JPH08118134A - Centering cutting tool - Google Patents

Abstract

PURPOSE: To obtain desirable cutting quality and high cutting edge strength so as to dissolve the cause of chattering vibration, and improve the fitting stability of a throw away tip so as to improve the accuracy of the cut face. CONSTITUTION: A tip body 4 of plane rhombic shape formed of hard metal with the pointed tips 2 corresponding to a centering machining angle and with a locking hole 3 piercingly provided at the plane center is provided with cutting edges 5 respectively formed at a pair of opposed faces of the plane. A throw away tip A with tip part clearance angles and tip breakers 6 formed along the cutting edges 5 can be removably fixed to the fitting seat 10 of a tip fitting shank B by a fixing eccentric pin C, in the state of the pointed tips 2 of the tip body 4 being displaced onto the cutting edge 5 side by 0.2mm in relation to the rotating centerline 13 of a shank part 8 at the time of fitting the tip A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centering cutting tool using a throw-away tip used mainly for centering and, if necessary, for chamfering and V-groove processing.

[0002]

2. Description of the Related Art Conventional centering processing is carried out by means of using a tip in which a cutting blade for a slower way type end mill is formed at a predetermined angle after positioning with a center drill.

[0003]

However, in the above-mentioned conventional centering process, the cutting tool must be replaced in the working process, the machining efficiency is extremely low, and the machining cost is high. Set the angle to the angle corresponding to the centering processing angle, and use a square or diamond-shaped throwaway tip made of cemented carbide with a locking hole in the center of the plane, and insert the tip of the tip into the center of rotation of the shank for mounting. A centering cutting tool that uses a throw-away tip that is fixed to the mounting seat formed on the mounting tip in line with the line by means of a detachable means using screws has been developed and is commercially available. Since the cutting state is so-called "push-cutting", the cutting edge is stuck in, causing chatter vibration, high precision machining cannot be expected, and it concentrates on the cutting edge. A large load is applied, durability deteriorates, leading to chipping of the cutting edge.Because the side surface is formed at an acute angle to the flat surface, adhesion to the side wall surface of the mounting seat is hindered. There was a problem with the attachment stability of the away tip, and there was a problem to be solved in that high precision of the cutting surface could not be obtained due to these problems.

The present invention is mainly used for centering, which has good sharpness and strong cutting edge strength, eliminates the cause of chattering vibration, improves the stability of the insert of the throw-away tip, and improves the cutting surface accuracy. The purpose is to provide a cutting tool for centering used for machining.

[0005]

A centering cutting tool according to the present invention, which is mainly used for centering, has a pair of facing angles as a point corresponding to the centering angle and a locking hole at the center of the plane. In a square or diamond-shaped chip body made of a penetrating cemented carbide member, a cutting blade is formed on one or both of a pair of opposing sides of a plane, and a chip breaker is provided along the cutting blade, and the tip portion is further provided. In the ridgeline where the side faces that form the cross section are formed, a throw-away tip with a sharp tip and a clearance angle is formed, and the tip of the shaft is formed into a cone shape corresponding to the tip of the tip The tip mounting shank has a mounting seat so that the tip of the tip body displaces 0.2 to 0.6 mm to the cutting blade side with respect to the axis of rotation of the shaft when the tip is mounted. In addition, the throw-away tip is fixed to the attachment seat by a replaceable fixing means, for example, an eccentric pin method.

[0006]

With the centering cutting tool of the present invention, the tip of the tip body is fixed by displacing it to the cutting edge side by 0.2 to 0.6 mm with respect to the center line of rotation of the shank for mounting the tip. Since it is so-called "pull-off", there is no plunging of the cutting edge, the cause of chattering vibration is eliminated, and the load on the cutting edge is reduced, and damage to the cutting edge is prevented, resulting in excellent durability. .

Further, since the side surface of the tip body is formed at a right angle to the plane, the attachment stability of the throw-away tip is improved, which also contributes to elimination of chatter vibration and prevention of damage to the cutting edge.

Further, according to a second aspect of the present invention, as a replaceable fixing means, a screw shaft portion having an eccentric shaft formed at a tip thereof is screwed into a mounting seat, and the eccentric shaft protruding from the mounting seat is attached to the chip body. An eccentric pin method is used to insert a locking hole penetrating through the insert and to fix and release the throw-away tip by rotating the screw shaft. It can be secured easily and accurately.

[0009]

FIG. 1 is an exploded front view of a cutting tool for centering according to the present invention, FIG. 2 is an exploded side view, and FIG. 3 is an enlarged front view of the tip of the cutting tool. It comprises a shank B for fixing and an eccentric pin C for fixing.

The throw-away tip A has a pair of facing angles which are the tips 2 corresponding to the centering processing angle, and a flat diamond-shaped tip body 4 made of a super hard member having a locking hole 3 penetrating at the center of the plane. The cutting edge 5 is formed on both of the pair of opposing sides, and a chip breaker 6 is provided along the cutting edge 5, and a sharp tip is formed as a pointed portion at the ridge line portion where the side surfaces forming the pointed portion 2 intersect. The tip clearance angle 7 is formed.

The tip mounting shank B has a tip portion of the shaft portion 8 formed in a conical shape corresponding to the tip of the tip body 4, and an elevation angle 9b larger than the elevation angle 9a of the inclined surface of the conical portion with respect to the horizontal plane. To form a mounting seat 10, and the mounting seat 10 is a seat surface 1 in which fixing screw holes 11 are provided at right angles.
2 and a position formed between the center of the tip 2 of the tip body 4 and the rotation center line 13 of the shaft portion 8 at the time of mounting the tip at a position allowing a movement amount D of 0.2 mm toward the cutting blade 5 side. It is composed of the side wall 14.

Further, the fixing eccentric pin C is similar to the conventional one.
An eccentric shaft 16 is formed at the tip of the screw shaft portion 15, and a hexagonal bar wrench hole 17 is formed in the rear end portion axial direction. The fixing screw hole 11 is screwed into and protrudes from the mounting seat 10. The eccentric shaft 16 is inserted into the locking hole 3 penetrating the tip body 4, and the throw-away tip A is fixed and released by rotating the screw shaft portion 15.

In the above embodiment, the displacement amount between the tip of the tip body 4 and the rotation center line 13 of the shaft portion 8 was set to 0.2 mm. However, the displacement amount is not limited to this, and the displacement may be made. The object of the present invention can be achieved in the range where the belly button formed by the above does not hinder the center hole, that is, 0.2 to 0.6 mm.

[0014]

According to the centering cutting tool of the present invention described above, the center of the tip of the tip body is displaced by a displacement of 0.2 to 0.6 mm with respect to the center line of rotation of the shank for tip mounting. Since it is displaced and fixed to the side, the cutting state becomes so-called "pull-off", the plunging of the cutting edge is eliminated, the cause of chatter vibration is eliminated, and the load burden on the cutting edge is reduced, and the cutting edge is lost. Can be prevented, and a highly accurate cutting surface can be formed and excellent in durability.

Further, since the side surface of the tip body is formed at right angles to the plane, the throw-away tip has good mounting stability, which also contributes to elimination of chatter vibrations and prevention of damage to the cutting edge.

Further, as a second aspect of the present invention, as the exchangeable fixing means, a screw shaft portion having an eccentric shaft formed at its tip is screwed in, and the eccentric shaft protruding from the mounting seat is provided through the chip body. By adopting an eccentric pin system that inserts into the lock hole and locks and releases the throw-away tip by rotating the screw shaft, it is easy to secure the deviation amount of the tip body tip with respect to the rotation center line of the tip mounting shank. Can be accurate.

[Brief description of drawings]

FIG. 1 is an exploded front view of a centering cutting tool according to the present invention.

FIG. 2 is an exploded side view of the centering cutting tool according to the present invention.

FIG. 3 is an enlarged front view of the tip portion of the cutting tool for centering according to the present invention.

[Explanation of symbols]

 A Throw-away tip B Tip mounting shank C Fixing eccentric pin D Displacement amount 2 Tip 3 Lock hole 4 Tip body 5 Cutting blade 6 Tip breaker 7 Tip clearance angle 8 Shaft portion 9a Elevation angle 9b Elevation angle 10 Mounting seat 11 For fixing Screw hole 12 Bearing surface 13 Rotation center line 14 Side wall for regulation 15 Screw shaft portion 16 Eccentric shaft 17 Hole for hex bar wrench

Claims (2)

[Claims] 1. A flat square or diamond-shaped chip body made of a superhard member having a pair of facing angles corresponding to a centering processing angle, and a locking hole formed through the center of the flat surface, and a pair of facing sides of the flat surface. While forming a cutting blade on one or both, provided a chip breaker along the cutting blade, further, at the ridge line portion where the side face forming the pointed portion intersects, a tip clearance angle is formed with a sharp tip as a pointed portion. The throw-away tip and the tip of the shaft portion are formed in a conical shape corresponding to the tip of the tip body, and the tip of the tip body is attached to the conical portion with respect to the rotation center line of the shaft when the tip is attached.
It is characterized by comprising a tip mounting shank having a mounting seat formed so as to be displaced by 2 to 0.6 mm toward the cutting blade, and the throw-away tip is fixed to the mounting seat by a replaceable fixing means. Ring cutting tool. 2. A replaceable fixing means, wherein a screw shaft portion having an eccentric shaft formed at its tip is screwed into a mounting seat, and the eccentric shaft protruding from the mounting seat is inserted into a locking hole penetrating the chip body. The centering cutting tool according to claim 1, which is an eccentric pin system in which the throw-away tip is fixed and detached by inserting and rotating the screw shaft portion.