JPH0574711U - Indexable cutting tool - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a throw-away type cutting tool with high cutting edge position accuracy of the throw-away tip and strong clamp strength. A tip seat 26 having a seat surface 28 and a side wall 34 is formed at the tip of the tool body 24, and a seat member 36 and a throw-away tip 20 are placed on the tip seat 26. It is clamped and fixed by a clamp piece 60 that is tightened by a clamp bolt 62.
The seat member 36 has its upper convex portion 38 engaged with the throw-away tip 20 through hole 22, and its rear end side is biased toward the tool body front end side by a spring 44.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvement of a tip mounting structure of a throwaway type cutting tool in which a throw-away tip (hereinafter referred to as "tip") is attached to a tip seat by using a clamp piece such as a bite or a boring bar. .

[0002]

[Prior Art]

 FIG. 7 shows an example of a conventional tip mounting structure of a throw-away type cutting tool of this type. A pin 8 for projecting a head portion 8a above the tip seat 6 is screwed into a screw hole 4 formed on the front end side of the tool body 2 of the throw-away cutting tool (bite). The head portion 8a is located inside the through hole (recess) 10a formed in the chip 10. On the other hand, on the rear end side of the screw hole 4 of the tool main body 2, a positioning member 16 and a clamp piece 18 are arranged above the screw hole 12, and further penetrate the inner diameter portions of the positioning member 16 and the clamp piece 18. A clamp pin 14 for screwing the front end portion into the screw hole 12 is provided. The tip portion 18a of the clamp piece 18 is brought into contact with the upper surface of the chip 10. Note that the recess formed in the chip 10 may not penetrate the chip 10 in the thickness direction.

In the throw-away type cutting tool as described above, when the clamp screw 14 is screwed in, the positioning member 16 is pushed out by the tapered portion 18b inside the clamp piece 18, and the positioning member 16 and the pin 8 are pushed. The tip 10 is sandwiched between the tip 10 and the head 8a of the head, and the tip 10 is positioned in a direction parallel to the tip seat 6. At the same time, the tip 10 is pressed in the direction of the tip seat 6 by the tip end portion 18a of the clamp piece 18, and thereby positioned in the thickness direction.

[0004]

[Problems to be solved by the device]

 By the way, in the conventional throw-away type cutting tool as described above, the tip 10 is formed by the head 8a of the pin 8 located inside the through hole 10a and the positioning member 16 located outside the through hole 10a. , Is positioned in a direction parallel to the tip seat (seat surface) 6. Therefore, a slight error may occur in the position of the cutting edge of the tip 10 due to an accuracy error of the through hole 10a, a bending of the pin 8, a shape error of the positioning member 8, etc., and the accuracy of the cutting edge position can be further improved. A chip mounting structure was required. Further, in the above-mentioned throw-away type cutting tool, since the clamping strength of the tip 10 depends on the rigidity of the pin 8, the positioning member 16, etc., a tip mounting structure that is more rigid and can improve the clamp strength is also provided. It was requested. The present invention aims to solve the above problems.

[0005]

[Means for Solving the Problems]

 According to the present invention, a chip having a recessed portion extending in the thickness direction at a substantially central portion is placed on a chip seat provided in a tool body, and the chip is provided by a clamp piece provided in the tool body. In a throw-away cutting tool clamped and fixed to a tool body, a side wall of the tip seat or a part of the side wall of the tip seat serves as a positioning surface with which the side surface of the tip abuts, and the seat surface of the tip seat is It is formed so as to incline in a direction in which the depth of the tip seat gradually decreases toward the tip side of the tool main body with respect to the tip clamping direction of the clamp piece. A seat member is provided, which gradually decreases toward the tip side of the main body, a convex portion that engages with the concave portion of the chip is formed on the upper surface, and a lower surface is slidably formed on the seat surface of the chip seat. Between the sheet member and the tool body, it is characterized in that the biasing means is provided which urges the sheet member to the tool body distal end.

[0006]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 2 and 3 show a throw-away type cutting tool (throw-away type cutting tool) according to an embodiment of the present invention, and FIG. 1 shows a sectional view taken along the line AA of FIG.

The throw-away type cutting tool shown in these drawings uses a diamond-shaped flat plate-shaped tip 20 having a through hole (recess) 22 formed in the center thereof as a cutting blade.

A tip seat 26 for mounting the tip 20 is formed at a corner of the tip of the tool body 24, and a lower portion of the tip seat 26 has a penetrating hole that allows the lower space 27 and the tip seat 26 to communicate with each other. The hole 29 is formed.

The tip seat 26 is one in which the corners of the tool body 24 are recessed as shown in FIG. 1, and the seat surface 28 is a smooth surface and the side wall extending upward from the end of the seat surface 28. 34 and. The side wall 34 is composed of an upper surface 30, a step surface 31 continuous with the upper surface 30, and a lower surface 32 continuous with the step surface 31. The upper surface 30 is a positioning surface that abuts on the side surface of the tip 20 without any gap and accurately determines the position (blade position) in the direction parallel to the seat surface 28 of the tip 20.

The seat surface 28 is formed so as to be inclined with respect to the tip clamp direction in a direction in which the tip seat depth gradually decreases toward the tip side of the tool body 24. Here, in the present specification, the tip clamp direction means a direction in which the chip 20 is pressed by the later-described clamp piece 60, and to be precise, it changes by a minute angle according to the tightened state of the clamp piece 60. However, since it can be regarded as almost constant in the minute movement range of the clamp piece 60 during the fixing operation of the chip 20, its average direction is defined as the chip clamp direction. In the present embodiment, the tip clamping direction is the direction perpendicular to the upper surface 24a of the tool body 24 (direction of arrow B in FIG. 1) and coincides with the axial direction of the clamp bolt 62 described later. The angle θ formed by the seat surface 28 and the axis of the clamp bolt 62 (chip clamp direction) is in the range of 45 to 75 °.

A seat member 32, whose thickness gradually decreases toward the tip side of the tool body 24, is placed on the seat surface 28 of the tip seat 26. A shaft-shaped convex portion 38 that engages with the through hole 22 of the chip 20 is formed in an upper portion of the sheet member 32 at a substantially central portion, and a screw hole 40 is formed in a lower portion thereof. The diameter of the convex portion 38 is smaller than that of the through hole 22. Further, a concave portion 42 that opens to the side is formed on the rear end side of the seat member 36, and a spring 44 (corresponding to a biasing means) is fixed to the concave portion 42 at one end side thereof and the other end side thereof. Is projected outward. The threaded portion of the bolt 46 loosely inserted into the through hole 29 is screwed into the threaded hole 40 in the lower portion of the seat member 36, and the chip 20 has the through hole 22 in the upper portion of the sheet member 20. And the convex portion 38 are engaged with each other. The axis of the bolt 46 is perpendicular to the lower surface of the seat member 36.

On the other hand, on the rear end side of the tip seat 26 of the tool body 24, a screw hole 48 whose axis extends perpendicularly to the upper surface 24 a of the tool body 24 is formed. A cylindrical hole portion 50 having a diameter larger than that of the screw hole 48 is formed therein, and a spring 52 is inserted so that one end portion is locked at a step portion between the hole portion 50 and the screw hole 48. Further, on the rear end side of the screw hole 48 of the tool main body 24, a pin 56 is inserted into a hole portion 54 formed by opening in the upper surface 24a, and a substantially flat plate having a through hole 58 formed in the central portion. The clamp piece 60 is shaped like a recess 60a formed at one end of the clamp piece 60 and is engaged with the pin 56, and the other end is in contact with the chip 20. Then, the clamp bolt 62 is inserted into the through hole 58 of the clamp piece 60, and the screw portion on the tip end side is screwed into the screw hole 48.

When the insert 20 is attached to the tool body 24 in the throw-away cutting tool having the above-described configuration, first, the clamp bolt 62 and the bolt 46 are loosened, and then the convex portion 38 of the sheet member 36 is attached. The through hole 22 of the chip 20 is engaged (state of FIG. 4). At this time, the gap h0 between the lower end of the clamp piece 60 and the upper surface of the convex portion 38 of the sheet member 36 is equal to or larger than the thickness of the chip 20.

Next, when the clamp bolt 62 is gradually tightened, the sheet member 36 slides on the seat surface 28 toward the rear end side of the tool body 24, and the tip 20 of the tool body 24 is also moved. Slide in the direction of the rear end (the direction of arrow C in Fig. 4). FIG. 5 shows an example of a state in which the tip 20 has not been completely clamped at this time. The distance D1 between the lower end of the clamp piece 60 and the upper surface 24a of the tool body 24, the lower surface 32 and the sheet member. The distance L1 from the side surface of 36 is smaller than the distances D0 and L0 in FIG. Further, the gap m1 formed between the rear end side portion 38a of the convex portion 38 of the sheet member 36 and the through hole 22 is not yet zero.

When the clamp bolt 62 is further tightened, the side surface of the chip 20 comes into close contact with the upper surface 30 to perform positioning in a direction parallel to the seat surface 28 of the chip 20, and further the seat member 36. The rear end side portion 38a of the convex portion 38 abuts on the inner peripheral portion of the through hole 22, the movement of the seat member 36 on the seat surface 28 is suppressed, and the positioning of the chip 20 in the thickness direction is performed. This completes the fixing of the tip 20 to the tip seat 26 (state of FIG. 6). At this time, the distances D2 and L2 are minimum values. Further, the gap m2 between the tip end side portion 38b of the convex portion 38 and the through hole 22 becomes maximum. The bolt 46 may be tightened in order to more firmly fix the sheet member 36 to the tool body 24. Since the bolt 46 is provided perpendicularly to the lower surface of the seat member 36, the seat member 36 can be firmly fixed onto the seat surface 28 without moving the seat member 36 along the seat surface 28. Therefore, the clamping rigidity of the chip 20 can be further enhanced.

According to the throw-away cutting tool as described above, the positioning accuracy of the tip 20 in the direction parallel to the tip seating surface 28 does not depend on the accuracy of the through hole 22 formed in the tip 20. Since it is determined by the accuracy of the outer shape of the tip 20 and the upper surface 30 of the side wall formed on the tool body 24, which is easier to achieve accuracy than the formation of the cutting edge 22, compared with the conventional throw-away type cutting tool. Position accuracy can be improved. In particular, when the clamp piece 60 is tightened, the spring 44 urges the chip 20 through the sheet member 36 in the direction opposite to the clamp piece tightening direction, so that the force of the spring 44 is resisted. By tightening the clamp piece 60 with the blade, the accuracy of the tip position of the tip 20 can be improved.

When the clamp piece 60 is loosened, the tip 20 moves to the tip side of the tool body together with the sheet member 40 so that the tip 20 can be easily removed. Therefore, the attachment and detachment work of the tip 20 is extremely easy. As a result, it is possible to reduce the time and labor required for mounting the chip and also to shorten the working time, thus improving the working efficiency.

Further, the tip 20 is firmly fixed to the tool body 24, the rigidity of the tip clamp part is improved, and the load resistance is improved, so that it can be used under heavy cutting conditions which could not be used conventionally. Is possible.

In the above embodiment, the cutting tool has been shown as an example of the throw-away type cutting tool, but the present invention is not limited to this, for example, a boring bar or the like, and a chip seat of a chip using a clamp piece. Any cutting tool that can be attached to a throw-away type cutting tool can be used.

Further, the shape of the recess formed in the chip may not penetrate the thickness direction.

[0021]

[Effect of the device]

 As described above, according to the throw-away cutting tool according to the present invention, the side wall of the tip seat or a part thereof serves as a positioning surface on which the side surface of the tip abuts, and the seat surface of the tip seat. Is formed so that the depth of the tip seat gradually decreases toward the tip side of the tool body with respect to the tip clamping direction of the clamp piece. The tool body and the seat are provided with a seat member that gradually decreases toward the tip side, a convex portion that engages with the concave portion of the tip is formed on the upper surface, and a lower surface is slidably formed on the seat surface of the chip seat. Since a biasing means for biasing the sheet member toward the tip of the tool body is provided between the member and the member, it is only necessary to tighten the chip mounted on the sheet member with the clamp piece. Tip , In the thickness direction of the insert pocket in a direction parallel and said chip and fit precisely position-decided. At this time, since the urging means urges the chip through the sheet member in the direction opposite to the clamping direction of the clamp piece, the tip of the chip is tightened against the force of the urging means. The positioning accuracy of is high.

Therefore, according to this throw-away type cutting tool, the tip can be accurately mounted to the tip seat regardless of the accuracy of the recess formed in the tip, and the conventional throw-away type cutting tool is provided. It is possible to improve the accuracy of the position of the cutting edge compared to.

When the clamp pieces are loosely tightened, the tip moves together with the sheet member toward the tip of the tool body and can be easily removed. The time and effort required can be reduced and the work time can be shortened, thus improving work efficiency.

Further, the tip is firmly fixed to the tool body, the rigidity of the tip clamp part is improved, the load resistance is improved, and it can be used under heavy cutting conditions that could not be used conventionally. Becomes

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the line AA of FIG.

FIG. 2 is a plan view showing a throw-away type cutting tool according to an embodiment of the present invention.

FIG. 3 is a side view showing the indexable cutting tool.

FIG. 4 is an explanatory view showing a method of mounting a tip of the indexable cutting tool.

FIG. 5 is an explanatory view showing a method of mounting a tip of the throw-away cutting tool.

FIG. 6 is an explanatory view showing a method for mounting a tip of the throw-away cutting tool.

FIG. 7 is a side sectional view showing a conventional throw-away type cutting tool.

[Explanation of symbols]

 20 chip 22 concave part (chip) 24 tool body 26 chip seat 28 seat surface 34 side wall 36 sheet member 38 convex part (sheet member) 44 biasing means 46 bolt 60 clamp piece

Claims (1)

[Scope of utility model registration request] 1. A throwaway tip having a recessed portion extending in the thickness direction at a substantially central portion is mounted on a tip seat provided on a tool body, and the throwaway tip is provided on the tool body. In a throw-away type cutting tool which is pinched and fixed to the tool body by a piece, a side wall of the tip seat or a part of the side wall is used as a contact surface of a side surface of the throw-away tip,
The seat surface of the tip seat is formed so as to be inclined with respect to the tip clamping direction of the clamp piece in a direction in which the depth of the tip seat gradually decreases toward the tip side of the tool body, the tip seat and the throw-away tip. Between the and, the thickness gradually decreases toward the tip side of the tool body, a convex portion that engages with the concave portion of the throw-away tip is formed on the upper surface, and the lower surface is slidably formed on the seat surface of the tip seat. And a biasing means for biasing the sheet member toward the tip side of the tool body is provided between the tool body and the sheet member. Cutting tools.