JPH0722848B2 - Ball end mill - Google Patents

Description

TECHNICAL FIELD The present invention relates to a ball end mill having an improved tip.

[Conventional technology]

In a conventional ball end mill, as shown in FIG. 8, a cutting blade 23 is formed in a threaded shape at the tip of the spindle body 2,
The hole in the work was cut by rotating the main spindle 2. Q [Problem to be solved by the invention] However, in the conventional ball end mill of this type, during the cutting, Since the tip blade part 233 often contacts the work, it is likely to be partially worn,
As a result, there is a disadvantage that the life of the ball end mill must be shortened.

An object of the present invention is to eliminate such inconvenience.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, in the ball end mill according to the present invention, a pair of tip shaft portions are provided so as to project at the tip portion of the main shaft body, and a slit is formed between the pair of tip shaft portions. While inserting the cutting disc blade into the peripheral edge portion of the cutting disk blade is rotatably supported on the tip shaft portion in a state of slightly protruding from the tip edge of the tip shaft portion, Further, a through hole is formed in the axial direction of the main shaft body, and an interlocking shaft is fitted into the support hole, and the rotation of the interlocking shaft can be transmitted to the cutting disc blade by a vertical rotation transmitting means. is there.

A pair of bevel gears can be used as the vertical rotation transmission means.

[Operation of the invention]

Since the ball end mill according to the present invention is configured as described above, if the main shaft body is rotated about the shaft center while rotating the cutting disc blade, the peripheral edge portion of the cutting disc blade The work can be cut by the portion protruding from the tip shaft portion.

If a pair of bevel gears are used as the vertical rotation transmission means, it is easy to manufacture a ball end mill.

[Explanation of Examples]

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

In FIG. 1 and FIG. 2, E is a ball end mill, which is installed on the machining center 12 via a chuck 11.

Reference numeral 2 denotes a main shaft body of the ball end mill E, which has a cylindrical shape. The main shaft 2 is composed of a pair of components 21 and 2 having a semi-cylindrical shape.
It is composed by bonding two. Note that 23
Is a blade.

Next, in FIG. 3, reference numerals 31 and 32 are tip shaft portions, which are integrally formed with the constituent members 21 and 22, respectively. These tip shaft portions 31 and 32 are provided so as to project in the tip direction of the end mill E. S is a slit, and the pair of tip shaft portions 31, 32
Is formed between. Further, 4 is a disc blade for cutting (see FIG. 4), which is fitted in the slit S so that the tip shaft portions 31 and 32 can rotate via the support shaft 5. is set up. The peripheral edge portion 41 of the cutting rotary blade 4 partially projects from the tips of the tip shaft portions 31, 32. With this protruding peripheral edge portion 41, this end mill E
Cuts the work. The tip edges of the tip shaft portions 31, 32 are narrowed to match the peripheral edge portion 41 of the cutting disc blade 4 as shown in FIG.

Next, 61 is a driven bevel gear, which is used for the cutting disc blade 4
The driven bevel gear 61, which is integrally formed with the cutting disc blade 4, rotates together with the cutting disc blade 4.
Reference numeral 7 is a support hole, which is formed in the main shaft body 2 along the axial direction thereof. An interlocking shaft 71 is fitted in the support hole 7. Reference numeral 62 is a speech bevel gear, which is fixed to the lower end of the interlocking shaft 71. The behavioral bevel gear 62 meshes with the driven bevel gear 61. Therefore, when the interlocking shaft 71 rotates about the shaft center, the cutting disk blade 4 rotates via the pair of bevel gears (corresponding to the "vertical rotation transmitting means" of the present invention) 61 and 62. Reference numeral 8 is a rotary drive source, which is installed in the chuck 11 (see FIG. 2). The rotary drive source 8 may be a fluid motor or an electric motor. The rotary drive source 8 is for rotating the interlocking shaft 71, but any means such as a normal connecting means can be used even if the connection is a key connection.

In addition, as shown in FIG. 5, the disc blade 4 for cutting is made thick, and its cross section is formed in an arc shape according to the curved surface of the tip shaft portions 31, 32, and the peripheral edge thereof is formed in a knurled shape. You can also

In addition to the tooth profile shown in FIG. 4, the tooth profile of the cutting disk blade 4 may have the tooth profile shown in FIG. 6 or the tooth profile shown in FIG. The tooth tips of the tooth profile shown in FIG. 7 have concentric arcs. In order to use the ball end mill E configured as described above, the end mill E may be rotated while operating the rotary drive source 8. Rotation drive source 8
Is operated, the interlocking shaft 71 rotates and the pair of bevel gears 6
The cutting disc blade 4 rotates via 1, 62, and the portion of the cutting disc blade 4 protruding from the tip end shaft portions 31, 32 of the peripheral edge blade portion 41 cuts the work.

In the above embodiment, the pair of bevel gears 61 and 62 are used as the vertical rotation transmission means, but the vertical rotation transmission means of the present invention is not limited to this, and has the same function. Any means of is included.

〔The invention's effect〕

In the ball end mill according to the present invention, a pair of tip shaft portions are projected at the tip portion of the main shaft body, and a slit is formed between the pair of tip shaft portions, and a disc blade for cutting is inserted into the slit. In addition, the peripheral edge portion of the cutting disk blade is rotatably supported on the tip shaft portion in a state of slightly protruding from the tip edge of the tip shaft portion, and is supported in the axial direction of the spindle body. Since the hole is formed and the interlocking shaft is inserted into this through hole, and the rotation of this interlocking shaft can be transmitted to the cutting disc blade by the vertical rotation transmission means, the main shaft can be rotated while rotating the cutting disc blade. If the body is rotated about the axis, the work can be cut by the portion of the cutting disk blade protruding from the tip shaft portion of the peripheral edge blade portion.

Therefore, in the ball end mill of the present invention, since the peripheral edge portion of the cutting disc blade can be used equally over the entire peripheral edge, the cutting disc blade is less likely to wear, and as a result, the ball end mill The life is improved.

If a pair of bevel gears are used as the vertical rotation transmission means, it is easy to manufacture a ball end mill.

[Brief description of drawings]

The drawings show an embodiment of the ball end mill according to the present invention. Fig. 1 is a front view, Fig. 2 is a partial sectional side view, and Fig. 3 is an enlarged sectional view of a portion III in Fig. 2, Fig. 4 Is a front view of a disc blade for cutting, FIG. 5 is a view of another embodiment corresponding to FIG. 3, FIG. 6 is a view of another embodiment corresponding to FIG. 4, and FIG. FIG. 8 is a view of still another embodiment corresponding to the drawing, and FIG. 8 is a view of a conventional example corresponding to FIG. 2 ... Main shaft 31, 32 ... Tip shaft 4 ... Cutting disk blade 41 ... Peripheral blade 7 ... Support hole 71 ... Interlocking shaft 61 ... Driven bevel gear (vertical rotation transmission means) 62 ...... Driving bevel gear (vertical rotation transmission means) E …… Ball end mill S …… Slit

Claims (2)

[Claims] Claims: 1. A pair of tip shaft portions are provided so as to project from the tip portion of a main shaft body, a slit is formed between the pair of tip shaft portions, and a disc blade for cutting is fitted in the slit. The peripheral edge portion of the cutting disk blade is rotatably supported on the tip shaft portion while slightly protruding from the tip edge of the tip shaft portion, and a through hole is formed in the axial direction of the spindle body. A ball end mill, characterized in that it is formed and an interlocking shaft is fitted into the support hole, and the rotation of the interlocking shaft can be transmitted to the cutting disk blade by a vertical rotation transmission means. 2. The ball end mill according to claim 1, characterized in that the absolute vertical rotation transmission means is a pair of bevel gears.