JPH0847803A - Throwaway type cutting tool - Google Patents

Abstract

PURPOSE:To facilitate the adjustment of outer diameter of a cutting edge, scarcely cause changes of deflection accuracy, and reduce costs. CONSTITUTION:A throwaway tip 9 having a cutting edge is fixed to a cartridge 10. The cartridge 10 is slidably fitted in grooves 6 provided at a peropheral surface of a tip face 5 of a boring bar 1 at equal intervals. A cap 25 is fitted in a recessed section 4a at the center of the tip face 5 through a spacer 24. A tapered portion 25b which is coaxial with an axis is provided at a tip of the cap 25 to bring a rear end face 22 of the cartridge 10 into contact with it and fix it. By changing with the space 24 having different thickness, a position in the axial direction of the tapered portion 25b moves, and by bringing the cartridge 10 into contact with it, the dimension of outer diameter of the cutting edge can be adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away type cutting tool such as a throw-away type boring bar equipped with a throw-away tip.

[0002]

2. Description of the Related Art In a conventional throw-away type boring bar, for example, a cartridge with a throw-away tip is mounted on the tip surface of the boring bar. It is fixed with a screw etc. at a position displaced in the direction. The ridgeline on the front side of the throw-away tip in the direction of rotation of the boring bar is a cutting edge, and the boring bar rotates about its axis to cut the work material into a hole having a desired inner diameter. A concave groove or a screw hole is formed on the tip end surface of the boring bar concentrically with the axis of the boring bar, and a cylindrical cap is fitted or screwed into the concave groove or the screw hole. When the cap is attached to the tip of the boring bar, each cartridge is fixed to the tip of the boring bar at the position where the rear end surface of the cartridge contacts the peripheral side surface of the cap, and the outer diameter of the cutting blade is set.

By moving the work material or the boring bar in the feed direction while rotating the boring bar, a hole having an inner diameter from the center of rotation of the boring bar tip surface to the tip of the cutting edge is formed in the work material. It is supposed to be processed. To change the inner diameter of the hole to be cut with the boring bar, loosen the screw fixing the cartridge and replace the cylindrical cap with one with a different outer diameter. If the cartridge is fixed at a position where the rear end portion is in contact with the outer peripheral surface of the cap by being displaced in the radial direction, the outer diameter dimension of the cutting blade is adjusted. Further, as another conventional example, there is a type of boring bar in which a cartridge with a tip or a throw-away tip is directly attached to the tip surface of the boring bar. In this case, the outer diameter of each cutting edge is adjusted by replacing the cartridge or the throw-away tip with a different size or changing the mounting position of the cartridge or the tip.

[0004]

However, in the case of the boring bar using the throw-away tip as described above, each time the inner diameter of the hole to be machined changes, another cap having a different outer diameter is used. If there are many types of inner diameters of the holes to be cut, it is necessary to prepare various types of caps corresponding to the inner diameters, which results in an increase in cost. Further, there is a drawback that the cap replacement work is complicated. or,
When replacing the cap, there is a manufacturing error in the cylindrical peripheral surface of each cap that the cartridge rear end contacts, or an installation error in the cap itself.Therefore, each time the cap is replaced, the position of the outer diameter of the cutting edge of each cartridge There is also a drawback in that adjustment and adjustment of deflection of each cutting edge are required, precision adjustment is complicated, and skill is required for adjustment work. In addition, for the boring bar of the type to which the cartridge and the throw-away tip are directly attached, various kinds of cartridges and throw-away tips with different dimensions must be prepared and replaced according to the change in the inner diameter of the hole to be cut. Or, the mounting position must be readjusted for each cartridge or chip individually, and as in the case described above, there are problems such as an increase in cost, necessity of readjustment of shake, and complexity of work. there were.

In view of such circumstances, the present invention makes it easy to change the outer diameter of the cutting edge, and even if the outer diameter of the cutting edge is changed, the runout accuracy of the outer diameter hardly changes, and the cost is reduced. It is an object of the present invention to provide a throw-away type cutting tool capable of suppressing the rise.

[0006]

A throw-away type cutting tool according to the present invention comprises a throw-away type cutting tool in which a throw-away tip having a cutting edge is fixed to a cartridge and the cartridge is attached to a tip of a tool body. A cartridge positioning member is detachably fixed to the center of the tip of the tool body via a spacer, and at least one of the contact surfaces of the cartridge positioning member and the cartridge is formed in a tapered shape, and the spacers have different thicknesses. It is characterized in that the outer diameter of the cutting blade can be adjusted by exchanging the cutting blade.

The surface of the cartridge positioning member that contacts the cartridge may be tapered. The cutting tool is characterized in that it is a boring bar that can be rotated about its axis.

[0008]

When the spacer having a different thickness is exchanged, the fixed position of the cartridge positioning member in the axial direction is displaced, so that the other abutting surface abuts on the tapered portion between the abutting cartridge and the cartridge. Thus, the fixed position of each cartridge can be continuously adjusted based on the cartridge positioning member, and the outer diameter of the cutting blade changes. Since the surface of the cartridge positioning member that contacts the cartridge is formed in a tapered shape,
After moving the cartridge positioning member in the axial direction,
The position is adjusted until the contact surface of the cartridge contacts the tapered contact surface. By adjusting the outer diameter of the cutting edge of the boring bar and performing rotary cutting, the inner diameter of the hole can be processed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 1 is a cross-sectional view of the tip of a throw-away type boring bar according to the first embodiment, FIG. 2 is a bottom view of the boring bar of FIG. 1, FIG. 3A is an enlarged plan view of a cartridge, and FIG. Enlarged perspective view of the away tip,
4A is an enlarged view of the cartridge portion of the bottom view of the boring bar shown in FIG. 2, and FIG. 4B is a side view of FIG. In the throw-away type boring bar 1 shown in FIGS. 1 and 2, a rear end convex portion of a boring bar main body (hereinafter referred to as a bar main body) 3 is fitted in a front concave portion of a shank portion 2, and further, the shank portion 2 and the bar main body. 3 is a central shaft portion, and one male screw portion and the other female screw portion are screwed with each other, and are concentrically and integrally fixed. The central hole 4 of the bar body 3 has a stepped, large-diameter central concave portion 4a at the front end side, and is open concentrically with the front end surface 5. Tip surface 5 of bar body 3
Has a tapered surface shape in which the periphery of the central concave portion 4a is inclined toward the base end side toward the outer peripheral side in the radial direction. A plurality of (five in FIG. 2) substantially rectangular parallelepiped concave grooves 6 are formed on the outer peripheral side of the central concave portion 4a at the front end surface 5, and each concave groove 6 has both radial end surfaces. Respectively open in the central recess 4a and the outer peripheral surface of the bar body 3. Further, chip pockets 7 for chip disposal are formed on the front end surface 5 of the bar main body 3 on the front side in the rotational direction of each groove 6.

A cartridge 10 having a throw-away tip 9 as shown in FIG. 3A, for example, is slidably fitted in the groove 6 so as to be slidable in a radial direction, and a screw 8 or the like is fastened. It is fixed by members. As shown in FIGS. 3 (A) and 3 (B), the throw-away tip 9 has a substantially square plate shape in a plan view, and has a screw hole 11 for screwing with a screw 11a or the like in the center thereof. Has been done. Moreover,
Two facing side faces 12, 1 of the throw-away tip 9
3, the pair of side surfaces 12, 12 form a flat inclined surface in which the distance between the lower surface 14 and the upper surface 15 of the chip 9 gradually widens, and the upper surface 15 and the two side surfaces 12, 12 facing each other intersect each other. The ridge sides are a pair of cutting edges 16, 16, and the other side surfaces 13, 13 are, on the contrary, flat inclined surfaces whose intervals gradually increase from the upper surface 15 to the lower surface 14 of the chip 9, and the lower surface. The ridges that intersect the two side surfaces 13 facing each other are a pair of cutting blades 17, 17. Therefore, the throw-away tip 9 can be used at four corners on the upper and lower surfaces.

Further, the cartridge 10 is formed in a substantially rectangular plate shape, and when mounted on the bar body 3, the tip 9 is fixed on the outer peripheral side of the upper surface 19 facing the seating surface and on the front side in the rotation direction. A seat portion 20 formed of a concave step portion is formed. Further, on the upper surface 19 of the bar body 3 on the axis side (hereinafter referred to as the rear end side), a long hole 21 for screwing to the front end surface 5 is drilled up to the seating surface. Extending in the radial direction. And the cartridge 1
On the rear end side of 0, two substantially rectangular plate-shaped corners are cut out to form cutouts 10a, 10a. As shown in FIG. 1, the side surface sandwiched between the notches 10a and 10a is a rear end surface 22 that is tapered (may be a vertical surface) by slightly inclining from the upper surface 19 inward of the seating surface. . The inclination angle of the rear end surface 22 is set according to the taper angle of the taper portion of the cap described later. In a state where the cartridge 10 is fitted and fixed in the tip groove 6 of the bar body 3, the inclined side surface 13 of the chip 9 is located on the tip side of the bar body 3, but the tip surface 5 is a tapered surface. Since the side surface 13 is parallel to the axis, the side surface 13 does not appear in the bottom view shown in FIG.
It does not hinder the cutting.

Further, on the tip end surface 5 of the bar body 3, a spacer 24 having an appropriate thickness is replaceably arranged in the central recess 4a, and a cap 25 (a part of which is fitted in the central recess 4a on the spacer 24). A cartridge positioning member) is provided. The cap 25 has a substantially cylindrical fitting portion 25a that fits in the central recess 4a, and is located outside the central recess 4a and has a diameter that gradually increases in the distal direction (outer than the fitting portion 25a. Tapered portion 25b (having a large diameter) is formed. The cap 25 is attached concentrically with the axis of the bar body 3. The taper angle α of the taper portion 25b is preferably in the range of more than 0 degree up to about 90 degrees on both end faces shown in FIG. 1, but may be larger than this. Then, from the tip of the taper portion 25b, a screw hole 26 that penetrates through the cap 25 and the spacer 24 and extends into the bar body 3 is formed substantially parallel to the axis of the bar body 3.
A screw 27 is screwed onto this, and the cap 25 is detachably fixed. The taper portion 25b includes a rear end surface 2 of the cartridge 10 fixed in each groove 6 of the front end surface 5.
2 are in contact with each other, and the spacer 24 is exchanged with one having a different thickness, whereby the fixed position of the cap 25 is advanced and retracted in the axial direction, and the rear end surface 22 of the cartridge 10 is tapered.
By adjusting the position in the radial direction so as to be in contact with 5b, the outer diameter of the cutting edge formed by the cutting edge 16 (17) of the throw-away tip 9 can be adjusted.

Since this embodiment is constructed as described above, when the outer diameter of the cutting edge 16 of the throw-away tip 9 is set prior to the machining and cutting of the hole of the work material by the boring bar 1, Loosen the screw 8 fixing the cartridge 10 to the tip surface 5 of the bar body 3, further remove the screw 27 to remove the cap 25 from the central recess 4a. In this state, the spacer 24 is replaced with one having a thickness corresponding to the outer diameter of the cutting edge 16 to be set as desired, and the cap 25 is fitted into the central recess 4a and fixed with the screw 27. As a result, the taper portion 25b of the cap 25 moves back and forth by a required amount in the axial direction. Then, each cartridge 10
In the state of being fitted in the groove 6, the rear end face 22 is tapered by the taper portion 25b by sliding a small amount in the radial direction along the groove 6 to adjust the position.
Tighten the screw 8 in the state of abutting against. In this way,
A plurality of cartridges 10 can be continuously fixed.

As a result, the outer diameter of the cutting blade 16 of the tip 9 fixed to each cartridge 10 is set to a desired size. Particularly, in the case of the present embodiment, the cap 25 that fits into the central recess 4 a is the tip surface 5 of the bar body 3.
Since the cartridges 10 are arranged concentrically with each other, if the respective cartridges 10 are fixed at the positions where the rear end surfaces 22 of the cartridges abut on the tapered portions 25b, the runout accuracy of the cutting blades 16 hardly changes.
In this case, since the adjustment of the runout accuracy of each cutting edge 16 only needs to be set at the beginning, the adjustment work does not require skill and the adjustment work of the cutting edge outer diameter can be completed in a short time. In this state,
By rotating the boring bar 1 to cut a hole in a work material, a hole having a desired inner diameter can be drilled. In this case, the inclination of the side surface 12 forming the cutting edge 16 constitutes a rake angle, the upper surface 15 constitutes a flank surface, and the intersecting angle between the side surface 12 and the upper surface 15 constitutes a cutting edge angle. In order to set the outer diameter dimension of the cutting edge 16 to another size, the spacer 24 having a different thickness may be appropriately changed according to the outer diameter dimension.

As described above, according to this embodiment, the cutting edge 1
When adjusting the outer diameter of 6, it is possible to finely adjust the outer diameter of the cutting edge by replacing it with a spacer 24 having a different thickness, and it is not necessary to individually adjust each cutting edge and all cutting edges can be continuously adjusted. Then you can do it easily. Moreover, the spacer 24
The replacement work of the cap 10 can be done in a short time, and even if the outer diameter of each cutting edge is changed, the taper portion 25b of the cap 25 and the cartridge 10 can be changed.
Since the rear end face 22 is not replaced, there are various advantages in that its deflection accuracy hardly changes, the adjustment work is easy, and no skill is required.

FIG. 5 is a partial sectional view of the tip portion of the boring bar showing the second embodiment of the present invention. In this embodiment, the cap 30 has no tapered portion, and the fitting portion 3
0a, a disk-shaped contact portion 30b having a diameter larger than that of the fitting portion 30a is concentrically formed on the tip side thereof. On the other hand, the rear end surface 22 of the cartridge 10 is formed in a tapered shape as in the first embodiment. Therefore, depending on the thickness of the spacer 24 fitted in the central recess 4a, the contact portion 30
The outer diameter of each cutting blade 16 can be finely adjusted by moving the cartridge 10 in the radial direction so that the position of b moves back and forth in the axial direction and the rear end surface 22 comes into contact therewith.

Contrary to the second embodiment, a tapered portion 25b is formed on the cap 25 as in the first embodiment, while a non-tapered corner, for example, is formed at the rear end of the cartridge 10, and this corner is formed. The part may abut on the tapered part 25b. In short, it is sufficient that at least one of the abutting portions of the cap and the cartridge has a tapered surface. Alternatively, instead of the tapered surface, one (a diameter) of one of the contact portions may be formed in a stepwise manner. This is also included in the taper portion in a broad sense. In addition, in the above-mentioned embodiment, the boring bar 1 is configured to be rotationally driven, but instead of this, the work material may be rotated to perform cutting.

[0018]

As described above, in the throw-away cutting tool according to the present invention, the cartridge positioning member is detachably fixed to the center of the tip of the tool body through the spacer, and the cartridge positioning member and the cartridge are separated from each other. At least one of the contact surfaces is formed in a tapered shape,
Since the outer diameter of the cutting edge can be adjusted by replacing the spacer with one with a different thickness, when adjusting the outer diameter of the cutting edge, you can change the outer diameter of the cutting edge by replacing the spacer with a different thickness. Adjustment is possible, and it is not necessary to individually adjust each cutting edge, and all cutting edges can be easily adjusted continuously. Moreover, the spacer replacement work can be completed in a short time, and even if the outer diameter of each cutting edge is changed, the contact surfaces of the cartridge positioning member and the cartridge are not replaced. It has various advantages that it is easy and requires no skill.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a boring bar according to a first embodiment of the present invention.

FIG. 2 is a bottom view of the boring bar shown in FIG.

FIG. 3A is a plan view of a cartridge, and FIG. 3B is a perspective view of a throw-away tip.

4A is a partially enlarged view of the cutting edge of FIG. 2, and FIG. 4B is a side view of FIG.

FIG. 5 is a boring bar according to a second embodiment of the present invention,
It is an enlarged view of the contact part of a cap and a cartridge.

[Explanation of symbols]

1 ... Boring bar, 3 ... Boring bar body, 4a ...
Central recessed portion, 9 ... Throw-away tip, 10 ... Cartridge, 16, 17 ... Cutting blade, 21 ... Oblong hole, 22 ... Rear end surface,
25 ... Cap, 25b ... Tapered portion.

Claims (3)

[Claims] 1. A throw-away type cutting tool in which a throw-away tip having a cutting edge is fixed to a cartridge, and the cartridge is attached to the tip of a tool body, in which a cartridge is provided in the center of the tip of the tool body via a spacer. The positioning member is detachably attached, and at least one of the contact surfaces of the cartridge positioning member and the cartridge is formed in a tapered shape, and the spacer is replaced with one having a different thickness. A throw-away type cutting tool characterized by adjusting the outside diameter. 2. The indexable cutting tool according to claim 1, wherein a surface of the cartridge positioning member that abuts on the cartridge is tapered. 3. The throw-away cutting tool according to claim 1, wherein the cutting tool is a boring bar which is rotated about an axis.