JP3694402B2 - Throw-away insert for inner diameter processing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a throw-away tip for inner diameter processing, and more specifically, relates to a throw-away tip for inner diameter processing (hereinafter also referred to as a throw-away tip or simply a tip) used for inner diameter (inner peripheral surface) processing such as boring. .
[0002]
[Prior art]
Conventionally, a bite or a boring bar (hereinafter also referred to as a bar) is used for inner diameter processing such as boring, but these are roughly classified into a solid type and a throw-away type. The solid type has a high degree of freedom in the size of the cutting edge because the blade is formed by so-called sharpening (blade formation) by grinding or polishing a steel material (such as machine tool steel). Even a cutting blade used for machining a small inner diameter of about 3 to 5 mm can be manufactured relatively easily. However, since the cutting edge is formed by sharpening, the disadvantage is that the cost increases. Further, in the formation of the cutting edge by such sharpening, for example, it is not easy to form a convex (raised) chip breaker, and there is a difficulty in improving chip disposal (discharge). Further, such a solid type has a drawback that the cutting edge position is likely to be misaligned when exchanging the cutting tool or the bar, so that it takes time to set up the tool.
[0003]
On the other hand, throw-away types are usually made of ultra-hard tool materials such as cemented carbide and can be manufactured by press-molding and sintering the raw material powder, including the shape of the chip breaker. Can be manufactured at a relatively low cost. And it is clamped (fixed) to the tip seat of a shank or bar with a tip seat (pocket) for tip attachment at the tip, and the cutting edge position is not easily misaligned during tip replacement, and the work is also easy. .
[0004]
[Problems to be solved by the invention]
However, with a bite or boring bar using such a throw-away tip, it is usually difficult to process an inner diameter of less than φ5 mm. This is because, for example, in order to perform inner diameter processing to a certain extent, such as boring, the processing cannot be performed unless a chip to be used enters the inner diameter. In this case, if the tip is of a screw clamp type, considering the diameter of the through hole for the screw clamp and the required thickness of the peripheral edge, it is difficult to make the maximum width of the rake face of the tip less than 5 mm. This is because of this. That is, if it is less than this, the screw diameter used for the clamp becomes too small, and the strength of the cutting tool becomes insufficient, such as a clamp having an appropriate strength cannot be obtained. Further, in the clamp-on method in which the chip is sandwiched (or pulled) by the clamp piece, about φ10 mm is set as the minimum limit of the inner diameter processing due to the presence of the clamp piece. Therefore, in the past, when processing an inner diameter of less than φ5 mm, it was a fact that a solid type had to be used.
[0005]
The present invention has been made in view of the above points, and an object of the present invention is to provide a throw-away tip that enables machining of an inner diameter of less than φ5 mm, which has been difficult with a conventional throw-away tip. There is.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, the inner diameter machining throw-away tip of the present invention includes a clamping part and at least one protruding part integrally protruding from the clamping part. A cutting blade is provided on one side in the vicinity ,
When the throw-away tip itself clamps the clamping part to a bite shank or a boring bar and is used for machining the inner diameter of the workpiece, only the protruding portion enters the workpiece and the inner diameter of the workpiece is machined by the cutting edge. It is that it is formed . Here, the clamping part is a part for clamping the throw-away tip for inner diameter machining to a shank or a boring bar, and a piece receiving part for clamping with a screw clamp through-hole or a clamp piece The part provided with the part.
[0007]
In the present invention, as described above, the cutting edge (blade edge) responsible for the inner diameter processing, that is, the cutting edge that enters into the inner diameter of the workpiece is integrated with the clamp part, but at the tip of the protruding portion protruding from it or in the vicinity thereof. It is provided on one side . When the throw-away tip itself clamps the clamping part to a bite shank or a boring bar and is used for machining the inner diameter of the workpiece, only the protruding portion enters the workpiece and the cutting edge cuts the inner diameter of the workpiece. It is formed so that it can be processed. Therefore , the protruding portion with the cutting edge can be formed in a thickness that falls within a desired small-diameter machining inner diameter without considering clamping. In other words, by setting the thickness (width and thickness) of the protrusion according to the inner diameter of the object to be processed, the diameter of the protrusion depends on the protrusion length of the protrusion with the cutting blade provided on one side thereof. Inner diameter machining such as boring of φ2 to less than 5 mm (hereinafter also referred to as small diameter) can be performed.
[0008]
In addition, since it is not necessary to consider that the part for clamping enters into the inner diameter in the inner diameter processing, it can be formed in a size necessary for clamping regardless of this, and the clamp strength may be a problem. Absent. That is, even when a through-hole for a screw clamp is provided, it is not necessary to make it smaller than that of a chip having a size of about □ 8 mm, for example. Just keep it. Therefore, by forming a clamping part so that it can be clamped to the tip seat in the conventional throw-away tool for inner diameter processing, it can be clamped in the same manner as in the past and used for small diameter inner diameter processing.
[0009]
In addition, the throw-away tip for inner diameter processing according to the present invention can be formed of a super hard tool material such as cemented carbide, cermet, ceramic, etc., as in the past. That is, since the raw material powder can be formed by press molding, sintering or firing, a chip having an appropriate three-dimensional shape consisting of a convex shape, a concave shape, or a combination thereof on the rake face of the cutting edge, like the conventional one. Breakers can be formed without problems. Thus, it is possible to provide a throw-away tip for inner diameter processing capable of processing an inner diameter with a small diameter without impairing chip disposal.
[0010]
The clamping part is not particularly limited as long as it can be clamped without any hindrance to the clamping strength. Therefore, the planar shape or the like may be arbitrary, but as described above, a shank that can clamp a conventional throw away tip, In order to be able to use a bar, it is preferable to form a plate with a substantially polygonal shape such as a square or a rectangle similar to the planar shape of a conventional chip. In addition, the clamp to the shank or bar may be either a clamp-on method or a screwing method, but the screwing method is preferable from the viewpoint of the simplicity of the structure, and therefore penetrates the clamping part in the thickness direction. It is preferable that a through hole for a screw clamp is provided. In the above means, if there are a plurality of protrusions provided with cutting edges, a plurality of cutting edges can be provided in one chip. In this case, the protrusions are provided point-symmetrically when viewed from the rake face side. Good.
[0011]
Furthermore, in the present invention, the length of the protrusion (projection amount) determines the depth of the boring, but this length is so thick that the protrusion does not bend or chatter. It may be set in consideration of (width and thickness). If the protruding amount is large, it forms a rod shape, and if it is short, it forms a convex portion. In addition, what is necessary is just to provide the chip breaker which makes a convex shape or a concave shape in the rake face of the said cutting blade as needed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Now, an embodiment of such an internal diameter machining throw-away tip will be described in detail with reference to FIGS. In the figure, reference numeral 1 denotes a throw-away tip for inner diameter processing of this example, which is made of, for example, a cemented carbide and has a substantially rectangular plate shape having two sides of 12 mm, 8 mm, and a thickness of 2.38 mm. Along the one side, there is provided a rod-like projecting portion 3 projecting a predetermined length L with a fixed width W (for example, 3.5 mm) for a minimum machining inner diameter, for example, φ4 mm. However, the shape or the cross-sectional shape seen from the tip surface 3a side (see arrow A in FIG. 1) of the projecting portion 3 is a substantially semicircular shape with the rake face 4 side as a string. In this example, it is flush with the main surface 5 of the clamping part 2. In addition, the radius of the cross section of the protrusion part 3 is set smaller than the plate | board thickness of the site | part 2 for a clamp, for example, is 1.5 mm. A boring edge (cutting edge) 6 is formed in a V-shape and slightly protrudes at one end of the protrusion 3 or in the vicinity thereof. The clamping part 2 is provided with a screw-clamping through-hole 7 penetrating in the thickness direction, and a tapered surface 8 is formed with the peripheral edge on the side of the rake face 4 being scattered. The through hole 7 has a diameter of 4.6 mm so that a screw (for example, M4) having an inner diameter sufficient for clamping can be inserted.
[0013]
On the other hand, such a chip 1 is used by being clamped to a tip seat 22 at the end of a square shank (hereinafter also referred to as a square shank) 21 shown in FIGS. The square shank 21 is suitable for being used for inner diameter processing by being fixed to a comb blade type turret in an automatic lathe that supports the end of a workpiece with a guide bush, and has a relatively small outer diameter (for example, It is used for machining inner diameters of several mm on round bars (workpieces) of φ10 mm or less. That is, the corner shank 21 is provided with an offset portion 23 at the tip thereof, and a chip seat 22 (pocket) with a screw hole 24 that is substantially the same shape in plan view as that for clamping the clamping portion 2 of the tip 1 is recessed in the offset portion 23. Has been established. Then, as shown in FIG. 4, the chip 1 of this example is placed on the chip seat 22 and clamped with a set screw 25 to form a boring tool, which is a comb-type tool post (see FIG. 4). The workpiece (indicated by a two-dot chain line in FIG. 4) 30 is bored while being fixed to the not shown. In this example, the protrusion T of the cutting blade 6 from the reference plane K of the shank 21 is set to be within +1 mm and within −2 mm, and traverses in the coaxial direction while rotating around the rotation axis G. The opening end of the work 30 is inserted into a pocket (recessed space) H formed on the side of the cutting edge 6 of the protrusion 3.
[0014]
In such processing, the throwing tip 1 for inner diameter processing of the present example has a wide clamping portion 2 like a normal size tip so that sufficient clamping strength can be exhibited irrespective of the protrusion 3. Therefore, there is no problem (insufficiency) in clamping strength. And in boring, it can cut by putting only the protrusion part 3 with a narrow width | variety into the process internal diameter, without putting the clamped site | part 2 for clamping into the process internal diameter (inside a lower hole) of the workpiece | work 30. Therefore, in this example, boring with a small diameter of about 4 mm is possible up to the depth of the length L of the protruding portion 3.
[0015]
In addition, in this example, since the shape and cross-sectional shape seen from the front end surface 3a of the protrusion part 3 were made into a substantially semicircle, the intensity | strength of the protrusion part 3 can be hold | maintained effectively, without having a bad influence on chip disposal property. . However, as shown in FIG. 5, the cross-sectional shape of the projecting portion is a ¼ circular section over the entire length L of the projecting portion 3 in consideration of its strength and chip disposal, or as shown in FIG. When the boring depth is shallow and there is no problem with chip disposal like the protruding portion 3, the shape may be appropriately set such as a substantially circular cross section except for the rake face 4 (near the cutting edge 6). 5 and 6 have the same reference numerals as those in FIG. 1.
[0016]
Further, in the chip 1 provided with the cutting blade 6 used for boring as shown in FIG. 1, the rake face 4 is required depending on the cutting conditions (such as chip disposal) as shown in FIGS. If it does, you may provide the chip breaker 4a which makes convex shape (bump shape), or the chip breaker 4b which makes concave shape. The length of the protruding portion 3 of such a chip may be set according to the boring depth, and the width, thickness, etc. may be set appropriately according to the machining inner diameter (boring diameter). That's fine. Note that the length of the protruding portion may be set as appropriate within a range in which no deflection or chatter occurs in consideration of the thickness, cross-sectional shape, and workpiece material.
[0017]
In the above embodiment, the chip 1 having the cutting edge 6 for boring is described, but the shape of the cutting edge may be appropriately set according to the type of inner diameter processing. For example, when used for inner diameter grooving, the shape of the cutting edge 6 may be a (planar) shape that matches the groove shape as shown in FIG. What is necessary is just to make it the (planar) shape of the cutting blade 6 matched with the thread as shown. Further, when used for the step processing of the inner diameter, the shape of the cutting edge 6 as shown in FIG. In addition, the same code | symbol is attached | subjected to the part same as that of FIG. 1 in the chip | tip 1 of FIGS.
[0018]
Moreover, although the thing with one protrusion part (protrusion part with a cutting blade) which provided the cutting blade in all the said forms was illustrated, in this invention, this number is not limited to this but can also provide two or more. FIG. 12 shows an example of this. FIG. 12 shows a chip 11 in which two protrusions 3 with cutting edges 6 are provided point-symmetrically in the same manner as in FIG. . In such a case, a relief (concave portion) 26 is formed on the tip seat 22 of the shank 21 so that the protrusion 3 with the cutting edge 6 that is not used is accommodated.
[0019]
The shank that clamps the tip may be an appropriate one according to the mounting conditions on the tool post, etc., and is naturally not limited to those exemplified in the above embodiment, and is shown in FIG. A shank 31 or the like for peripheral turning can also be used, and the tip 1 can of course be used with its protruding portion 3 protruding along the longitudinal direction of the shank 31.
[0020]
And in the said form, since the clamp to the shank of the chip | tip 1 is a screwing thing, it was with the through-hole 7. However, although this is not shown in figure, when the clamp to a shank is a clamp-on system by a clamp piece In this case, a piece receiving portion (concave portion) corresponding to the clamp piece may be provided on the main surface of the clamping portion without a hole or, if necessary. And although the planar shape of the site | part for a clamp was made into the substantially rectangular shape in the said form, it can be set as appropriate shapes, such as a square. Furthermore, in the said form, although the protrusion part was made to protrude along the side surface (side) of the site | part for a clamp, it is clear that the position (part) to make it protrude is not limited to this. That is, it is apparent that the inner diameter machining throw-away tip according to the present invention can be put into practical use by appropriately changing the shape from that of the above-described form within a range not departing from the gist thereof.
[0021]
In addition, the throwaway tip 1 for inner diameter machining of the present invention described above can be used for inner diameter machining even if it is clamped on a boring bar used on a lathe core or a boring machine. can do. That is, when used as a boring bar, it is clear that the same effect as in the above embodiment is obtained.
[0022]
14 and 15 show an example of such a case. In the figure, instead of the square bite shank, the chip 1 is clamped in the same manner as described above on a rectangular chip seat 22 formed at the tip of a bar 41 having a substantially circular cross section. Since there is no difference between the tip 1 and the operation part except that the protruding part 3 protruding from the clamping part 2 is changed to protrude along one side of the opposite side, the same part has Only the same reference numerals are used.
[0023]
In this case, if necessary, a chip breaker may be provided in the same manner as described above, or an appropriate cutting edge shape may be formed according to processing. Moreover, what is necessary is just to design suitably according to process conditions in the implementation, such as making it possible to use multiple blades.
[0024]
【The invention's effect】
As is clear from the above description, the inner diameter machining throw-away tip according to the present invention has a small diameter of less than φ5 mm, which is difficult to machine with a conventional throw-away tip, without causing a decrease in clamp strength. Inner diameter machining can be realized. In addition, a clamping part is formed so that it can be clamped to a conventional throw-away tool for inner diameter processing or a chip seat in a boring bar, and a protrusion with a cutting edge is provided so as to be suitable for required inner diameter processing of a small diameter. By forming it, it is possible to process a desired small-diameter inner diameter with a conventional shank or boring bar.
[Brief description of the drawings]
FIG. 1 is a perspective view of an embodiment of a throwaway tip for inner diameter processing according to the present invention.
2 is a partially broken sectional view of the throw-away tip in FIG. 1 as viewed from the direction of arrow A. FIG.
FIG. 3 is a perspective view of an example of a shank that clamps the chip of FIG. 1;
4 is a plan view of a principal part in which the chip of FIG. 1 is clamped to the shank of FIG. 3;
FIG. 5 is a perspective view of another embodiment of the throw-away tip according to the present invention.
FIG. 6 is a perspective view of another embodiment of the throw-away tip according to the present invention.
FIG. 7 is a perspective view of the main part of another embodiment of the throw-away tip according to the present invention.
FIG. 8 is a perspective view of the main part of another embodiment of the throw-away tip according to the present invention.
FIG. 9 is a plan view of another embodiment of the throw-away tip according to the present invention.
FIG. 10 is a plan view of another embodiment of the throw-away tip according to the present invention.
FIG. 11 is a plan view of another embodiment of the throw-away tip according to the present invention.
FIG. 12 is a plan view of another embodiment of the throw-away tip according to the present invention.
13 is a plan view in which the throw-away tip of FIG. 1 is clamped to another shank.
FIG. 14 is a plan view of another embodiment of the throw-away tip according to the present invention.
15 is a view of the throw-away tip in FIG. 14 as viewed from the direction of arrow A. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Throw-away tip for internal diameter processing 2 Clamping part 3 Protruding part 6 Cutting edge 7 Through-hole 21, 31, 41 for screw clamp

Claims (3)

A clamping part and at least one protruding part integrally projecting from the clamping part, provided with a cutting edge at the tip of the protruding part or one of the vicinity thereof ,
When the throw-away tip itself clamps the clamping part to a bite shank or a boring bar and is used for machining the inner diameter of the workpiece, only the protruding portion enters the workpiece and the inner diameter of the workpiece is machined by the cutting edge. A throw-away tip for inner diameter processing characterized by being formed .  The throw-away tip for inner diameter processing according to claim 1, wherein the clamping part has a substantially polygonal plate shape.  The throwaway tip for inner diameter processing according to claim 1 or 2, wherein a through-hole for a screw clamp that penetrates in the thickness direction is provided in the clamp portion.

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