JP2765778B2 - Cutting tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft-shaped shank comprising a mounting portion to be fitted and mounted in a tool holding hole of a rotary spindle of a machine tool and a cutting blade holding portion extending from the mounting portion. The cutting tool is formed as a structural element with the cutting blade attached to the cutting blade holder of the shank, and relates to a cutting tool that performs cutting of the work surface, especially when the cutting tool is mounted on a main shaft of a machine tool.
Unlike a cutting tool that is cut in the axial direction of the mounting portion sequentially to cut the upper surface of the work, a predetermined traveling direction while gradually receiving at least a cutting feed in a lateral direction or a side direction with respect to the axial center of the mounting portion. At the same time as the cutting action
The structure of the cutting tool can be changed freely by rotating around the rotation axis (hereinafter referred to as C-axis rotation), and it receives the cutting reaction force during the cutting action to cut the work surface of the work. In addition to preventing the cutting blade from damaging the machined work surface, the slit that forms a fulcrum for elastic deformation is also used to prevent inconvenience such as galling and biting in the cutting direction. The present invention relates to a hale bite type cutting tool having a structure capable of smoothly performing a planing process on a work surface from a rough cutting process to a fine finish cutting process by providing the cutting tool in the above-described cutting direction.

[0002]

2. Description of the Related Art It has been well known that a hale bite is used as a cutting tool in a machine tool, especially a machine tool such as a lathe, a planing machine, and a shaping machine, for cutting a work surface. Types such as a hale finish bite, a hale threaded bite, and the like are mainly known. This type of hail bite is a cutting tool characterized by having a U-shaped bent spring action portion in the tool tip region near the cutting blade to prevent galling or biting during the cutting operation. With this type of conventional hail bite, the posture of the work with respect to the work is not changed during processing, and processing of desired dimensions can be performed if the positional relationship between the cutting edge of the hail bite and the work is determined before processing.

On the other hand, recently, there has been a demand for performing a cutting process such as a grooving process on a work having a planar processing surface by a milling machine tool. For example, in mold processing, etc., simply
There is also a demand for precisely processing not only straight grooves but also grooves along closed curves. Conventionally, in such a curved groove, processing using an end mill as a cutting tool is generally performed.
In this end milling method, since the cutting is performed while the tool itself has a rotation axis and rotates, the shape of the processing groove is necessarily limited to a symmetrical cross section. When cutting a groove with an asymmetrical cross section, it is necessary to move a cutting blade having a shape that matches the cross-sectional shape of the groove relatively along the curved path between the workpiece and the cutting edge. Therefore, it is necessary to provide the cutting tool itself with a C-axis rotation that changes the traveling direction along with the curve of the movement trajectory. Therefore, even if the C-axis rotation function is provided, a desired processing dimensional accuracy can be obtained, and the processing cross section of the work can be applied to both symmetrical and asymmetrical cutting processing, and the work can be performed with a fine finish surface roughness. As a result of developing and devising a cutting tool capable of mainly performing grooving, the present applicant has developed an elastically deformable cutting tool which is mounted on a machine tool having a C-axis and performs a cutting process on a work surface. A hail-bit type cutting tool having a slit forming a fulcrum above the cutting blade along a plane orthogonal to the tool axis, and the cutting tool has a shank having an axis coinciding with the C axis. And, a cutting blade of a desired shape is fixed to a mounting surface of the cutting blade formed as a plane including the axis at the tip of the shank by predetermined fixing means, and the elastic deformation fulcrum is in the cutting progress direction of the cutting blade. See the front area of the mounting surface The cutting reaction force is suppressed within a certain range by elastically absorbing the cutting reaction force, and the cutting blade can be moved along the predetermined trajectory while preventing galling and biting. The cutting action is advanced by relatively moving the
Provided is a hail bite type cutting tool that enables a cutting locus to be selected as a curved locus by rotating the shaft, and that can cut an arbitrary processing groove having a symmetrical or asymmetrical cross section on the work surface. 3-74976.

[0004]

However, there is still a need for structural improvements in the above cutting tools. In other words, unlike this type of halebite type cutting tool, unlike many cases in which a cutting action proceeds in a desired cutting direction while gradually providing cutting feed only in the axial direction of the shank of the cutting tool, for example, a vertical A cutting tool with a shaft-shaped shank and a cutting blade with a cutting blade at its tip is mounted on the tool holder of the rotating spindle of the machine tool, and the cutting blade gradually cuts and feeds in the lateral direction substantially perpendicular to the shank axis. When using a cutting blade having a receiving cutting edge and cutting the work side surface rising from the upper surface of the work perpendicular to the shank axis, the slit forming the above-mentioned elastic deformation fulcrum is formed by the shaft center of the shaft-shaped shank. In a structure provided in a plane perpendicular to the plane, the fulcrum of elastic deformation is in that plane, so that when the cutting edge of the cutting blade receives a cutting reaction It can not escape by elastic deformation in a direction that does not contact the click surface. In other words, the direction in which the cutting blade and the cutting blade holder of the shank should elastically deform due to the cutting reaction force from the side of the workpiece is the direction in which the axis of the cutting tool is torsionally deformed. At the fulcrum, only a deformation effect such as bending the cutting blade in the direction opposite to the cutting direction in the axis can be generated. Therefore, there is a problem in that when the cutting edge is deformed by the cutting reaction force, there is a fear that the side surface of the cut work piece may be damaged. Also, in the process of cutting the work surface by gradually receiving the cutting feed in the lateral direction with respect to the axis of the shank of the cutting tool, for the same reason as described above, it may be difficult to prevent galling and biting. The same is true.

Accordingly, an object of the present invention is to provide a shaft-shaped shank having a mounting portion mounted on a tool holding portion of a rotary spindle of a machine tool and a cutting blade holding portion extending from the mounting portion. In a cutting tool having a cutting blade mounted on the cutting blade holding portion of the shank, when performing cutting of the work surface by a cutting blade having a cutting edge that receives a cutting feed at least in a lateral direction with respect to the shank axis. It is an object of the present invention to provide a hail cutting tool having a slit forming an applicable elastic deformation fulcrum.

[0006]

According to the present invention, a cutting blade attached to a tip of a cutting blade holding portion of a shank of a cutting tool has a shank axial center or an axial direction of the cutting blade holding portion of the shank. It has a cutting edge that receives cutting feed in the lateral direction, and during the cutting operation in the predetermined cutting direction, the cutting blade is twisted from the surface to be cut of the work through the cutting edge as if around the axis of the cutting blade holding part. When receiving a cutting reaction force in a direction like this, the elastic deformation corresponding to the reaction force is on an inclined surface that intersects the axis of the cutting blade holder, and in front of the cutting blade when viewed in the cutting direction. The object of the invention described above is achieved by forming a slit in the cutting blade holding portion so as to form a deformation fulcrum in the region.

In other words, according to the present invention, the shaft is formed of a mounting portion fitted to the tool holding portion of the machine, and a cutting blade holding portion extending from the mounting portion to the distal end side. A shank, and a cutting edge attached to a tip of the cutting blade holding portion of the shank and receiving a cutting feed at least in a lateral direction with respect to an axis of the mounting portion, and performing a cutting operation in the cutting direction together with the shank. A cutting edge to be cut, at a predetermined position separated from the tip of the cutting blade holding portion of the shank, on an inclined surface with respect to the axis of the cutting blade holding portion from a back area viewed in the cutting direction to a front area of the cutting blade. And a cutting blade fixing means for attaching and fixing the cutting blade to the cutting blade holding portion of the shank. It is characterized by comprising Than is the cutting tool is provided with.

[0008]

According to the cutting tool of the present invention, an inclined slit formed in a cutting blade holding portion holding a cutting blade having a cutting edge for receiving a cutting feed in a lateral direction with respect to the axis of a shank of the tool has a work surface. Even when a cutting reaction force that causes torsional deformation around the shank axis is applied to the cutting edge, the cutting edge of the cutting blade is elastically deformed to escape in the direction away from the machined surface of the work. Provides a possible deformation fulcrum, so that the work surface of the workpiece is not damaged by the deformation action of the cutting blade itself as the cutting progresses, and the cutting blade is always free to move away from the processed surface of the work As a result, no inconvenience phenomenon such as biting into the workpiece processing surface and galling does not occur. In addition, if at least two inclined slits are formed in a crosswise manner in the cutting blade holding portion of the cutting tool, the cutting feed direction of the cutting blade of the cutting blade is related to the shank axis, and the cutting direction is left and right. In the same manner as described above, the cutting edge which receives the cutting feed in any of the lateral directions does not encounter the fear of giving damage to the work-processed surface, and does not encounter troubles such as galling and biting. Hereinafter, the present invention will be described in more detail based on embodiments shown in the accompanying drawings.

In the cutting tool of the present invention, when the cutting blade advances relative to the work along a predetermined trajectory, the work surface can be cut in accordance with the cutting edge shape of the cutting blade. From the workpiece to the inside, that is, by gradually providing a cut in the lateral direction with respect to the axis of the cutting blade holder, for example, to smoothly cut from roughing to finishing on the side of the work rising from the work plane. Can be carried out. In addition, it goes without saying that the traveling locus of the cutting blade can follow a curved surface locus according to the C-axis rotation given by the rotating main shaft of the machine tool. And the cutting reaction force acting on the cutting blade is
The elastic deformation of the shank at the fulcrum formed in the inner part of the slit cut along the inclined plane is always absorbed and suppressed to a constant level of reaction force by the spring elastic deformation action of the shank. The cutting blade can exhibit a stable cutting force regardless of the cutting depth.

[0010]

FIG. 1 is a front view of a cutting tool according to a first embodiment of the present invention as viewed from the front in a cutting direction, and FIG.
FIG. 3 is a side view of a main part viewed from a direction indicated by an arrow indicated by -2 line.
FIG. 1 is a partial view along arrow A of FIG. 1 showing an inclined slit formed in a cutting blade holding portion of a shank of a cutting tool shown in FIG. 1 and a through hole penetrating a position of an elastic deformation fulcrum formed in an inner part thereof. FIG. 4 is a cross-sectional view taken along a plane perpendicular to the axis for explaining the elastic deformation action of the cutting blade in the cutting tool of the first embodiment. FIG. 5 shows the cutting tool according to the second embodiment of the present invention. FIG. 6 is a side view of a main part of the cutting tool according to the embodiment as viewed from the side, and FIG. 7 is a sectional view taken along line 7-7 of FIG.

1 to 4, a cutting tool 10 according to a first embodiment of the present invention is, as an example, a tool mounting hole 9 of a chuck 8 provided at the tip of a rotating spindle of a vertical machine tool. It is mounted as a tool that performs cutting on the surface of the work by being mounted so that its axis coincides with the axis of rotation “C” and moving relative to the work W along a desired straight or curved locus. , Shank 20, cutting blade 40,
The shank 20 is provided with a set screw 30 forming a fixing means for fixing the cutting blade 40 to the shank 20.

The shank 20 has a long shaft shape, and has a rod-shaped mounting portion 22 fitted and mounted in the mounting hole 9 of the chuck 8 without play, and a chuck end 8a of the mounting portion 22. And a cutting blade holding portion 24 formed as an extended portion that extends downwardly from the position of the cutting blade 22. The mounting portion 22 is securely fastened to the mounting hole 9 of the chuck 8 with an appropriate number of lock screws 18. A screw seat 25 is formed to be attached. When the mounting portion 22 is firmly fixed to the mounting hole 9 with the lock screw 18, the mounting portion 22 has a cylindrical shape having an axis that coincides with the rotation axis C.

On the other hand, the integral cutting blade holding portion 24 extending downward from the mounting portion 22 is provided with a concave portion forming a cutting blade mounting surface 26 for mounting the cutting blade 40 at a lower end thereof.
The cutting blade 40 is inserted into the recessed portion from below, and the back surface 42 is brought into close contact with the cutting blade mounting surface 26, and is pressed from the front surface 44 side by a set screw 30 as a fixing means, and the cutting blade mounting surface 26 is pressed. Fixed to. Here, the cutting blade 40 has a flat plate shape, and has a cutting edge 46 protruding in a lateral direction or a side direction substantially orthogonal to the axial direction of the shank 20 having a shaft body at the lower end. The cutting edge 46 has various blade shapes according to the cutting conditions for the workpiece W. In this embodiment, the cutting edge 46 of the cutting blade 40 is a normal hail bite type cutting tool having the cutting edge 46 in a direction coinciding with the axis of the shank 20 and, further, the C axis of the spindle chuck 8 of the machine tool. Has a cutting edge 46 protruding in the lateral direction (to the left in FIGS. 1 and 4) as described above. Therefore, for example, when the workpiece W is a molding die or the like, In addition, the cutting process is performed by the cutting blade 40 cutting the side surface rising from the bottom surface of the mold from the lower side perpendicular to the plane of FIG. 1 to the upper side. FIGS. 1 and 4 show a state in which the cutting edge 46 of the cutting blade 40 is cutting the side wall surface of the work W in this manner. Of course, the cutting edge 46 may have a blade shape that cuts the bottom surface simultaneously with the side wall surface of the work W.

Here, as clearly shown in FIG.
0 flank 47 extends from the front 44 side of the blade 40 to the rear 42
However, in the process of cutting, the cutting edge 46 successively receives cutting feed toward the inside of the side wall surface of the work W and advances cutting in the above-described cutting direction. A cutting reaction force is received from the side wall surface of the work.
This cutting reaction force is applied to the cutting edge 46 of the cutting blade 40.
Since it acts as a moment force, the cutting tool 10 provided with the cutting blade 40 having the same cutting edge 46 has the shank 2
It will be twisted around the zero axis. That is,
The cutting edge 46 of the cutting blade 40 is subjected to a twisting action such that the cutting edge 46 is displaced from the position indicated by the solid line in FIG. 4 to the position indicated by the dashed line. Therefore, it is important that the tip of the cutting edge 46 does not damage the already cut work surface in the twisting process. The present invention improves the cutting edge 46 of the cutting blade 40 during the displacement process of the cutting edge 46 so that the cutting edge 46 can escape in a direction away from the work surface, and at the same time, the cutting progresses while receiving the cutting reaction force. The present invention provides a cutting tool 10 that does not cause phenomena such as galling and biting in a machining process.

According to the first embodiment of the present invention, the cutting blade holding portion 24 of the shank 20 of the cutting tool 20 has a shank axial center in a region further above the cutting blade mounting surface 26. A slit 28 cut from the back side to the front side of the cutting blade holding portion 24 of the tool 10 along the plane obliquely intersecting with the machine axis "C" and in the cutting direction.
Is provided. As is clear from FIGS. 1 and 2, the slit 28 is formed by cutting the shank axis along the inclined surface, and the inner rear end of the slit 28 extends further forward than the front surface 44 of the cutting blade 40. ing. Further, a through hole 28a (FIG. 3 clearly shows the through hole 28a) which passes through the inner deep end of the slit 28 and obliquely penetrates the cutting blade holding portion 24 is formed. The through hole 28a functions to prevent stress concentration. The center line of the through hole 28a passing through the inner deep end of the slit 28 is inclined with respect to the shank axis, and the fulcrum position of the elastic deformation of the cutting blade holder 24 and the cutting blade 40 below the center line. 28b. Thus, the elastic deformation fulcrum 28b of the cutting blade 40
Are inclined with respect to the shank axis, and are disposed on the line penetrating the cutting blade holding portion 24 at different positions such as distances L1 and L2 from the lower end of the shank. Since the line is disposed in front of the front surface 44 of the cutting blade 40, the cutting blade 40 receives a cutting reaction force from the work surface, in particular, the side wall surface of the work W in FIG. At this time, as described above, the displacement in the torsional direction is such that the cutting blade 40 and the lower region of the cutting blade holding unit 24 are integrally formed along the line of the inclined elastic deformation fulcrum, so to speak, obliquely upward. Occurs. As a result, the cutting edge 46 of the cutting blade 40 can perform an escape operation in a direction away from the work surface. Therefore, it is possible to reliably avoid the problem that the cutting edge 46 comes into contact with the already cut work surface in the deformation process and causes damage, and, of course, the cutting blade 40 and its holding portion Since the cutting edge 24 has an elastic deformation function, the cutting edge 46 can smoothly advance in the cutting direction without causing galling or biting.

In the first embodiment shown, the shank 2
The inclination angle of the slit 28 and the through hole 28a formed in the cutting tool holding portion 24 is approximately 45 degrees with respect to the shank axis or the C axis. When the cutting edge 46 of the workpiece W cuts only the side wall surface of the work W, or when the flat surface where the shank axis vertically intersects with the side wall surface at the same time, the direction of the cutting reaction force received by the cutting process is Needless to say, it is only necessary to select an appropriate inclination angle in response to various changes. Further, in the above-described embodiment, the case where the cutting tool is mounted on the rotating spindle of the vertical machine tool has been described as an example, but the cutting tool of this embodiment is directly mounted on the horizontal rotating spindle of the horizontal machine tool. It can also be applied to cutting work such as planing and finishing of the work surface to avoid galling and biting, etc. It should be understood that cutting can be achieved.

FIGS. 5 to 7 show another embodiment of the cutting tool according to the present invention. In this embodiment, as shown in FIG. 5, in addition to the slit 28 for forming the elastic deformation fulcrum 28b described above, the shank shaft center of the shank 20 of the cutting tool 10 The other slits 128 are provided in a crosswise manner in a substantially symmetrical arrangement with respect to. These slits 28, 12
8 is a shank 20 when viewed in the direction of the cutting process.
Are cut from the back side to the front side of the cutting blade holding portion 24, and the through holes 28a, 128a passing through the inner back end thereof
And has an elastic deformation fulcrum on the center line of the through hole 28a or 128a. That is, in the present embodiment, the former slit 28, the through hole 28a and the latter slit 128, the through hole 128a are provided with two cutting lines that are substantially symmetrical with respect to the axis of the shank, as the fulcrum of the elastic deformation, and The cutting blade attached to the cutting blade holding portion 24 is allowed to undergo elastic deformation in accordance with the cutting reaction force, so that the cutting blade during cutting can be released away from the work surface.

Therefore, in view of the above-described two kinds of elastic deformation fulcrum, the inside of the recess 26 at the lower end of the cutting blade holding portion 24 of the cutting tool 10 of this embodiment is directed toward the work surface as shown in FIG. Cutting blade 40 having cutting edge 46 projecting laterally from the shank axis or cutting edge 1 projecting in the opposite direction
Either one of the cutting blades 140 having the 46 is inserted and fixed using the fixing screw means as in the first embodiment, and the cutting of the workpiece surface is performed. By using the cutting edge 46 or 146 protruding in one of two symmetrical directions perpendicular to both directions of the traveling direction, it is possible to perform a cutting process on a desired surface to be machined on two opposing work surfaces. Becomes At this time, since the cutting process is performed while imparting elastic deformation performance to the cutting blade 40 or 140 by making one of the inclined slits 28 or 128 function, the other slit, that is, the inclined slit 28 is used. In some cases, it is a good measure to invalidate the elastic deformation function of the inclined slit 128 and maintain the rigidity of the entire cutting tool. For this reason, in the present embodiment, each of the shank 20 from the side surface region of the cutting blade holding portion 24 is Screw holes 29a, 29b passing through the slits 28, 128
Alternatively, 129a and 129b are cut in advance, and a bolt (not shown) is screwed into the slit on the side to be invalidated on the screw hole side penetrating the slit, so that the elastic deformation function by the slit is temporarily performed. It can be effectively invalidated. FIG. 7 shows, in particular, the screw holes 29a, 29b, 1
29a and 129b.

As is apparent from the above description, in this embodiment, the cutting tool having the cutting edge 40 or 140 projecting in a direction substantially perpendicular to both the shank axis of the cutting tool 10 and the desired cutting direction. The blade 40 or 140 is selectively inserted, and a cut in the same protruding direction is given to the cutting edge so that the work surface, particularly the work side wall surface rising from the work bottom surface, can be cut. That is,
By simply selecting the cutting blade to be inserted and fixed to the shank 20 of the cutting tool 10 as needed at the site of use, it is possible to perform the desired cutting work on the two work surfaces of the work without causing a galling or biting action. It is something that can be accomplished.

[0020]

As is apparent from the above description, the present invention is characterized in that the cutting blade attached to the tip of the cutting blade holder in the shank of the cutting tool has the shank axis or the shaft of the cutting blade holder of the shank. It has a cutting edge that receives cutting feed in the transverse direction to the center direction, and in the process of performing a cutting operation in a predetermined cutting direction, from the surface to be cut of the work, the cutting blade passes through the cutting edge as if the shaft of the cutting blade holding portion. When subjected to a cutting reaction force in a direction that twists around the center, elastic deformation corresponding to the reaction force is located on an inclined surface that intersects the axis of the cutting blade holding part and is viewed in the cutting direction. The slit is formed in the cutting blade holder so that a deformation fulcrum is formed in the front area of the cutting blade. Can be elastically deformed in the direction away from the workpiece surface. Ri, depending in, it is to an effect called not to rise to problems such as galling and biting by cutting process. In addition, from this point, it is possible to completely avoid inconvenience such as damaging the cut work surface with the cutting edge of the cutting blade, and as a result, it is possible to achieve smooth cutting and high quality of the cut surface. is there.

[Brief description of the drawings]

FIG. 1 is a front view of a cutting tool according to a first embodiment of the present invention as viewed from the front in a cutting traveling direction.

FIG. 2 is a side view of a main part viewed from a direction indicated by an arrow 2-2 shown in FIG.

FIG. 3A shows an inclined slit formed in a cutting blade holding portion of a shank of the cutting tool shown in FIG. 1 and a through hole penetrating a position of an elastic deformation fulcrum formed in an inner part thereof. It is a partial view by an arrow.

FIG. 4 is a cross-sectional view taken along a plane perpendicular to an axis for explaining an elastic deformation action of the cutting blade in the cutting tool of the first embodiment.

FIG. 5 is a rear view of a main part of a cutting tool according to a second embodiment of the present invention as viewed from the rear in a cutting progress direction.

FIG. 6 is a main part side view of the cutting tool according to the embodiment as viewed from the side.

FIG. 7 is a sectional view taken along line 7-7 in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 8 ... Chuck 9 ... Tool mounting hole 10 ... Cutting tool 20 ... Shank 22 ... Mounting part 24 ... Cutting blade holding part 26 ... Cutting blade mounting surface 28 ... Slit 28a ... Through hole 28b ... Elastic deformation fulcrum 30 ... Set screw 40 ... Cutting Blade 46: Cutting blade 47: Escape 128: Slit 128a: Through hole 140: Cutting blade 146: Cutting blade

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B23B 27/02 B23B 29/00 B23D 13/00

Claims (2)

(57) [Claims] 1. A shank formed in a shaft body comprising a mounting portion fitted to a tool holding portion of a machine, and a cutting blade holding portion extending from the mounting portion to a distal end side. A cutting blade attached to the tip of the cutting blade holding portion, having a cutting edge that receives at least a cutting feed in a lateral direction with respect to the axis of the mounting portion, and performing a cutting operation in a predetermined cutting direction together with the shank, A predetermined portion of the cutting blade holding portion of the shank, which is separated from the front end, is cut along a tilted surface with respect to the axis of the cutting blade holding portion from a rear region viewed in the cutting direction to a front region of the cutting blade. And an inclined slit formed at the innermost end as a fulcrum of elastic deformation at the time of cutting action, and attaching the cutting blade to the cutting blade holding portion of the shank,
Cutting tool fixing means for fixing the cutting tool. 2. A cutting machine in which the predetermined portion of the cutting blade holder is cut in a cross-like manner at a position substantially symmetrical with respect to the axis of the cutting blade holder with respect to the inclined slit when viewed in the cutting direction. And an inclined slit, and a screw hole for bolt screwing, which intersects with the two inclined slits from the side region of the cutting blade holding portion, and is cut and penetrated, is further provided on the cutting blade holding portion. 2. The detachable cutting blade according to claim 1, wherein the attached cutting blade is a detachable cutting blade having a cutting edge that receives a cutting feed in at least one of left and right lateral directions with respect to the axis of the mounting portion. 3. Cutting tools.