JP3850068B2 - Slow away insert and rotary cutting tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a throwaway tip attached to a tool main body or a plurality of throwaway tips and a rotary cutting tool attached with the tips.
[0002]
[Prior art]
There are a vertical clamp method and a horizontal clamp method as a method of attaching the throwaway tip to the rotary cutting tool.
[0003]
As shown in FIG. 16, the vertical clamping method is such that the chip body 1 is attached in the substantially circumferential direction along the outer periphery of the tool body 2, whereas the horizontal clamping method is as shown in FIG. The chip body 1 is inserted in the radial direction of the tool body 2 and attached. As can be seen from a comparison between the two figures, the vertical clamping method has a higher chip strength and heavy cutting because the main cutting force Pb is applied in the thickness Pa direction of the chip body 1 than the horizontal clamping method. However, it has long been recognized in the industry that stable processing with less chipping and the like can be performed.
[0004]
As for the tool body 2 as well, the vertical clamping method is clearer than the horizontal clamping type chip pocket 12a, as shown in FIG. 18 and FIG. Since it can be set as the structure which discharges | emits wa, it can be said that the rigidity of the tool main body 2 is high.
[0005]
In the case of the wedge clamp method, which is a type of a horizontal clamp method that is generally used as shown in FIG. 20, the tightening force by the wedge 13 gives distortion to the entire tool body during chip clamping. In addition, there is a problem that the contact accuracy of the cutting blade is deteriorated. On the other hand, in the case of the saddle type clamp method, as shown in FIG. 16 or FIG. 18, the clamp of the chip body 1 is clamped to the tool body 2 from the outer peripheral side by the screw 14. There is no such thing as generating distortion and reducing accuracy. In addition, in FIGS. 18-20, the code | symbol S is the cutting surrounding surface by the main cutting edge 7 with respect to a workpiece.
[0006]
On the other hand, as shown in FIG. 21, in the conventional vertical clamp system, the mounting surface 4 and the flank 5 of the chip body 1 and the main cutting edges 7 and 7 are basically parallel to each other. In addition, the tip body 1 may be used in a vertical shape along the outer peripheral surface of the tool body 2, and the edge of the flank 5 of the tip body 1 may interfere with the work material. Therefore, the actual clearance angle becomes larger than necessary, which causes a problem that the strength of the cutting edge is lowered and the advantage of the vertical clamping method of the folding angle cannot be utilized.
[0007]
Further, in the conventional vertical clamp system, as shown in FIG. 16, generally, the radial rake angle β is large and negative, so that the cutting resistance is large, which is generally a relatively large diameter. Roughing with face mills and face mills is designed with an emphasis on the use of large horsepower machines, and it has been difficult to apply to small-diameter rotary cutting tools. The improvement of the secondary cutting edge 11 in charge of was left behind.
[0008]
Needless to say, in order to achieve the bottom-up surface processing well, the width and angle of the secondary cutting edge are important.
[0009]
However, as shown in FIG. 22, there is a conventional example in which a chamfer angle α is provided to reduce the cutting resistance of the main cutting edge 7 when the chip body 1 is attached to the tool body 2, but it is ugly to the sub cutting edge 11. There was no horn in the past. Therefore, dissatisfaction remained with respect to the machining of the bottom finish surface of the work material.
[0010]
[Problems to be solved by the invention]
The present invention pays attention to the importance of the clearance angle, and further has a large axial rake angle as much as possible, low cutting resistance, high cutting edge strength, and a throw-away tip capable of processing with a good finished surface and a small diameter. The purpose is to propose a rotary cutting tool that can be manufactured up to.
[0011]
[Means for Solving the Problems]
In order to solve the above problem, according to the invention according to claim 1, the bottom surface of the chip body 1 made of a substantially parallelogram-shaped thick plate is the mounting surface 4 fixed to the mounting seat 3 of the tool body 2, The flank 5 is formed on the convex curved surface 9 whose surface bulges convexly, the left and right sides are scooping surfaces 6 and 6 for cutting the work material, and the scooping surfaces 6 and 6 and the flank 5 The left and right boundary regions are the main cutting edge 7, and a mounting screw hole 8 is provided from the flank 5 to the mounting surface 4 so as to be attached in a substantially circumferential direction along the outer peripheral surface of the tool body 2. In the vertical clamp type throw-away tip, the convex curved surface 9 formed on the flank 5 is formed into a convex curve having the same curvature over the entire area, and both the scooping surfaces 6 and 6 and the left and right sides of the flank 5 are provided. Both main cutting edges 7 formed in the boundary region are inclined so as to cross each other. It is characterized by being formed . Further, by configuring the flank substantially in an R shape, it has been possible to solve the above-mentioned problems related to a chip having a parallel, single flat flank.
[0012]
As described above, the flank 5 facing the main cutting edge 7 is formed into a convex curved surface 9 having the same curvature over the entire area, thereby setting an appropriate flank angle, and at the same time, an axial rake angle and a radial rake angle as large as possible. Furthermore, a good finished surface can be obtained. That is, as will be described later, a throw-away tip that is as close as possible to the characteristics of a known solid end mill can be manufactured.
[0013]
In particular, as described above, the main cutting edges 7 and 7 formed in the left and right boundary regions of the scooping surfaces 6 and 6 and the flank 5 are formed so as to be inclined so as to intersect with each other, so that the axial is as large as possible. A pair of main cutting edges having a rake angle and an optimum clearance angle can be formed, and a throwaway tip with good sharpness can be provided while effectively maintaining the exchange function (FIGS. 2 to 5).
[0014]
The concept behind the invention according to claim 1 will be described. Needless to say, the ideal cutting edge shape is a solid Lind mill T as shown in FIG. The solid end mill T is polished to the maximum axial rake angle (in the case of a solid end mill, it is called the torsion angle, usually 30 ° or more), and the maximum radial rake angle (generally, it is generally referred to as a large angle of 5 ° to About 15 °) and a maximum clearance angle (usually 5 ° to 7 °).
[0015]
Ideally, the configuration of the blade portion Ta of the solid end mill T should be taken out as shown in FIG. 10 and reproduced as it is as the configuration of the throwaway tip. However, the throwaway tip is different from the solid end mill. The axial rake angle is limited to about 10 ° due to constraints such as the tip being independent from the tool body, the tip's unique shape, and the tip's own molding method. It has been devised to suppress the cutting resistance by adding a large scooping angle to the scooping surface of the main body and taking a large radial rake angle, and adopts the blade part of the solid end mill as it is as the structure of the throwaway tip I can't do it.
[0016]
On the other hand, if the throwaway tip is brought as close as possible to the shape of the solid end mill, which is the ideal blade shape, and the economy that is the feature of the throwaway tip method is utilized, the number of main cutting edges of the tip, That is, at least a plurality of exchangeable cutting edges are required.
[0017]
The present inventor has succeeded in overcoming the above-mentioned constraints, and first focused on the basic shape of an ideal solid end mill in terms of cutting. That is,
(1) The solid end mill has a cylindrical shape as shown in FIG.
(2) Make a torsion angle (axial rake angle) in the cylinder (Figs. 9 and 11),
(3) Further, in the solid end mill, an eccentric second angle (R-shaped second surface), which is an ideal flank, is provided for the width corresponding to the flank of the chip body (FIG. 9).
(4) If this R-shaped second surface, that is, the convex curved surface portion is cut and formed into a throwaway tip shape as shown in FIG. 10, a throwaway tip having at least two main cutting edges can be formed. Become.
[0018]
In other words, as shown in FIGS. 11 and 12, the piece 16 (chip) is cut out from the cylindrical body 15 in a size suitable for being attached to the tool body, and this piece 16 (chip) is shown in FIG. 12. Thus, if it is configured to be attached by rotating 5 ° to 7 ° in the circumferential direction so that a clearance angle θ of about 5 ° to 7 ° is attached to the tool body 2, the rotary cutting tool close to an ideal state is obtained. Will be formed.
[0019]
The invention according to claim 1 (FIGS. 1 to 5) is embodied based on the above-described concept.
[0020]
[0022]
In the invention according to claim 2, the convex curved surface 9 formed on the flank 5 is formed of a plurality of stepped surfaces 9 a and 9 b that change stepwise. (FIGS. 13 to 15).
[0023]
According to the third aspect of the invention, as shown in FIGS. 6 and 7, the auxiliary cutting edges 11, 11 are formed in the boundary region between the front and rear end faces 10, 10 of the chip body 1 and the scooping faces 6, 6. The sub-cutting blades 11 and 11 are formed to be continuous with the main cutting blades 7 and 7 and have the structure according to claim 1 or 2.
[0024]
That is, according to the third aspect of the invention, by extending the ridge line of the main cutting blades 7 and 7 having a narrow angle to the auxiliary cutting blades 11 and 11, the auxiliary cutting blades 11 and 11 have an axial rake angle. In addition to θ2, the chip body 1 has a rake angle corresponding to the rake angle θ1, which reduces the cutting resistance at the bottom surface of the work material, improves the sharpness, improves the quality of the finished surface, and further improves the straight surface portion parallel to the bottom surface. By providing the (secondary cutting edge 11), it works as a cutting edge, so that the effect of improving the finished surface roughness is produced.
[0025]
Further, according to the invention according to claim 4 , any one of claims 1 to 3, further comprising a required axial rake angle θ1 (axial rake angle) and a radial rake angle β (radial rake angle) (FIG. 1). The present invention relates to a rotary cutting tool in which the described throwaway tip is attached to a tool body 2 provided with a mounting seat 3 parallel to the axial direction.
[0026]
According to the present invention, the mounting seat 3 (FIG. 8) on the tool body 2 side may be manufactured so as to be parallel to the axial direction.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram for explaining a main part of an embodiment of the present invention .
First, referring to FIGS. 1A and 1B, in the chip body 1 made of a substantially parallelogram-shaped thick plate, the bottom surface surrounded by the points A′B′C′D ′ is the mounting seat 3 of the tool body 2. The surface surrounded by the point ABCD is the flank 5 and the side surface surrounded by the left point ABB′A ′ and the right DCC′D ′ is the scooping surfaces 6 and 6. The AB and DC lines in the left and right boundary areas of the scooping surfaces 6 and 6 and the flank 5 are the main cutting edges 7 and 7, and the mounting hole 8 extends from the flank 5 to the mounting surface 4. The throwaway tip thus formed is characterized in that the flank 5 facing the main cutting edges 7 and 7 is formed as a convex curved surface 9 bulging in a convex shape with the same curvature over the entire area. It is.
[0028]
In an example of the main part of this embodiment, the height is AA ′ = BB ′ = CC ′ = DD ′, and two cutting blades 7 and 7 are formed in parallel, and this is attached. The mounting seat 3 of the tool body 2 naturally has a required clearance angle in the circumferential direction, and any one of the cutting edges 7 faces the cutting circumferential surface S on the mounting seat 3 having the clearance angle in the circumferential direction. By attaching the chip body 1, a gap H for avoiding interference with the work material is formed.
[0029]
In the main part of this embodiment, the convex curved surface 9 formed on the flank 5 as described above has the same radius of curvature from the bending centers OA and OB over the entire area of the main cutting edge 7 (ridge line AB). It is formed in an R shape by r.
[0030]
1 (a) and 1 (b), the clearance angle αAr at the point A at the radius of curvature r and the clearance angle αBr at the point B at the same curvature r are shown in FIG. The clearance angle αAf at point A in the case of a flat flank, which is a technique, and the clearance angle αBf at point B in the case of a flat flank are shown.
[0031]
The clearance angle αAr at the point A of the present invention <the clearance angle αAf at the point A of the prior art
The clearance angle αBr at the point B of the present invention <the clearance angle αBf at the point B of the prior art
Thus, by forming the flank 5 on the convex curved surface 9, it can be seen that the present invention has an effect of reducing the flank angle as compared with the conventional flat flank.
[0033]
As described above, the flank 5 facing the main cutting edge 7 is formed into a convex curved surface 9 having the same curvature over the entire area, thereby setting an appropriate flank angle, and at the same time, an axial rake angle and a radial rake angle as large as possible. Furthermore, a good finished surface can be obtained. That is, as described above, a throw-away tip that is as close as possible to the characteristics of a known solid end mill can be manufactured.
[0034]
2 to 5 show an embodiment of the present invention. In this embodiment , the main cutting edges 7 and 7 formed on the chip body are formed in a crossed state. is there.
[0035]
That is, the heights AA ′ <BB ′, CC ′ <DD ′, AA ′ = CC ′, BB ′ = DD ′, and the main cutting edge 7 (ridge line AB) and the main cutting edge 7 (ridge line CD) opposite to the main cutting edge 7 Are inclined so as to cross each other.
[0036]
As shown in FIG. 8, the two main cutting edges 7 and 7 formed in the left and right boundary regions of the scooping surfaces 6 and 6 and the flank 5 are thus inclined so as to cross each other. When the chip body 1 is attached to the tool body 2, the pair of main cutting edges 7 and 7 having the largest possible rake angle θ1 and the optimum clearance angle can be formed, and the exchange function is effectively maintained. However, it is possible to provide a throwaway chip with a good sharpness.
[0037]
In the production of chips, powder press sintering method or injection molding method is possible, and the chip material sintered in a shape approximate to the final chip body is attached to a jig, and the most suitable by cylindrical polishing molding method The chip body according to the present invention having the arc-shaped flank face can be formed, and it is easy to manufacture a chip which looks difficult at first glance.
[0038]
6 and 7, sub-cutting blades 11 and 11 are formed in a boundary region between the front and rear end surfaces 10 and 10 of the chip body 1 and the scooping surfaces 6 and 6, and the sub-cutting blades 11 and 11 7 shows an embodiment formed continuously with 7,7.
[0039]
That is, as shown in FIG. 7, the part surrounded by the point AA′B′B is cut into the part surrounded by the point EFGH, and the necessary scooping angles θ 2, respectively, are formed on the ridge line AA ′ and the part facing the ridge line AB. By taking θ3, the ridgeline AA ′ is the secondary cutting edge 11, the ridgeline AB is the main cutting edge 7, and the two cutting edges 7 and 11 are formed continuously with each other. By extending the ridge line of the main cutting blades 7 and 7 to the auxiliary cutting blades 11 and 11, the auxiliary cutting blades 11 and 11 have a rake angle corresponding to the rake angle θ1 of the chip body 1 in addition to the axial rake angle θ2. The cutting resistance at the bottom of the work material is reduced, the sharpness is improved, the quality of the finished surface is improved, and a straight part (sub cutting edge 11) parallel to the bottom is provided to serve as a cutting edge. Therefore, the effect of improving the finished surface roughness is born.
[0040]
This arc flank is not necessarily required to cover the entire surface of the main chip flank. As shown in FIG. 13, a minimum width L ₁ including a cutting edge ridge line of the width plus α when worn as shown in FIG. .2 mm or more) is sufficient.
[0041]
Furthermore, the convex curved surface 9 is not limited to an arcuate curved surface, and is formed on stepped surfaces 9a and 9b in which a plurality of planes are formed stepwise as shown in FIGS. It goes without saying that the same effect can be obtained by configuring the flank 5 in the vicinity of an actual clearance angle of 5 ° to 7 °.
[0042]
【The invention's effect】
According to the first aspect of the present invention, the clearance angle of the main cutting edge becomes appropriate, the cutting edge strength is significantly increased, and chipping and chipping are reduced.
[0043]
According to the present invention, since the clearance angle is small and appropriate, the radial rake angle can be increased accordingly, and the cutting edge can be sharpened, so that the cutting resistance can be greatly reduced.
[0044]
Therefore, according to the present invention, the cutting resistance can be greatly reduced, so that it is possible to apply to a small diameter, which has been difficult in the past, and the application field can be expanded.
[0045]
In particular, according to the present invention, since both main cutting edges formed in the right and left boundary regions of the scooping surface and the flank are inclined so as to cross each other, the largest possible rake angle and the optimum flank angle A pair of main cutting edges can be formed, and a slow-away tip with good sharpness can be provided while effectively maintaining the exchange function. In addition, the present invention is applied to the vertical clamping system so that the chip body is attached in the substantially circumferential direction along the outer periphery of the tool body, despite the above-described action. Since the main cutting force is applied in the direction, the chip strength is high, and stable machining with little chipping and the like can be performed even with heavy cutting .
[0046]
According to the present invention , since the convex curved surface formed on the flank of the chip body is formed with the same curvature over the entire area, the chip body can be easily molded and can be manufactured at low cost.
[0047]
According to the second aspect of the present invention, the convex curved surface formed on the flank of the chip body is composed of a plurality of stepped surfaces that change stepwise, and thus is composed of a plurality of flat surfaces that are relatively easy to manufacture. Since it is sufficient to form the convex curved surface, the manufacturing cost can be reduced accordingly.
[0048]
According to the invention of claim 3 , by extending the ridge line of the main cutting edge having a chamfering angle to the sub cutting edge, the sub cutting edge has a scooping surface of the chip body 1 in addition to the axial rake angle. With a chamfered corner, cutting resistance at the bottom surface of the work material is reduced, sharpness is improved, finished surface quality is improved, and a straight part (sub cutting edge) parallel to the bottom surface is provided, so Since it works, the quality of the bottom finish surface can be improved.
[0049]
According to the invention of claim 4, a high-precision throw-away tip and a cutting tool to which the tip is attached can be easily manufactured, and can be provided at low cost.
[Brief description of the drawings]
FIGS. 1A and 1B are diagrams for explaining a main part of an embodiment of a throwaway tip according to the present invention, in which FIG. 1A is a side view and FIG. 1B is a front view.
FIG. 2 shows an embodiment of the present invention, in which (a) is a side view and (B) is a front view.
FIG. 3 is a perspective view of the embodiment shown in FIG.
FIG. 4 is a side view of the same.
FIG. 5 is an end view of the same.
FIG. 6 is a perspective view of a throwaway tip according to another embodiment.
FIG. 7 is a perspective view of the main part.
FIG. 8 is a view showing a state in which the tip according to the embodiment is attached to the tool body.
FIG. 9 is an explanatory diagram for theoretically explaining the production of the throwaway tip according to the present invention.
FIG. 10 is a similar explanatory diagram.
FIG. 11 is an explanatory diagram for theoretical explanation when manufacturing the throwaway tip according to the present invention.
FIG. 12 is a similar explanatory diagram.
FIG. 13 is a perspective view of another embodiment of the slowway tip according to the present invention.
FIG. 14 is an end view showing another embodiment.
FIG. 15 is a perspective view of the same embodiment.
FIG. 16 is a diagram showing a state of use of the prior art.
FIG. 17 is a diagram showing a state of use of the prior art.
FIG. 18 is a diagram showing a state of use of the prior art.
FIG. 19 is a diagram showing a state of use of the prior art.
FIG. 20 is a diagram showing a state of use of the prior art.
FIG. 21 shows a perspective view of a conventional slow eye tip.
FIG. 22 is a view showing a state in which the throw-away tip is attached to the tool body.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tip main body 2 Tool main body 3 Mounting seat 4 Mounting surface 5 Relief surface 6 Scuffing surface 7 Main cutting edge 8 Screw hole 9 Convex curved surface 10 End surface 11 Sub cutting edge

Claims (4)

The bottom surface of the chip body made of a substantially parallelogram-shaped thick plate is a mounting surface that is fixed to the mounting seat of the tool body, and is a relief surface that is formed as a convex curved surface whose surface bulges in a convex shape. Is a scooping surface for cutting the work material, the left and right boundary areas of the scooping surface and the flank are the main cutting edges, and the mounting screw holes are penetrating from the flank to the mounting surface , In the vertical clamp type throw-away tip attached in the substantially circumferential direction along the outer peripheral surface of the tool body, the convex curved surface formed on the flank is formed into a convex curved shape with the same curvature over the entire area, A throwaway tip characterized in that the two main cutting edges formed in the left and right boundary regions of the scooping surface and the flank surface are formed to be inclined so as to cross each other .   The throwaway tip according to claim 1, wherein the convex curved surface formed on the flank comprises a plurality of stepped surfaces that change stepwise.   3. The throwaway tip according to claim 1, wherein a secondary cutting edge is formed in a boundary region between the front and rear end faces of the chip body and the scooping surface, and the secondary cutting edge is formed continuously with the main cutting edge.   The throwaway tip according to any one of claims 1 to 3, comprising a required axial rake angle (axial rake angle) and a radial rake angle (radial rake angle), and a mounting seat parallel to the axial direction. A rotary cutting tool attached to the tool body.

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