure was fixed with screws.

[0005]

However, in the case of a conventional reverse dish-catching cutter, it is necessary to provide a cutter body having a coupling portion formed of a cylindrical hole corresponding to various shaft diameters of the shank portion. As the number of types of shank parts increases, there is a problem that the number of types of cutter bodies connected to the shank parts also increases.

On the other hand, as shown in FIGS. 5A and 5B, a connecting portion 2 having a different shaft diameter is provided at the tip of a shank portion 20.
It is conceivable to form Oa and connect various types of shank portions 20 to one cutter body 10. However, according to this, in the case of FIG. 5A where the diameter a of the shank portion 20 is larger than the diameter A of the coupling portion, a large amount of rotational force is applied because dishing is performed outside the blade 10a of the cutter body 10. There is a problem in strength as needed. Further, in the case of FIG. 5B where the diameter a of the shank portion 20 is smaller than the diameter A of the coupling portion, there is a problem that the blade 10a cannot be used because it does not reach the inside.

The present invention has been proposed in order to cope with the above-mentioned situation, and has no problem in use, and can cope with a large number of types of shank portions with a small number of cutter bodies. It is an object to provide a possible dishing cutter.

[0008]

SUMMARY OF THE INVENTION To achieve the above object, a dish cutter according to the present invention comprises, firstly, a shank portion and an end face of a hole formed in a work material provided at a tip of the shank portion. A shank portion and a cutter body having a substantially frusto-conical cutter body for cutting the shank portion into a dish surface, and dividing the shank portion and the cutter body so that the center of the shaft coincides with the tip of the shank portion, and the diameter of the shank portion. A smaller cross-shaped shaft is formed, and a cross-shaped hole for fitting the cross-shaped shaft is provided in the cutter body so that the center of the shaft is aligned, and a substantially cutout having a tip diameter smaller than the diameter of the shank portion is provided. The frusto-conical cutter body is directed toward the shank portion, and the cross-shaped shaft of the shank portion is fitted and fixed to the cross-shaped hole of the cutter body.

Secondly, in addition to the above features, the blade of the cutter body is orthogonally arranged so as not to overlap with the cross-shaped hole.

According to the above configuration, even when the cutter body and the shaft are changed, the cross-shaped shaft and the hole can be configured to have the same size. Therefore, when changing the cutter body or when changing the shaft, Each can be changed independently, and even in a narrow portion, a cutter can be easily set in a chamfering hole and chamfering can be performed.

Further, since the blade of the cutter body is arranged orthogonally so as not to overlap with the cross-shaped hole, the blade of the cutter body can be provided up to the vicinity of the center, and the pilot and shank portion connected to the cutter body can be provided. From small to large diameters can be combined.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view of a cutter main body according to a connection structure of an inverted dish-catching cutter according to an embodiment of the present invention.
FIG. 1A is a front view, and FIG. 1B is a plan view. The cutter body 1 has four blades 1 each having a conical inclined blade surface.
a are orthogonally arranged. Then, a cross-shaped coupling hole 1b is disposed at a position where the center axis of the cutter body 1 and the center of the cross coincide with each other and are shifted by 45 ° with respect to the blade 1a that is arranged orthogonally. This coupling hole 1b is formed penetrating the cutter body 1 in the vertical direction. Also, the width L of the coupling hole 1b
Is a width that can be combined with the maximum diameter of the selected pilot / shank portion. Further, a set screw hole 1c is formed so as to reach the coupling hole 1b from the outer periphery of the cutter body 1. By forming the cutter body 1 in this way,
The blade 1a for performing reverse dishing can be arranged from the outer periphery of the cutter body 1 to the vicinity of the center.

FIGS. 2A and 2B are explanatory views of a pilot and shank portion relating to the connection structure of the inverted dish-catching cutter according to one embodiment of the present invention. FIG. 2A is a front view, and FIG. ,
FIG. 3C is a sectional view taken along the line AA. The pilot / shank portion 2 has a coupling portion 2a formed near the tip thereof. The connecting portion 2a is a shaft formed in a cross shape, as shown in the AA cross-sectional view of FIG.

FIG. 3 is an explanatory view showing a state in which the cutter body and the pilot and shank portion are connected to each other in the connection structure of the inverted dish-catching cutter according to one embodiment of the present invention. FIG. FIG. 1B is a plan view. The coupling portion 2a of the pilot / shank portion 2 is inserted into the coupling hole 1b of the cutter body 1 from the blade 1a side, and a set screw 3 with a hexagonal hole is screwed into a set screw hole 1c formed in the cutter body 1. The cutter body 1 and the pilot / shank portion 2 are fixedly joined.

[0016] In the inverted dish-equipped cutter provided with the coupling portion having such a structure, the blade 1a of the cutter main body 1 can be provided to the vicinity of the center, and the diameter of the pilot / shank portion 2 inserted into and coupled to the cutter main body 1 is provided. Since the diameter of the tip of the cutter body is smaller than the diameter of the shank portion and the diameter of the rear end of the cutter body is larger than the countersunk hole, it is possible to cope with one type of cutter body 1 from small to large. In addition, the number of the cutter bodies 1 can be reduced to a minimum.

A method of using the reverse dish-cutter according to the above embodiment will be described with reference to FIG. A narrow portion is formed above the work material 4, and a drill cannot be coupled to the cutter body 1 from above the work material 4. In such a situation, first, the cutter unit main body 1 with the set screw loosened is arranged in the narrow portion above the work material 4. Next, the front end of the pilot / shank portion 2 is inserted into the pilot hole 4a formed in the work material 4 from below the work material 4 so that the joint portion of the pilot / shank portion 2 faces the narrow portion. Then, the connecting portion of the pilot / shank portion 2 is inserted into the connecting hole of the cutter portion main body 1, and the set screw 3 is tightened to fix the cutter main body 1 and the pilot / shank portion 2. Thereafter, the drill 5 is attached to the base end of the pilot and shank portion 2, and the pilot hole 4 a of the work material 4 is subjected to reverse dishing while the drill 5 is being pulled.

[0018]

According to the dishing cutter of the present invention, a cross-shaped shaft is formed at the tip of the shank, a cross-shaped coupling hole is formed in the cutter body, and the shank is connected to the cutter body. Even if the number of types of shank portions increases, it is possible to cope with a small number of types of cutter bodies.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a cutter main body according to a connection structure of an inverted dish-catching cutter according to one embodiment of the present invention.

FIG. 2 is an explanatory view of a pilot and shank portion according to a connection structure of the inverted dish-catching cutter according to one embodiment of the present invention.

FIG. 3 is an explanatory view showing a state in which the cutter body and the pilot / shank portion are connected to each other in the connection structure of the inverted dish-catching cutter according to one embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a method of using the inverted dish-catching cutter according to one embodiment of the present invention.

FIG. 5 is an explanatory view showing a problem of a conventional inverted dish removing cutter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cutter body 1a Blade 1b Coupling hole 1c Set screw hole 2 Pilot and shank part 2a Coupling part 3 Set screw

Claims (2)

[Claims] 1. A dish-cutting cutter comprising: a shank portion; and a substantially frusto-conical cutter body provided at a tip of the shank portion and cutting an end face of a hole formed in a work material into a dish surface. Divide the shank portion and the cutter body, form a cross-shaped shaft smaller than the diameter of the shank portion by aligning the shaft center with the tip of the shank portion, and form a cross-shaped hole for fitting the cross-shaped shaft. A substantially frusto-conical cutter body having a tip diameter smaller than the diameter of the shank portion is provided on the cutter body so that the axial center thereof is aligned with the shank portion. A dish cutter, wherein the cross-shaped shaft is fitted and fixed. 2. The dish cutter according to claim 1, wherein the blades of the cutter body are arranged orthogonally so as not to overlap the cross-shaped holes.