JPH063502U - Cutting tools - Google Patents

Abstract

(57) [Summary] [Structure] The throw-away tip 14 mounted on the tip of the tool body 11 has a rough machining blade 16 extending from the tip of the tool body 11 toward the base end side, and a nose portion on the rough machining blade 16. 1
8 and a finishing blade 17 extending in a direction intersecting the longitudinal direction of the tool body 11 are formed. The peripheral surface 14B of the throw-away tip 14 that is a rake face that is continuous with both the rough cutting blade 16 and the finishing processing blade 17.
Is formed in a direction in which it gradually recedes with respect to the reference plane S passing through the nose portion 18 as it is separated from the nose portion 18, and a positive rake angle is given to the roughing blade 16 and the finishing blade 17, respectively. . [Effect] Since roughing and finishing can be performed at the same time, and moreover, the finishing blade 17 has a cutting edge shape with an extremely large radius of curvature R, so that a finishing surface superior depending on the cutting conditions during roughing Can be obtained.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cutting tool such as a cutting tool used for turning.

[0002]

[Prior art]

 6 to 8 show an example of such a cutting tool, in which a cutting edge used for cutting is formed on a throw-away tip (hereinafter referred to as a tip) which is detachably attached to the tip of a tool body. In addition, it shows a throw-away type byte. In these drawings, the tool main body 1 has a substantially rectangular column shape, has a shank portion 2 on the base end side thereof, and a tip mounting seat 3 is formed on the upper surface of the tip end portion so as to be recessed from the upper surface by one step.

The chip 4 mounted on the chip mounting seat 3 has a rectangular flat plate shape in the examples shown in these figures, and the end face 4 A facing the chip thickness direction is directed upward, and 4A and one peripheral surface 4B disposed around the end surface 4A are directed toward the feed direction F side (the lower side in FIG. 6) of the cutting tool, and an arc-shaped nose portion cut at one corner of the end surface 4A. The blade 4C is projected to the tip side of the tool, and is fixed to the chip mounting seat 3 via a sheet member 6 by a known clamp mechanism 5 such as a lever lock. Then, by feeding the tool body 1 in the feed direction, the work material is cut by the cutting edge 4D formed on the ridge line intersecting with the end surface 4A and the one peripheral surface 4B, and at the same time, the cutting edge 4D. The nose portion cutting edge 4C connected to the above makes the machined surface cut smooth.

[0004]

[Problems to be solved by the device]

 By the way, it is known that the theoretical finished surface roughness h of this machined surface is determined by the feed amount f of the cutting tool and the radius of curvature R of the arc formed by the nose portion cutting edge 4C. That is, as shown in FIG. 9, when the feed amount fz per revolution of the work material W becomes large, the interval between the parts to be cut by the nose part cutting edge 4C becomes large, and accordingly, it is formed on the finished surface. The distance between the bottom of the valley and the top of the peak, that is, the finished surface roughness h also becomes large. Further, when the radius of curvature R of the nose portion cutting edge 4C becomes small, the inclination of the valley or the peak becomes large, and the distance between the valley bottom and the peak becomes large and the finished surface roughness R also becomes large. . By the way, it is known that the finished surface roughness h is approximately proportional to the square of the feed amount f and inversely proportional to the radius of curvature R. Therefore, in such a cutting tool, it is necessary to reduce the feed amount f or set the curvature radius R of the nose portion cutting edge 4C large in order to obtain good finished surface accuracy.

However, while it is difficult to form the nose portion cutting edge 4C having an extremely large radius of curvature R on the chip 4 having a limited size, it is irreversible to reduce the feed amount f and the machining efficiency is unavoidable. Will be reduced. For this reason, in the past, it was attempted to obtain a good finished surface while preventing the reduction in machining efficiency by roughing the work material once with a relatively large feed amount and then performing finishing with a relatively small feed amount. However, in such processing that requires two steps, process management and tool management become extremely complicated, and there is an inherent limit to suppressing a decrease in processing efficiency.

Further, as such a cutting tool, for example, as disclosed in Japanese Patent Publication No. 3-41282, the cutting edge of the tip is set in the tangential direction of rotation of the work material, that is, in the direction of main motion. There is also proposed a throw-away type cutting tool in which the radius of curvature of the cutting edge is increased in a pseudo manner with respect to the finished surface by arranging it so that it is inclined at a single time. The end of the insert that faces the thickness direction and the peripheral surface intersects the one cutting edge formed on the ridge line, which is used for both roughing and finishing at the same time. The problem arises that the load acts. In addition, the tip of this cutting tool is of a negative type, and in order to give a front clearance angle to the end face facing the tool tip side, the front rake angle of the cutting edge must be set to the negative angle side, As a result, the cutting resistance is increased and the load on the cutting edge becomes even greater.

[0007]

[Means for Solving the Problems]

 The present invention has been made in order to solve such a problem, and includes a rough machining blade at the tip of the tool body from the tip of the tool body toward the base end, and a nose portion on the rough machining blade. And a finishing cutting edge extending in a direction intersecting the longitudinal direction of the tool body, and the rake face that is continuous with both the roughing cutting edge and the finishing cutting edge is separated from the nose portion with the nose. It is characterized in that it is formed in a direction in which it gradually recedes with respect to a reference plane that passes through the part, and that each of the rough cutting edge and the finishing edge has a positive rake angle.

[0008]

[Action]

 According to the cutting tool having such a configuration, first, the rough machining blade that goes from the tool tip toward the base end is provided at the tip of the tool body, and the direction in which the rough machining blade intersects the longitudinal direction of the tool body through the nose portion. And a finishing blade which is continuous with. That is, the rough cutting edge extends in the radial direction with respect to the rotating shaft of the rotating work material, and the finish cutting edge passes through the nose located at the tip of the rough cutting edge to the finished surface of the work material. Since it is arranged along the contacting flat surface, the finished surface of the work material cut by the roughing blade to approximately the specified size is connected to the rear side of this roughing blade in the tool feed direction. Finishing is done with the working blade, and it is possible to perform roughing and finishing at the same time.

Further, as the rake face continuing to both the rough cutting edge and the finish cutting edge is separated from the nose portion, a reference plane passing through the nose portion, that is, a direction of the main motion (work material) passing through the nose portion. It is formed so as to recede with respect to a plane perpendicular to the (rotational direction of), so that the rough cutting edge and the finishing cutting edge are also inclined so as to recede from the reference plane as they move away from the nose part. Will be formed. Here, the finishing blades are arranged along the tangent plane that contacts the finishing surface of the work material as described above, and since such finishing cutting blades are arranged further inclined, for example, If the position of the core height of the processing blade is set to the center of the finishing blade, the distance from the rotary shaft of the work material to the tip of the finishing blade is the finishing blade that matches the core height. Is the smallest in the central part of the blade, and conversely, is slightly larger than the distance in the central part at both ends of the finishing blade. Therefore, with the cutting tool configured as described above, the state is the same as when a finished surface is cut with a convex curved cutting edge having an extremely large radius of curvature, and therefore the finished surface roughness is increased even if the feed amount of the tool is increased. It is possible to obtain an excellent finished surface with high quality.

Further, in the cutting tool having the above structure, the rake face is formed so as to be inclined so as to recede with respect to the reference plane passing through the nose portion as described above. A positive rake angle will be given. For this reason, the sharpness of both processing blades is improved, and the cutting load acting on the cutting blades can be reduced.

[0011]

【Example】

 1 to 3 show a throw-away type bite as an embodiment of the present invention. In these drawings, reference numeral 11 denotes a tool body which is formed of steel or the like and is held horizontally and in a direction vertical to the rotation axis O of the work material W, and is attached to the machine tool side at the base end portion thereof. The shank portion 12 is provided in the shape of a quadrangular prism. The tip portion of the shank portion 12 faces the upper side of the tool body 11 and the corner toward the tool feeding direction F, and the tip side of the tool body 11 extends from the base end side. The tip mounting seat 13 is formed so as to be retracted one step.

The tip 14 mounted on the tip mounting seat 13 is made of a hard material such as cemented carbide, and in this embodiment, it has a rhombic flat plate shape in a plan view from the thickness direction. An attachment hole, through which the clamp screw 15 is inserted, is provided from the center of the one end face 14A of the diamond shape facing the thickness direction of the chip. In the tip 14, the end face 14A is directed to the tool tip side, the acute angled corner C of the end face 14A is located above and on the tool feeding direction F side, and the edge ridges of the end face 14A are aligned with each other. Of the peripheral surface of the continuous tip 14, one of the peripheral surfaces 14B and 14C continuous with a pair of side ridges intersecting with the corner C is directed upward and the other is directed toward the tool feeding direction F side. It is attached to the seat 13 and is fixed to the tool body 11 by the clamp screw 15.

It should be noted that the pair of side ridges of the end surface 14A intersecting each other at the corner portion C recedes downward or rearward in the tool feeding direction F as the distance from the corner portion C increases as shown in FIG. It is arranged in the direction to. Therefore, in the present embodiment, the peripheral surface 14B facing upward when the chip 14 is mounted is not restricted in any direction on the peripheral surface 14B even if it is separated from the tip of the corner C. With respect to the reference plane S passing through the tip, that is, inclining in the direction of receding downward with respect to the horizontal plane that passes through the tip of the corner portion C and is perpendicular to the main motion direction (rotation direction of the work material). In this embodiment, the peripheral surface 14B has an inclination angle α toward the rear side in the tool feeding direction F as shown in FIG. 2 and as shown in FIG. 3 at the tool base end side. It is inclined at an inclination angle β. By the way, in the present embodiment, these inclination angles are set such that the inclination angle α is 20 ° and the inclination angle β is 15 °. In the present embodiment, of the pair of side ridges intersecting at the corner C, the side ridge continuing to the peripheral surface 14C facing the tool feeding direction F is the corner C as shown in FIG. It is also arranged so as to recede toward the tool base end side with respect to the vertical plane passing through the tip of the corner C as it is separated from the end face C, whereby the clearance angle φ is given to the end face 14A. Become.

In the present embodiment, among the side ridges that intersect at the corners C, the roughing blade 16 is formed at the side ridge that is continuous with the peripheral surface 14C and the side that is continuous with the peripheral surface 14B. A finishing blade 17 is formed on the ridge. Therefore, the peripheral surface 14 B facing upward is a rake face which is continuous with the roughing blade 16 and the finishing blade 17, and at the tip of the corner C, the roughing blade 16 and the finishing blade 17 are formed. Thus, the nose portion 18 that intersects is formed. In addition, as the peripheral surface 14B is arranged so as to be inclined as described above, as the rake face is also separated from the nose portion 18, a direction in which the peripheral surface 14B recedes downward with respect to the reference plane S passing through the nose portion 18. Therefore, the rough cutting edge 16 and the finishing edge 17 are given a positive rake angle. The rake angle of the finishing blade 17 is equal to the inclination angle α as shown in FIG. 2, and the rake angle of the roughing blade 16 is the inclination angle β as shown in FIG. Is set equal to.

In the cutting tool having such a configuration, as shown in FIGS. 1 and 3, the rough cutting blade 16 is arranged along the radial direction with respect to the rotation axis O of the workpiece W, and the finishing blade 17 is cut. Each of them is arranged along a tangent plane that is in contact with the finished surface P of the work material W. Then, the position H of the core height of the cutting tool at this time is aligned with the central portion C of the finishing processing blade 17 as shown in FIG. 4, for example. In FIG. 4, reference numeral Dr indicates the depth of cut by the roughing blade 16, and reference numeral Df indicates the depth of cut by the finishing blade 17. Therefore, by moving the tool body 11 in the tool feeding direction F while rotating the work material W around the rotation axis O, the outer circumference of the work material W is made to have a substantially predetermined forming dimension by the roughing blade 16. At the same time as the roughing is performed by shaving off to the end, the roughened surface is finished by the finishing blade 17 which is connected to the rear side of the roughing blade 16 in the tool feed direction F. P is formed. That is, according to the cutting tool having the above configuration, it is possible to perform rough machining and finishing at the same time, and the machining efficiency is significantly higher than that in the case where conventional rough machining and finishing are performed in separate steps. It is possible to improve and reduce the labor required for process control and tool management.

On the other hand, the finishing blade 17 is arranged along the tangent plane that is in contact with the finishing surface P as described above, and is separated from the nose portion 18 with respect to the reference plane S passing through the nose portion 18. And is inclined so as to retreat downward. In the present embodiment, the position of the core height of the cutting tool is set so as to coincide with the central portion C of the finishing blade 17, so that the finishing blade from the rotary shaft O of the work material W is cut. The distance to the cutting edge of 17 is the smallest in the central portion C, and becomes slightly larger as it goes away from the central portion C toward both ends of the finishing blade 17, and this is from the side of the work material W. As can be seen, as shown in FIG. 5, the state is the same as when finishing is performed by a convex curved cutting edge having an extremely large radius of curvature R.

The radius of curvature R is appropriately determined depending on the radius of gyration of the finished surface P of the workpiece W, the inclination angle α of the finishing blade 17, the position of the core height, and the like. Even so, it is possible to obtain a radius of curvature much larger than the half radius of curvature of the cutting edge of the nose portion that can be formed in a chip of a limited size as in the past. Thus, according to this embodiment, excellent finishing surface accuracy can be obtained even under the cutting conditions of high cutting speed and high feed rate during roughing, so that roughing and finishing are performed as described above. Even when they are performed simultaneously, it is possible to perform cutting according to the cutting conditions for rough machining, and it is possible to obtain a good finished surface while shortening the cutting time.

Further, in the present embodiment, the rake face that is continuous with the roughing blade 16 and the finishing blade 17 is retracted downward with respect to the reference plane S passing through the nose portion 18 as it is separated from the nose portion 18. Thus, the roughing blade 16 and the finishing blade 17 have a normal shape depending on the inclination angle given to the peripheral surface 14B which is the rake face. The rake angle α and the positive rake angle β are also given to the finishing blade 17, respectively. Therefore, according to this embodiment, it is possible to improve the sharpness of any of the roughing blade 16 and the finishing blade 17, and the cutting edge can be used even under the above-mentioned roughing cutting conditions. The cutting load that acts can be reduced and the life of the cutting edge can be extended.

In the present embodiment, the inclination angles α and β are set to 20 ° and 15 °, respectively, and the rake angles corresponding to them are given to the roughing blade 16 and the finishing blade 17, respectively. The proposed rake angle is not limited to these values. However, in order to more effectively bring out the above-described operational effects, it is desirable that these inclination angles α and β are set in the ranges of 15 ° to 30 ° and 10 ° to 20 °, respectively. Further, in the present embodiment, the roughing blade 16 and the finishing blade 17 are formed on each side ridge of the tip 14 which is detachably attached to the tip of the tool body 11; The present invention may be implemented not only in a cutting tool, but also in a cutting tool bit in which a cutting edge is directly formed in the tool body or a cutting tool bit in which a tip is fixed to the tool body by brazing or the like.

[0020]

[Effect of device]

 As described above, according to the present invention, the tool body is provided with the roughing blade and the finishing blade, and the roughing and the finishing can be performed at the same time, and the finishing blade has an extremely large radius of curvature. Since it has a blade shape, an excellent finished surface can be obtained depending on the cutting conditions during rough machining. Therefore, it is possible to improve the machining efficiency by shortening the machining time while maintaining the high finishing surface accuracy, and it is possible to simplify the process management and the tool management. Furthermore, both cutting edges are given a positive rake angle, so even under cutting conditions such as high cutting speed and high feed rate in rough machining, the load acting on the cutting edge is reduced and the life of the cutting edge is improved. Can be extended.

[Brief description of drawings]

FIG. 1 is a plan view of a throw-away type bite according to an embodiment of the present invention.

2 is a front view from the tip side of the embodiment shown in FIG. 1. FIG.

FIG. 3 is a side view from the tool feeding direction F side of the embodiment shown in FIG.

FIG. 4 is an enlarged view of a cutting edge portion showing a state of cutting a work material W according to the embodiment shown in FIG.

5 is a diagram showing a finished surface P of a work material W cut by a finishing blade 17 of the embodiment shown in FIG.

FIG. 6 is a plan view showing a conventional throw-away tool.

FIG. 7 is a side view of the tip portion of the conventional example shown in FIG. 6 as viewed in the X direction.

FIG. 8 is a front view of the tip portion of the conventional example shown in FIG. 6 as viewed in the Y direction.

9 is an enlarged view showing a state in which a work W is cut by the conventional example shown in FIG.

[Explanation of symbols]

 11 Tool body 12 Shank part 13 Tip mounting seat 14 Tip 14B Peripheral surface (rake surface) facing upward of tip 14 Roughing blade 17 Finishing blade 18 Nose part F Tool feed direction W Workpiece material P Finishing surface O Machining Rotational axis of material W S Reference plane passing through nose portion H Position of core height R Radius of curvature formed by finishing blade 17 α Inclination angle of finishing blade 17 with respect to reference plane S Inclination of roughing blade 16 with respect to reference surface S Horn

Claims (2)

[Scope of utility model registration request] 1. A rough machining blade extending from a tip of the tool body toward a base end side of the tool body, and a rough machining blade connected to the rough machining blade via a nose portion in a direction intersecting the longitudinal direction of the tool body. A rake face that has an extending finishing blade and that extends to both the roughing blade and the finishing blade is formed in a direction that gradually recedes with respect to a reference plane that passes through the nose portion as it is separated from the nose portion. And
A cutting tool characterized in that the rough cutting edge and the finish processing edge are each provided with a positive rake angle. 2. A polygonal flat plate-shaped throw-away tip is removably attached to the tip of the tool body with its end face facing the tip thickness direction facing the tip of the tool. One of the peripheral surfaces of the throw-away tip arranged around the end surface facing the depth direction is the rake surface, and the one peripheral surface and the other peripheral surface adjacent to the one peripheral surface. The rough processing blade is formed at the ridge line portion intersecting with the one peripheral surface, and the finish processing blade is formed at the intersection ridge line portion between the one peripheral surface and the end face facing the chip thickness direction. The cutting tool according to claim 1, wherein: