JPH07241701A - Throw away tip for rotary bite and rotary bite - Google Patents

Abstract

PURPOSE:To provide a throw away for improving machining accuracy of cutting by wholley equalizing the wear of a cutting edge accompanying extension of the continuous machining time of the throw away tip, and a rotary bite. CONSTITUTION:A throw away tip 20 is formed so that the upper and lower faces 20a, 20b are formed into a circle in the contour by plane view and in parallel with each other, a rotary axis is provided so as to pass on the center axis, cutting edges 22 are formed on the ridge lines between the above-upper and lower faces 20a, 20b and the circumferential face 20c adjacent to them and formed in rake faces on the upper and lower faces 20a, 20b, and a plurality of recessed parts 23 are annularly arranged in the vicinity of the cutting edges 22 of the upper and lower faces 20a, 20b. A rotary bite 30 is provided with the throw away tip 20, and a tool main body 31 to which the throw away tip 20 is rotationally movably fitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away tip for a rotary bite and a rotary bite provided with a throw-away tip for a rotary bite, which is driven by a body to be cut and rotates while cutting the body.

[0002]

2. Description of the Related Art Conventionally, in turning and boring systems, there are cutting tools used for machining the inside and outside diameters of a workpiece. As an example of this type of tool, for example, FIGS.
There is a cutting tool with a disc-shaped throw-away tip attached as shown in. In this cutting tool, a tip seat 2 having a substantially rectangular shape in plan view is formed at the tip of a tool body 1, and a disc-shaped throw-away tip 4 is seated on a bottom surface 3 of the tip seat. 4 is fixed by a lever 5 formed in an L shape. One end 6 of the lever 5 is inserted into a through hole 7 provided in the central portion of the throw-away tip 4 and the other end 8 of the lever 5 is inserted.
Is projected into a screw hole 9 formed at the tip of the tool main body 1, and a screw 10 is screwed toward the inner side of the screw hole 9 to rotate the whole body around a corner 11 as a fulcrum. The one end 6 strongly presses and restrains the throw-away tip 4 against the tip seat side wall surface 12.
Further, a locking claw 13 is provided at one end 6 of the lever 5, and the locking claw 13 is locked to a locking flange 14 projecting in the through hole 7 of the throw-away tip 4 to allow the throw-away. The away tip 4 is strongly attracted and constrained in the direction of the tip seat bottom surface 3 of the tool body 1. When the workpiece is cut, the cutting edge of the disk-shaped throw-away tip 4 fixed and held in this way is used for cutting, and when the cutting edge is worn or the cutting edge is broken, the lever The restraining force of the throw-away tip 4 by 5 is loosened, and the attachment angle position of the throw-away tip 4 is changed to perform cutting.

[0003]

By the way, in the above-mentioned conventional cutting tool, when the cutting portion of the throw-away tip 4 is worn, the cutting operation is stopped and the throw-away tip 4 is cut.
It is necessary to release the clamp, rotate the throw-away tip 4 by hand, and then re-clamp it, which causes a problem that continuous cutting cannot be performed. In addition, since the throw-away tip 4 is only partially worn, there is a problem that the wear rate is high and the continuous cutting time is short.

In view of the above problems, the present invention prolongs the continuous machining time of the throw-away tip by constantly maintaining the driven rotation of the machining object with respect to the machining object during cutting. An object of the present invention is to provide a throw-away tip for a rotary bite and a rotary bite using the same, in which the wear is evenly distributed to improve the machining accuracy of cutting.

[0005]

In the throw-away tip for rotary bite according to the first aspect of the present invention, the tip is formed in a disk shape, and the ridge line of at least one of the peripheral surface and the upper and lower surfaces is a cutting edge. A throw-away tip for a rotary bite that abuts the cutting edge on a rotating cutting object and cuts the cutting object while rotating while being driven by the cutting object. A plurality of concave portions or convex portions, which are located in the vicinity of the cutting edge and are arranged in an annular shape, are formed on a surface forming one or the other rake surface.

The rotary bite according to claim 2 has the throw-away tip for rotary bite according to claim 1 and a tool body to which the throw-away tip is attached, and the throw-away tip is the tool. It is characterized in that it is rotatably attached to the main body.

[0007]

In the throw-away tip for rotary bite according to the first aspect of the present invention, the contact between the object to be cut and the cutting edge and the contact between the chip of the object to be cut formed at the cutting edge and the concave or convex portion cause the object to be cut. The rotational force of the cutting body is transmitted to the throw-away tip, and the throw-away tip is driven to rotate relative to the rotation of the body to be cut.

In the rotary bite according to the second aspect, the throw-away tip for the rotary bite according to the first aspect is rotatably supported and used in the tool body.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to FIGS. First, a throw-away tip for a rotary bite of the present invention (hereinafter simply referred to as "throw-away tip") will be described with reference to FIG. Figure 1
Inside, reference numeral 20 is a throw-away chip of the present invention. In the throw-away tip 20, the upper and lower surfaces 20a and 20b, which have a circular contour in a plan view and are opposed to each other, are parallel to each other, and pass through on the central axis thereof.
A cutting edge 22 is provided on the ridge line between the upper and lower surfaces 20a and 20b and the outer peripheral surface 20c provided adjacent to the upper and lower surfaces 20a and 20b, respectively. Has been formed. The upper and lower surfaces 20a, 20b
Constitutes the rake face of the cutting edge 22, and a plurality of recesses 2 are provided in the vicinity of the cutting edge 22 on the upper and lower surfaces 20a, 20b.
3 are arranged in a ring shape.

A rotary bite 30 which holds the throw-away tip 20 in rotation will be described below. Figure 2
As shown in FIG. 5, the rotary bite 30 includes the throw-away tip 20 and a tool body 31 to which the throw-away tip 20 is attached, and the throw-away tip 20 has the tool body centered on the central axis thereof. It is rotatably attached to 31. The tool body 31 has a notch 34 formed by notching a tip surface 33 of a protrusion 32 formed at the tip, and one corner of the notch 34 is further notched into a fan shape in plan view,
Tip seat 3 on which the throw-away tip 20 is placed
5 is formed.

As shown in FIG. 3, a fitting portion 36 having a circular cross section is formed on the bottom surface of the tip seat 35.
A substantially columnar seat portion 38 having a collar portion 37 having a diameter substantially the same as that of the throw-away tip 20 is fitted and inserted, and the collar portion 37 is seated on the bottom surface of the tip seat 35. A lower shaft hole 39 is formed in the center of the surface of the flange portion 37 of the seat portion 38, and the shaft portion 21 of the throw-away tip 20 is rotatably fitted into the lower shaft hole 39 to allow the throw-away tip 20 to rotate. Is seated on the collar portion 37.

A clamp breaker 40 is fitted in the cutout portion 34 of the front end surface 33, and is fixed by a clamp screw 41. A part of the clamp breaker 40 extends to a region of the upper surface 20a of the throw-away tip 20 placed on the tip seat 35, and an upper shaft on which the shaft portion 21 of the throw-away tip 20 is rotatably fitted. A pressing portion 43 having a hole 42 is formed, and the throw-away tip 20 is pressed by this pressing portion 43.

A cylindrical brake collar 45 having a U-shaped cross section is provided between the clamp breaker 40 and the head portion 44 of the clamp screw 41. Clamp breaker 4
A hole 46 is formed in the peripheral region of the clamp screw 41 of 0, and the clamp screw 4 is formed in the hole 46.
An annular collar 47 having a T-shaped cross-section through which 1 passes is arranged,
The upper end thereof is in contact with the lower surface of the brake collar 45. A brake washer 48 is fitted and arranged on the upper surface of the clamp breaker 40 on the outer periphery of the annular collar 47, and a wave washer 49 is interposed between the brake washer 48 and the brake collar 45 in a compressed state. There is.

A cylindrical stepped recess 50 is formed around the clamp screw 41 of the cutout portion 34 of the protrusion 32, and the collar portion of the annular collar 47 is located in the wide portion, and the narrow portion is formed. A coil spring 51 that elastically presses the collar portion of the annular collar 47 is disposed on the outer periphery of the clamp screw 41, and urges the clamp breaker 40 in a direction away from the throw-away tip 20 via the annular collar 47. . Therefore, the pressing portion 43 of the clamp breaker 40 may be replaced with a brake washer 48 having a different thickness in order to adjust the pressing force.

The throw-away tip 20 attached to the tool body 31 is driven to rotate by the rotation of the workpiece W at a position where the workpiece W is cut and a desired cutting resistance is obtained. It is tilted at an appropriate angle.
(See Figure 4). In addition, as for the inclination of the throw-away tip 20, when the side rake angle α is less than −6 degrees, the rotational force for being driven by the rotation of the workpiece W is insufficient, and the side rake angle α is −40. If the degree is exceeded, the cutting resistance of the workpiece W increases, which hinders cutting. Therefore, it is necessary to set the angle within this range.

Since this embodiment is constructed as described above, a steel workpiece W as shown in FIG. 5 is turned at high speed using the rotary tool according to this embodiment. Then,
Since the side rake angle is set to a negative value, the throw-away tip 20 is driven to rotate by the cutting resistance of the workpiece W. Further, at this time, the chips generated by the cutting and traveling are brought into contact with the rake face of the tip 20, and the turning force of the chips in the traveling direction is applied to the throw-away tip 20. The chips that come into contact with the rake face press the concave portion 23 particularly by contacting the concave portion 23, and the rotational force thereof is efficiently applied to the throw-away tip 20. The throw-away tip 20 is a workpiece W.
Although the rotation is maintained due to the relationship between the cutting resistance and the lateral rake angle α, the delicate balance between the lateral rake angle α and the cutting resistance of the tip 20 is broken due to the change of the cutting condition, that is, the cutting resistance. When the driven rotation due to the cutting resistance cannot be obtained, a rotational force is applied to the throw-away tip 20 by the flow of chips to maintain the rotation, and the continuous machining time of the throw-away tip 20 is extended.

At this time, in the throw-away tip 20, the shaft portion 21 is guided by the lower shaft hole 39 of the seat portion 38 and the upper shaft hole 42 of the clamp breaker 40 to rotate (see FIG. 2). Also, throw away tip 2
Since 0 is elastically pressed by the pressing portion 43 of the brake collar 45, the driven rotation of the throw-away tip 20 due to the cutting resistance is suppressed so as not to become faster than necessary. In addition, throw away tip 20
The driven rotation speed of can be adjusted appropriately by the wave washer 49.

Further, the seat portion 38 has the fitting portion 3
Since it is rotatable within 6, the seat portion 38 that contacts the shaft portion 21 due to the cutting resistance acting on the throw-away tip 20.
When a part of the wall surface of the lower shaft hole 39 is worn, the fitting portion 36
By rotating the seat portion 38 inside and changing the bearing position of the cutting resistance, the accuracy of rotation and cutting of the throw-away tip 20 can be maintained.

As described above, according to the throw-away tip 20 of this embodiment, the contact between the workpiece W and the cutting edge 22,
And the rake face of the chips of the workpiece W formed by the cutting edge 22 particularly comes into contact with the recess 23, so that the workpiece W is driven to rotate relative to the rotation of the workpiece W by the recesses such as the groove D. Even if the workpiece W and the cutting edge 22 may stop the rotation of the tip 20 due to the cutting resistance generated by the side rake angle α, the rotation is maintained by the recess 23 of the tip 20 and the cutting edge 22 is worn. It progresses almost uniformly over the whole. As a result, the machining accuracy of cutting is improved, the life of the throw-away tip 20 is extended, and the machining accuracy of cutting can be maintained for a long time.

The throw-away tip 20 does not necessarily have to be formed in a cylindrical shape as in this embodiment. For example, the peripheral side surface may be tapered. Also,
The recess 23 does not have to be arranged along the cutting edge 22 as in the present embodiment. For example, it may be a large number of grooves extending radially from the central portions of the upper and lower surfaces 20a and 20b. Further, the throw-away tip 20 has upper and lower surfaces 20a, 2
It is also possible to provide a convex portion on the 0b surface and obtain the rotational force from the chips contacting the convex portion. In this case, on the upper surface of the brim portion 37 for clamping the throw-away tip 20 of the rotary bite 30 from above and below and the lower surface of the clamp breaker 40, the convex portion is formed at a portion corresponding to the locus of the convex portion due to the rotation of the throw-away tip 20. A movable groove is formed in advance.

[0021]

According to the throw-away tip for a rotary bite according to the first aspect of the present invention, the contact between the body to be cut and the cutting edge, and the chips of the body to be cut formed at the cutting edge and particularly the concave portion of the rake face or Due to the contact with the convex part, the rotational force of the work piece is transmitted to the throw-away tip, and driven rotation of the throw-away tip with respect to the rotation of the work piece is performed, resulting in a side rake angle when cutting the work piece. As compared with the case of using only the cutting resistance, the driven rotation of the rotary throw-away tip is more reliably maintained, the wear of the cutting edge progresses almost evenly, and the local progress of wear is prevented.

In the rotary bite according to the second aspect, the continuous cutting time of the throw-away tip is extended,
Since the local wear of the cutting edge is prevented, the machining accuracy of cutting can be maintained for a long period of time.

[Brief description of drawings]

FIG. 1 is a perspective view showing a throw-away tip for a rotary bite of the present invention.

FIG. 2 is a perspective view of a main part showing an embodiment of a rotary bite of the present invention.

3 is a vertical cross-sectional view of the rotary bite in FIG.

FIG. 4 is a diagram of a rotary bite according to an embodiment of the present invention.
It is a principal part perspective view seen from a different direction.

FIG. 5 is a perspective view showing a relationship between a rotary bite and a body to be cut according to an embodiment.

FIG. 6 is a perspective view showing the operation of the rotary bite and the rotary bite of the present invention.

FIG. 7 is a plan view showing a conventional throw-away tip and a cutting tool.

8 is a vertical cross-sectional view showing the throw-away tip and the cutting tool of FIG. 7. FIG.

[Explanation of symbols]

 20 Throw-away tip 20a Upper surface 20b Lower surface 20c Circumferential surface 21 Shaft portion 22 Cutting edge 23 Recessed portion 30 Rotary bite 31 Tool body W Object to be cut

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Takahashi 1511 Furumagi, Ishishita-machi, Yuki-gun, Ibaraki Prefecture Mitsubishi Materials Corporation Tsukuba Works

Claims (2)

[Claims] 1. A disc-shaped disc having a ridge line on at least one of the peripheral surface and the upper and lower surfaces thereof serving as a cutting edge, and the cutting edge is brought into contact with a rotating workpiece to be cut. In a throw-away insert for a rotary bite that rotates while being driven by a cutting body to perform cutting of the body to be cut, in the surface forming one of the upper and lower surfaces or the other rake surface, the vicinity of the cutting edge is provided. The throw-away tip for a rotary bite, which is formed by arranging a plurality of concave portions or convex portions in an annular shape. 2. A throw-away tip for rotary bite according to claim 1, and a tool body to which the throw-away tip is attached. The throw-away tip is rotatably attached to the tool body. A rotary bite that is characterized by