JPH10286705A - Balance cut holder for boring cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balance cut holder for boring work in which a hole diameter range subject to processing is large, and in which strength and rigidity can be sufficiently large. SOLUTION: Two cutting blade holders 2, 3 extended in opposite directions to each other are installed on a tip of a holder main body 1 in axially perpendicular directions in the condition where they are combined with each other in axial directions. The tip of the holder main body 1 is provided with a recessed groove or protrusion 7 to radially guide the cutting blade holder 2 on the holder main body side, the cutting blade holder 2 is provided with a guide means 18 to guide the cutting blade holder 3 on the counter holder main body side in parallel to the recessed groove or protrusion 7, both cutting blade holders 2, 3 are provided with slits 9, 16 long in parallel directions to the recessed groove or protrusion 7, and both cutting blade holders 2, 3 are fixed to the holder main body 1 by a fixing bolt 21 inserted to the slits 9, 16. For the cutting blade holders 2, 3, a width 6 in a cutting reaction force applied direction can be enlarged to set strength and rigidity higher. Since a moving stroke of the cutting blade holders 2, 3 is large, a hole diameter range subject to processing is large.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal working machine, and more particularly to a holder for attaching a cutting edge for drilling to a rotating tool spindle of a machining center or a boring machine. The present invention relates to the holder used when performing machining by balancing a cutting reaction force by attaching a blade.

[0002]

2. Description of the Related Art A boring cutter attaches a cutting edge to an eccentric position of a rotating tool spindle and moves the tool spindle in a relative axial direction toward the workpiece while rotating the tool spindle, thereby removing an inner wall of a hole provided in the workpiece. It is used for processing to a predetermined size. When only one blade is attached to the tool spindle and processing is performed, the cutting reaction force acts unbalanced with respect to the center of the tool spindle, so the two cutting blades are arranged symmetrically with respect to the center line of the tool spindle. In particular, a method of performing machining while balancing the cutting reaction force is preferably employed when the diameter of the hole to be machined is large.

[0003] In order to mount the cutting blade at the eccentric position of the tool shaft, a holder is required, and the holder has a structure capable of adjusting and fixing the position of the cutting blade in the radial direction of the tool shaft. Drilling of a range of diameters can be performed with one holder. 5 to 7 show an example of a conventional balance cutting holder in which the position of the cutting blade 4 can be adjusted in the radial direction. In the drawings, 1 is a cylindrical holder body, 11 is a shank for fitting the holder body 1 to the tip of the tool shaft, and 2 is a cutting blade 4 at the tip.
Is a cutting blade holder fitted with. In the structure shown in FIG. 5, a plurality of guide grooves 24 extending in a direction perpendicular to the axis are provided on the end of the holder body 1, and a mountain-shaped projection 25 extending in the radial direction is formed integrally with the mounting surface of the cutting blade holder 2. A guide groove 26 that fits with the guide groove 24 on the holder body is provided.
The cutting blade holder 2 is fixed to the both sides of the chevron 25 with fixing bolts 21 in a state where the cutting blade holders 4 and 26 are fitted to each other. The cutting blade holder 2 has an elongated hole 28 for the fixing bolt 21 so that the position of the cutting blade 4 can be adjusted in the radial direction.

In the structure shown in FIG. 6, a wide dovetail groove 29 is formed at the tip of the holder body 1, and two or three axial screw holes are provided along the center of the dovetail groove. I have. The cutting blade holder 2 has a trapezoidal cross section, and includes a holding piece 30 having a trapezoidal cross section in the opposite direction to the cutting blade holder 2. In this structure, with the two cutting blade holders 2 fitted on both sides of the dovetail groove 29, the holding piece 30 is inserted between the cutting blade holders 2, 2, and the holding piece 30 is fixed with the fixing bolt 21.
Is fixed to the holder main body 1 to fix the cutting blade holder 2 to the tip of the holder main body 1.

In the structure shown in FIG. 7, a bar 33 provided with a radial guide 32 is attached to the tip of the holder body 1.
With a structure in which the cutting blade holder 2 is attached to both ends of the bar 33,
This structure is often used as a holder for processing a hole having a relatively large diameter.

[0006]

The cutting reaction force acting on the cutting blade 4 is mainly tangential, and this cutting reaction force acts to deflect the cutting blade holder 2 in a plane perpendicular to the axis. 5 and 6, the two cutting blade holders 2, 2 and the angled projection 25 are provided in a plane perpendicular to the axis on which the cutting reaction force acts.
Alternatively, since the structure is such that the two cutting blade holders 2 and 2 and the pressing piece 30 are arranged side by side, the width 6 of the cutting blade holder 2 cannot be increased, and the cutting reaction force acts on the cutting blade holder. There is a limit to increasing the strength or rigidity against the bending moment. Therefore, the cutting blade holder 2 cannot protrude too much from the chevron projection 25 or the dovetail groove 29, and the diameter range of the hole that can be machined by one holder is also limited. In addition, since the strength or rigidity against the cutting reaction force is likely to be insufficient, an accident occurs in which the cutting blade holder 2 breaks during heavy cutting.

On the other hand, in the structure shown in FIG. 7, the strength and rigidity of the bar 33 can be sufficiently increased, but a hole having a diameter smaller than the length of the bar 33 cannot be machined. In order to increase the diameter range of the hole that can be machined by the holder, it is necessary to have a structure that allows the cutting blade holder 2 to protrude greatly from the tip of the bar 33, and the strength of the fixed portion between the bar 33 and the cutting blade holder 2 is required. In order to secure rigidity, the length of the cutting blade holder 2 in the radial direction must be increased. However, when machining a hole having a small diameter, the bottom portions of the cutting blade holders on both sides collide with each other, so that it is impossible to machine a hole having a small diameter. For this reason, the structure shown in FIG. 7 is used as a holder for processing a hole having a relatively large diameter, and when processing a hole having a relatively small diameter, the structure shown in FIG. 5 or FIG. I have to use the holder.

The present invention has been made in view of the above-described prior art, and has a wide range of hole diameters that can be processed from a hole with a relatively small diameter to a hole with a large diameter and can be processed with a single holder. Another object of the present invention is to obtain a balance cut holder capable of sufficiently increasing strength and rigidity against a processing reaction force.

[0009]

According to a first aspect of the present invention, there is provided a balance cutting holder for a boring cutter, wherein two cutting blade holders extending in a direction perpendicular to an axis in opposite directions to an end of the holder body. It is characterized by being mounted in a superposed state.

According to a second aspect of the present invention, in the balance cut holder according to the first aspect, the holder body 1 is provided with one of the cutting blade holders 2 mounted on the tip end thereof in a state of being overlapped in the radial direction. Groove or ridge 7 to be guided to
The one cutting blade holder 2 includes guide means 18 for guiding the other cutting blade holder 3 mounted on the side opposite to the holder main body in parallel with the concave groove or the ridge 7. 2 and 3 are provided with elongated holes 9 and 16 extending in a direction parallel to the concave grooves or ridges 7, and both cutting blade holders 2 and 3 are provided with fixing bolts 21 which are inserted through the elongated holes 9 and 16 in the axial direction. And is fastened to the holder main body 1.

According to a third aspect of the present invention, there is provided the balance cut holder according to the second aspect, wherein elongated holes for inserting the fixing bolt are provided along both sides of the cutting blade holder. A temporary fixing bolt hole 13 is provided at the tip axis of the main body 1, and a second long hole 10 for inserting the temporary fixing bolt 20 into the center of the cutting blade holder 2 mounted on the holder main body side is formed as an elongated hole 9. And provided in parallel.

[0012]

The distal end of the cutting blade holder 2 mounted on the holder main body 1 while being superposed on the distal end of the holder main body 1 is:
The axial position of the cutting blade 4 attached to the tip, which is protruded in an L shape on the side opposite to the holder main body, coincides with the cutting blade 4 attached to the other cutting blade holder 3 that is superimposed.

The cutting blade holders 2 and 3 in the above-structured balance cut holder have a width 6 in a plane perpendicular to the axis on which a cutting reaction force acts, which is much larger than that of the conventional structure shown in FIGS. Since the stress with respect to the bending moment is theoretically proportional to the square of this width and the deviation is proportional to the cube of the width 6, the strength and rigidity can be sufficiently increased.

Further, since the two cutting blade holders 2 and 3 are in a parallel state, a large moving stroke in the radial direction can be taken, and the diameter range of the hole that can be processed by one holder can be widened. .

[0015]

Embodiments of the present invention will be described below with reference to embodiments shown in the drawings. The holder body 1 and the shank 11 have a structure similar to the conventional structure. A guide groove 7 having a U-shaped cross section in the radial direction is formed at the tip of the holder body 1, and the guide groove 7 is formed at the bottom of the guide groove. Five screw holes 12 for fixing bolts are provided in positions near and parallel to both sides, and screw holes 13 for temporary fixing bolts are provided in the axial direction at axial positions.

The cutting blade holders 2 and 3 have a first cutting blade holder 2 having a tip for mounting the cutting blade 4 protruding in an L-shape from the side of the holder main body when viewed from the side, and a tip end facing the holder main body. It is formed as a pair with the second cutting blade holder 3 projecting in an L shape.
The cutting blade 4 of the first cutting blade holder 2 is fixed to the tip of a portion protruding in an L shape at the tip, and the cutting blade 4 of the second cutting blade holder 3.
Are fixed to a bent portion of a portion protruding in an L shape. The distal end portions of the cutting blade holders 2 and 3 are notched in a substantially half as viewed from the axial direction, and a cutting edge fixing groove 5 having an L-shaped or U-shaped cross section for accommodating the cutting blade is provided at a further distal end portion of the remaining portion. Have been. In a state where the cutting blade 4 is fitted in the cutting blade fixing groove 5,
It is fixed to the cutting blade holders 2, 3 by a conventionally known fixing structure.

The fastening portion 2a of the first cutting blade holder 2 has a width 6 which is slidably fitted in a guide groove 7 provided in the holder body. Elongated holes 9, 9 through which fixing bolts pass are provided along both sides. Further, at the center of the fastening portion, there is provided a second slot 10 through which a temporary fixing bolt penetrates in parallel with the slot 9, and the slot 10 has a counterbore groove 14 for receiving the head of the temporary fixing bolt. Is provided.
Further, a guide groove 15 for guiding the second cutting blade holder is provided in a portion further away from the counterbore groove 14 and on the side opposite to the holder main body, in parallel with the side of the fastening portion 2a.

On the other hand, the fastening portion 3a of the second cutting blade holder 3 has a long hole 1 in a form corresponding to the long hole 9 of the first cutting blade holder.
A counterbore 17 for receiving the head of the fixing bolt is formed in a portion of the long hole on the side opposite to the holder main body. A sliding key slidably fitted in the guide groove 15 of the first cutting blade holder is provided at the surface of the second cutting blade holder on the holder body side, that is, at the center of the portion overlapped with the fastening portion of the first cutting blade holder. 18 is fixed parallel to the side of the fastening portion. Further, a fine adjustment screw 19 in a direction substantially parallel to the key 18 is screwed into the base end of the fastening portion of the second cutting blade holder.

In order to assemble the holder, the position of the cutting blade 4 with respect to the axis of the holder body 1 is determined by a micrometer or the like, and the guide grooves 7 of the holder body are temporarily fixed by bolts 20.
The position of the first cutting blade holder 2 in the inside is fixed. Next, the fastening portion of the second cutting blade holder 3 is overlapped thereon, the radial position of the cutting blade is determined, and the second cutting blade holder 3 is held by the fixing bolt 21 inserted through the slots 9 and 16. Fastened to the main body 1. At this time, the first cutting blade holder 2 is fastened while being sandwiched between the holder body 1 and the fastening portion 3a of the second cutting blade holder. The fine adjustment screw 19 is used to finely adjust the radial position of the cutting blade 4 of the second cutting blade holder 3.

When changing the diameter of the hole to be machined, the fixing bolt 21 and the second cutting blade holder 3 are removed, the temporary fixing bolt 20 is loosened, and the first cutting blade holder 2 is moved in the guide groove 7. The first cutting blade holder 2 with the temporary fixing bolt 20 at a new position.
Is fixed, the second cutting blade holder 3 positioned in the same procedure as above is positioned in the same manner as described above, and fastened together with the first cutting blade holder 2 with the fixing bolt 21.

The moving end on the small diameter side of the cutting blade holders 2 and 3 is formed by the base end 22 of the second cutting blade holder 3 or the head of the fine adjustment screw 19 and the L-shaped projecting portion of the tip of the first cutting blade holder. 23 is a position where the fixing bolt 23 contacts, and the moving end on the large diameter side is a fixing bolt 2
Reference numeral 1 denotes a position where the end comes into contact with the ends of the slots 9 and 16. At this time, a space is created between the base ends of the cutting blade holders 2 and 3 and the L-shaped protruding portion of the other cutting blade holder, and spacers 34 and 35 as shown in FIG. 1 are fitted into this space. Thereby, the rigidity of the cutting blade holder can be further increased. As described above, when the cutting blade holders 2 and 3 are pulled out to the outer diameter side for processing, the cutting blade holder 2 is fixed to the tip of the holder body 1 in a cantilever state. According to this, the width 6 of the cutting blade holder 2 can be increased,
Sufficient strength and rigidity against the cutting reaction force applied to the cutting blade 4 can be given, and the moving end on the small diameter side of the cutting blade holders 2 and 3 is also connected to the base end 22 of one of the fastening portions 3a or the fine adjustment screw 1
9 can be moved to the small diameter side until the head of the tip 9 comes into contact with the L-shaped projecting portion 23 at the other end, so that the diameter range of the hole that can be machined by one holder can be increased, and the number of types can be reduced. With this holder, it is possible to machine a hole having an arbitrary diameter from a small diameter to a large diameter.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an embodiment.

FIG. 2 is a side view of the embodiment.

FIG. 3 is a front view of the embodiment.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a side view of the first conventional structure.

FIG. 6 is a side sectional view of a second conventional structure.

FIG. 7 is a side view of a third conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Holder main body 2 Cutting blade holder 3 Cutting blade holder 7 Guide groove 9 Slot 10 Slot 13 Temporary fixing bolt screw hole 16 Slot 18 Sliding key 20 Temporary fixing bolt 21 Fixing bolt

Claims (3)

[Claims] 1. Two cutting blade holders (2, 3) extending in directions opposite to each other in the direction perpendicular to the axis are mounted on the tip of the holder body (1) in a state of being superposed in the axial direction. , Balance cut holder for boring cutter. 2. The holder body (1) is one of the cutting blade holders mounted on the holder body side in a state of being superimposed on the tip thereof.
(2) is provided with a groove or ridge (7) for guiding in the radial direction,
The one cutting blade holder (2) is used to connect the other of the cutting blade holders (3) mounted on the side opposite to the holder body to the concave groove or the ridge (7).
Guide means (18) for guiding in parallel with the
(2, 3) are provided with elongated holes (9, 16) extending in a direction parallel to the grooves or ridges (7), and both cutting edge holders (2, 3) are provided with these elongated holes (9, 16). The balance cut holder according to claim 1, characterized in that the balance cut holder is fastened to the holder body (1) by a fixing bolt (21) inserted through the holder body in the axial direction. 3. Slots (9, 16) through which fixing bolts (21) are inserted are provided along both sides of the cutting blade holder (2, 3), respectively.
A temporary fixing bolt hole (13) is provided at the tip axis of the holder body (1), and the cutting blade holder is attached to the holder body side.
3. The balance according to claim 2, wherein a second slot (10) for inserting a temporary fixing bolt (20) is provided in the center of (2) in parallel with the slot (9). Cut holder.