JPH0653012U - High precision ball end mill - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to the improvement of the accuracy of the throw-away ball end mill, and in particular, the method of mounting and fixing the throw-away tip is improved to improve the accuracy and provide a highly efficient cutting tool. The purpose is to [Structure] The throw-away tip of the present invention has a disk shape on one side and a V shape on the other side, and by providing one or two pin holes, the accuracy at the time of mounting at the V shape part is increased and the arc shape is formed. Since the cutting blade is formed in one chip, more excellent processing accuracy can be obtained, and the rigidity can be increased by sandwiching the chip.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a high-precision ball end mill mainly used for finishing a ball end mill used for metal cutting.

[0002]

[Prior art]

 A conventional throw-away type ball end mill is composed of a throw-away tip, which corresponds to the cutting edge, and a main body that grips the tip, and is used by being fastened to the machine main body via a holder. The throw-away tip used here has a special shape so that the rotation trajectory is almost spherical. (As an example, actual Kaihei 1-170511) For those requiring precision, a solid ball end mill or a bladed ball end mill fixed by brazing or the like is used.

A tool that uses a special throw-away tip only fixes the center part of the tip, but in this case, the accuracy of the fixing screw is an important factor, and maintaining the screw accuracy is important. It was difficult and there was a drawback that the accuracy deteriorated during use.

[0004]

[Problems to be solved by the device]

 However, in throw-away ball end mills, it is difficult to obtain high precision because the cutting blade has little flexibility. The reason for this is to provide compatibility by throwing away, because even if each of these parts is highly accurate, variations will occur in the set state.

[0005]

[Means for solving the problem]

 Therefore, according to the present invention, a V-shaped slit extending in the axial direction of the holder body is provided at the tip of the holder body of the throw-away tool, and the slit is formed at the tip side open portion of the holder body. If a tip seat that holds a throw-away tip with a cutting blade is formed at the tip protruding from the tip seat, and the width of these tip seats is made between the hollow seat seats that are bisected by the slit. A ball end mill that presses in a full direction to sandwich the throw-away tip by the tip seat, and at the same time, is provided with a tightening member to be detachably fixed, while maintaining high rigidity, It is designed to enable the holder to reproduce high precision, especially the precision obtained by set polishing.

[0006]

[Action]

 In the present invention, first, a V-shaped slit extending in the axial direction of the holder main body is provided at the tip of the holder main body to position the chip and reduce accuracy variations due to the chip and the screw. The holder is now able to reproduce the high-precision state of set polishing.

In addition, the tip seat is pressed in a direction in which the width of the tip seat is narrowed between the tip seats of the hollow portion divided by the slit so that the throw-away tip is sandwiched by the tip seats. Due to the structure, the mounting strength is improved and the thickness of the holder is sufficient to increase the rigidity. Further, if the V-shaped portion is also provided with the tightening member, the positioning of the chip and the fixing of the chip can be performed separately, which makes the handling easier.

[0008]

【Example】

 Hereinafter, the present invention will be described in detail based on embodiments. FIG. 1 shows an example of a ball end mill according to the present invention, which has a shank diameter of φ32 and a blade diameter of φ32. It is tapered to make the blade length thicker. As shown in FIG. 3, the throw-away tip has a disk shape on one side and a V shape on the other side and has two pin holes.

In addition, the shape of the cutting edge on the center side has a curved cutting edge ridge from the central side to the outer peripheral side, and during cutting, the cutting edge continuously contacts the work material to prevent chatter and vibration. Is decreasing. Due to poor machinability in the vicinity of the center, an excessive load is applied, and in order to fix the chip and maintain sufficient strength, it is sandwiched by the chip seats 2 and 3. In addition, since the cutting edge on the central side and the cutting edge on the outer peripheral side are made with a single tip, set polishing can be performed during processing, and the accuracy during processing can be reproduced even after mounting. ˜2 μm) is obtained.

Further, one end of the tip seats 2 and 3 is the most stressed portion even in the base metal portion of the blade length portion, and this phenomenon is caused by stress concentration on the tip seat of the cutting edge and fatigue fracture at that portion. Or, excessive stress concentration tends to cause strength failure. Therefore, if the entire base metal portion of the chip seats 2 and 3 is subjected to surface modification treatment-hardening treatment such as peening and blast or modification treatment such as ion implantation in order to improve strength, the strength is further improved. Can be measured.

[0011]

[Effect of device]

 According to the present invention, a V-shaped slit is provided at the tip of the holder body of the throw-away tool to improve accuracy, and the tip seat that holds the throw-away tip increases the mounting strength, so high rigidity is maintained. At the same time, it is possible to maintain high precision, especially the precision of mounting the tip during processing, so variations due to mounting are reduced, and the precision of screws and the like is less affected, and high precision can be maintained.

[Brief description of drawings]

FIG. 1 is a front view of the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 shows a top view of a throw-away tip.

FIG. 4 shows a front view of FIG.

5 is a right side view of FIG. 3. FIG.

[Explanation of symbols]

 1 Holder 2 Tip seat 3 Tip seat 4 Throw-away tip 5 Set screw

Claims (2)

[Scope of utility model registration request] 1. A V-shaped slit extending in the axial direction of the holder main body is provided at the front end of the holder main body, and the slit is cut at the front end of the holder main body that is open at the front end side of the holder main body. A tip seat for holding a throw-away tip having a blade is formed, and the throw-away is performed by pressing the tip seats in the hollow portion divided by the slit in a direction in which the width of the tip seats is narrowed. A high-precision ball end mill characterized in that a tip is clamped by the tip seat and a fastening member is provided so as to be detachably fixed. 2. The high precision ball end mill according to claim 1, wherein the V-shaped portion is also provided with a fastening member and is detachably fixed.