JP2005118965A - Insert and edge replaceable rotary tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insert shape installed in an edge replaceable rotary tool for further improving processing efficiency; and the edge replaceable rotary tool attached with this insert shape. <P>SOLUTION: This insert is formed in a substantially parallelogram plate shape having a central installation hole. Among four sides for forming the insert, two sides existing in a symmetrical position are a straight line shape, and two sides existing in the other symmetrical position are composed of a circular arc part and a straight line part continuing with the circular arc part. When a distance of the two sides existing in the symmetrical position is set to (w), a distance of the two sides existing in the other symmetrical position is set to (g), the thickness of the insert is set to (t), and a diameter of the central installation hole is set to P, the cross-sectional area A composed of (w, t and P) of the insert is set to 5 mm<SP>2</SP>or more, the cross-sectional area B composed of (g, t and P) of the insert is set to 14 mm<SP>2</SP>or more, and the ratio B/A of the cross-sectional area is set to 1.3 or more. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an insert having a substantially parallelogram flat plate shape and a blade-tip-exchange-type rotary tool equipped with the insert, and particularly to an insert used for reducing the diameter of a blade-tip-exchange-type rotary tool used for high-feed machining.

  Patent Document 1 discloses a blade-tip-exchangeable rotary tool used for high-feed machining. The insert described in Patent Document 1 has a substantially square shape with a pin hole, and has a main cutting edge and a linear inner peripheral cutting edge that are composed of an arc portion and a straight portion connected to the arc portion, and can perform high-feed cutting. It is said. However, in recent years, it has been required to further improve the processing efficiency. As one means for that, it is conceivable to increase the number of inserts to be attached to the blade-tip-replaceable rotary tool under the same tool diameter.

Japanese Patent No. 3317490

  The present invention solves the problem related to the strength of the insert, which is a problem when increasing the number of inserts to be mounted on a high-feeding blade-tip-replaceable rotary tool, and is mounted on the blade-tip-replaceable rotary tool for further processing. An object of the present invention is to provide an insert shape capable of improving the efficiency and a blade-exchangeable rotary tool equipped with the insert shape.

The present invention is an insert having a substantially parallelogram flat plate shape having a central mounting hole, and of the four sides forming the insert, two sides at symmetrical positions are straight and other symmetrical The two sides at the position are composed of an arc portion and a straight line portion connected to the arc portion, the distance between the two sides at the symmetrical position is w, the distance between the two sides at the other symmetrical positions is g, and the insert Where the thickness of the insert is t and the diameter of the central mounting hole is P, the cross-sectional area A of w, t and P of the insert is 5 mm ² or more, and the cross-sectional area B of g, t and P of the insert is The insert is 14 mm ² or more and has a cross-sectional area ratio B / A of 1.3 or more. By adopting this configuration, it is possible to increase the number of inserts to be mounted on a high-feed-blade replaceable rotary tool for the same tool diameter, and even when the insert size is reduced, the strength The problem concerning the surface can be solved. And it becomes possible to provide the blade-tip-exchange-type rotary tool that further improves the processing efficiency. The high feed referred to here is a contour engraving process, a low cut amount, and the feed amount per blade is about 0.6 to 3.5 mm for S50C steel cutting and about 0.8 to 4 mm for cast iron cutting. Say things.

  Further, in the insert of the present invention, the w is 5 ≦ w ≦ 11, and the high-feeding edge-changing rotary tool equipped with the insert is such that the blade-tip-changing rotary tool diameter D is 13 ≦ D ≦ 63. Yes, the number of inserts is 2 or more and 10 or less.

  The high-feed-blade replaceable rotary tool equipped with the insert of the present invention can increase the number of inserts by 2 to 2.5 times at the same tool diameter, and can dramatically improve the cutting efficiency.

  As one means for improving the machining efficiency under the blade-exchangeable rotary tool having the same tool diameter, it is conceivable to increase the number of inserts to be attached to the tool. When increasing the number of inserts installed, there is a limit to the number of possible increases when using inserts of conventional dimensions. This is because when the thickness of the back metal that fixes and supports the insert becomes thinner than a predetermined dimension, there arises a problem that the strength of the tool body is lowered. Therefore, it is conceivable to use an insert with a smaller size. However, with an insert with a smaller size, it becomes easy to cause breakage due to insufficient strength of the insert, starting from a heat crack generated during processing. This phenomenon is particularly likely to occur during engraving. Therefore, it is necessary to take measures against these points in order to expand the use of small-sized inserts. That is, in order to increase the number of inserts using small size inserts, it is necessary to solve the technical problem of improving the strength of the insert itself while maintaining the strength of the tool body.

1 is a front view of an insert example of the present invention, FIG. 2 is a sectional view taken along line aa in FIG. 1, and FIG. 3 is a sectional view taken along line bb in FIG. The insert 2 of the present invention has a substantially parallelogram flat plate shape, and among the four sides, two sides 5a and 5b at symmetrical positions are linear and two sides 6a and 6b at other symmetrical positions. Consists of an arc portion 7 and a straight line portion 8 connected to the arc portion. Also, the distance between the two sides 5a and 5b at the symmetrical positions is w, the distance between the two sides 6a and 6b at the other symmetrical positions is g, the thickness t of the insert, and the circle diameter of the central mounting hole is P. The cross-sectional area A composed of w, t and P is 5 mm ² or more, the cross-sectional area B composed of g, t and P of the insert is 14 mm ² or more, and the ratio of the cross-sectional areas is B / A ≧ It is an insert characterized by being 1.3. The cross-sectional area A is a cross-sectional area along a line aa that passes through the center of the circle of the center mounting hole of the insert and is perpendicular to the sides 5a and 5b. The cross-sectional area B is a cross-sectional area in a direction orthogonal to the cross-sectional area A, and passes through the center of the circle of the center mounting hole of the insert, and is a cross-sectional area at line bb. By A can not be secured pin hole diameter for passing a sufficient size of the screw to secure the insert to the tool body is less than 5 mm ^2, since being damaged by screws loosened, A is 5 mm ² or more is there. If B is less than 14 mm ² , the insert may be damaged in the engraving process. Therefore, in order to ensure the strength of the insert itself, B is 14 mm ² or more. When B / A is less than 1.3, the balance of both cross-sectional areas is improper and the insert strength decreases, and there is a problem that sufficient strength to withstand high feed cutting cannot be secured. FIG. 4 is a view showing an example of the blade-tip-exchangeable rotary tool of the present invention equipped with the insert of the present invention. The insert 2 is mounted on the tool body 3 so that the cutting angle κ of the main cutting edge 7 in the blade-tip-exchange-type rotary tool is 3 degrees or more and 40 degrees or less. The cutting angle κ is an angle formed by a tangent line at the lowest point 13 of the tool cutting edge and a straight line connecting the lowest point 13 and the outermost point 14 of the tool. In the insert of the present invention, w (mm) is 5 ≦ w ≦ 11. If w is less than 5 mm, the screw diameter to be fixed must be reduced, so that there is a disadvantage that the screw is likely to break due to insufficient strength of the screw itself. Since there is an inconvenience that it cannot be increased, w is set to 5 mm or more and 11 mm or less. The tool diameter D of the blade-tip-exchangeable rotary tool of the present invention is 13 to 63 mm. When D is less than 13 mm, there is an inconvenience that the number of inserts cannot be two or more. On the other hand, when D is larger than 63 mm, the insert is small, so there is an inconvenience that it is easily damaged due to insufficient strength. And The blade-tip-exchangeable rotary tool of the present invention is mounted with 2 to 10 inserts. When the number of inserts is 1 blade, machining efficiency cannot be achieved and the tool life is also 1 blade, so there is an inconvenience of short life. On the other hand, when it is over 10 blades, chatter occurs at deep parts and corners during cutting. Since there is an inconvenience that vibration is likely to occur, the number of inserts is set to 2 or more and 10 or less.

  FIG. 5 shows a diagram representing the circumferential space necessary for mounting one insert in angle. While maintaining the strength of the tool body using FIG. 5, the relationship between the number of inserts that can be mounted and the size of the inserts is to ensure the angle θ1 for forming the tip pocket P portion and the strength of the back metal M portion. The angle θ2 for obtaining the necessary thickness h can be expressed by Equation 1 and Equation 2.

here,
R: Tool body radius (mm)
w: Distance between two sides at symmetrical positions (insert width) (mm)
t: Insert thickness (mm)
h: Back metal thickness (mm)
.

  The number of inserts that can be mounted according to Equations (1) and (2) can be obtained by dividing the circumferential angle of 360 degrees by the added value of θ1 and θ2, and truncating the decimal part. The strength of the tool body is not a problem as long as the ratio h / t between the back metal thickness h and the insert thickness t is greater than or equal to a predetermined coefficient α in consideration of factors such as material and diameter. Here, α is a numerical value obtained empirically, and in the calculation of θ2, h = α × t.

  FIG. 6 is a graph showing the relationship between the tool diameter and the number of attached inserts. The relationship between the tool body diameter D calculated by the above equation and the number of inserts is shown using the insert width w as a parameter. From FIG. 6, it was possible to increase the number of inserts while maintaining the tool strength in the blade-tip replaceable rotary tool. In particular, if an insert with w of 6.4 mm is mounted, the number of blades is doubled when the tool diameter is 30, 32, or 50 mm, and the machining efficiency can be doubled. FIG. 7 is a view showing an example of forming a chip pocket in the insert mounting portion. In order to further increase the number of inserts, the chip pocket forming angle θ1 may be reduced. As shown by the dotted line in FIG. 7, the pocket low bottom portion is formed with an angle from the middle, and by applying a nuisance process as shown by the solid line, θ′1 <θ1 can be established. . Thereby, for example, when w is 6.4 mm, the number of inserts can be increased by 1 to 2 from the calculated value. Depending on the application of the rotary tool, it may be desirable to increase the insert size. In such a case, it is preferable to design a tool body that can be worn with a w of 7.9 mm or 10 mm, and to select and use it appropriately. The insert evaluated above is an insert having a substantially rectangular flat plate shape having a central mounting hole, but can also be applied to an insert having no central mounting hole. Moreover, although the insert of this invention is a thing of the range of 5-11 mm, it can be applied also to a large sized insert.

Table 1 shows the results of producing inserts and blade-exchangeable rotary tools of the present invention and comparative examples, and evaluating them by a cutting test. FIG. 8 shows the evaluation results in relation to the cross-sectional area A and the cross-sectional area B. As shown in FIG. 9, the cutting test was performed by engraving shoulder cutting with a constant depth and width, and a tool body with a D of 25 mm was used and the number of blades was one. The evaluation method was performed by observing the state of the cutting edge when the cutting time was 60 minutes, that is, when the cutting distance reached 138 m. The cutting conditions are shown below.
(Cutting conditions)
Machining method: shoulder shaving, down cut Work material: S50C (HB220)
Cutting speed: 180 m / min
Spindle speed: 2292 rpm / min
Table feed rate: 2292 mm / min
Feed per blade: 1mm / blade Cutting depth: 1mm
Cutting width: 10mm

From Table 1, as a result of observing the state of the cutting edge when the cutting distance reached 138 m, no abnormality was found in the inserts of Examples 1 to 4 of the present invention. In Comparative Examples 5, 6, and 7, the insert was damaged before the cutting distance reached 138 m, and the cutting test was interrupted. Prior art examples 8 and 9 showed no abnormalities in the cutting ability such as the strength and life of the insert, and showed stable normal wear. However, the number of inserts cannot be increased when using a blade-exchangeable rotary tool. FIG. 8 is plotted with the cross-sectional area A on the vertical axis and the cross-sectional area B on the horizontal axis for Examples 1 to 4, Comparative Examples 5 to 7 and Conventional Examples 8 and 9 of the present invention. In the present invention examples 1 to 4, the strength of the insert is improved because A is 5 mm ² or more, B is 14 mm ² or more, and B / A is within a range surrounded by a dotted line of 1.3 or more. This is because the insert of the present invention increases the cross-sectional area B in the rotational axis direction of the insert and properly balances the cross-sectional area A for the purpose of preventing heat cracks from being damaged. This is a set effect. It is confirmed that the insert of the present invention has high strength, can prevent cracking due to heat cracks, can perform highly reliable processing, and can be mounted on a cutting edge exchangeable cutting tool to increase cutting efficiency. did it.

FIG. 1 shows an example of an insert according to the present invention. FIG. 2 is a sectional view taken along line aa in FIG. FIG. 3 is a sectional view taken along line bb of FIG. FIG. 4 shows an example of the blade-exchangeable rotary tool of the present invention. FIG. 5 shows the mounting relationship of the insert to the tool body. FIG. 6 shows the relationship between the tool diameter and the number of inserts. FIG. 7 shows an example of the insert attachment portion and chip pocket formation. FIG. 8 shows the evaluation results of the insert. FIG. 9 shows a schematic diagram of a cutting test processing method.

Explanation of symbols

1: Cutting edge-exchangeable rotary tool of the present invention 2: Insert of the present invention 3: Rotary tool main body 4, 14 of the present invention: Circle center of the central mounting hole 5: Side of the straight portion of the insert 6: Arc portion of the insert and a straight line Sides 7 and 17 consisting of parts: Main cutting edge 8, 18: Inner peripheral cutting edge 9, 19: Outer peripheral cutting edge 11: Conventional high feed throwaway rotary tool 12: Conventional insert 13: Tool cutting edge Bottom point 14: Tool outermost point A: Cross-sectional area B: Cross-sectional area w: Distance between two sides at symmetrical positions (insert width)
g: Distance between two sides at other symmetrical positions (insert height)
t: Insert thickness κ: Cutting angle of main cutting edge D: Tool diameter

Claims (4)

An insert having a substantially parallelogram flat plate shape having a central mounting hole, and of the four sides forming the insert, two sides at a symmetric position are straight and two at another symmetric position. The side is composed of an arc part and a straight line part connected to the arc part, the distance between the two sides at the symmetrical position is w, the distance between the two sides at the other symmetrical position is g, and the thickness of the insert is t, where the diameter of the central mounting hole is P, the cross-sectional area A of w, t and P of the insert is 5 mm ² or more, and the cross-sectional area B of g, t and P of the insert is 14 mm ² or more. An insert having a sectional area ratio B / A of 1.3 or more. The insert according to claim 1, wherein w is 5 ≦ w ≦ 11. A high-feed-blade replaceable rotary tool equipped with the insert according to claim 1 or 2, wherein the blade-exchangeable rotary tool diameter D satisfies 13≤D≤63. . The blade-tip replaceable rotary tool according to claim 3, wherein the insert is mounted in the range of 2 to 10 inclusive.

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