1. Field of the Invention
The present invention relates to a side cutter in which inserts are removably attached.
2. Description of the Related Art
In a conventionally known side cutter, cartridges, each equipped with a plate-shaped cutting insert, are arranged and fixed on a peripheral portion of a disk-shaped or ring-shaped cutter body. The cutting inserts positioned respectively in the axial both ends and in the center of the cutting body on a peripheral surface thereof are arranged symmetrically to be shifted in cutting positions from each other, and each thereof is fixed from the flank side using an attaching hole by a screw with a head. (For example, refer to Japanese Utility Model Laid-Open No. S49-119871 (1974))
In the cutter described in the above Utility Model Literature, however, since the cutting inserts located on the peripheral surface in the axial both ends and in the center are shifted in cutting positions from each other, the number of the inserts capable of being attached on the cutter body is limited. Therefore, there occurs a problem that the cutter can not increase a cutting efficiency because of no possibility of an increase in the number of effective teeth.
In order to solve the above problem, in a side cutter according to the present invention, the invention according to claim 1 comprises a substantially disk-shaped or substantially ring-shaped cutter body, two or more peripheral cutting inserts each having a cutting edge protruding from a peripheral surface of the cutter body, and two or more corner cutting inserts each having a cutting edge protruding from an end surface of the cutter body. The peripheral cutting inserts and the corner cutting inserts are arranged in the cutter body such that the cutting edges adjacent to each other in a circumferential direction of the cutter body have overlapping rotational trajectories around an axis of rotation of the cutter body. Members of at least one insert set comprising one of the peripheral cutting inserts and one of the corner cutting inserts are spaced from each other along an axial direction of the cutter body and are arranged substantially in the same position in the circumferential direction of the cutter body.
The peripheral cutting insert may be attached to the cutter body by means of a first cartridge and the corner cutting insert forming an insert set with the peripheral cutting insert may be detachably attached to the first cartridge by means of a second cartridge.
The second cartridge may protrude further in a radial direction and an axial direction of the cutter body than the first cartridge.
The side cutter according to the present invention may be provided with a single common chip pocket adjacent to at least an insert set comprising one of the peripheral cutting inserts and one of the corner cutting inserts in a forward side in the circumferential direction of the cutter body.
The peripheral cutting insert and the corner cutting insert may be located alternatingly in the circumferential direction.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).
As an embodiment of the present invention, a side cutter to which the present invention is applied will be explained with the accompanying drawings.
As shown in
The peripheral cutting insert includes a peripheral cutting edge 21 as a cutting edge protruding from the peripheral surface 10c of the cutter body. The corner cutting insert 30 includes a corner cutting edge 31 as a cutting edge provided in an end portion side of the peripheral cutting edge surface 10c of the cutter body to protrude from the end portion. The peripheral cutting inserts 20A and 20B are arranged along the circumferential direction of the cutter body 10 to be positioned alternatingly and in a zigzag manner between one end surface side and the other end surface side of the cutter body 10. Likewise, the corner cutting inserts 30A and 30B are arranged along the circumferential direction of the cutter body 10 to be positioned alternatingly and in a zigzag (alternating) manner between one end surface side and the other end surface side of the cutter body 10.
As shown in
The corner cutting insert 30 is formed in a substantially rectangular plate shape. The rectangular face as an upper face is formed as a flank 33, a side face extending between the upper and lower faces is formed as a rake face 32, and a cutting edge including the corner cutting edge 31 is formed in an intersecting ridgeline portion between the flank 33 and the rake face 32. A ridgeline of a corner portion provided in each end of both the cutting edges is formed as the arc-shaped corner cutting edge 31 as viewed from a direction opposing the rake face 32 of the corner cutting insert 30.
The peripheral cutting insert 20 and the corner cutting insert 30 are provided with attaching holes, each penetrating through the upper and lower faces in a thickness direction. At least the cutting edge of each of the peripheral cutting insert 20 and the corner cutting insert 30 is formed of a hard material such as cemented carbide, cermet or ceramics or an ultra-high pressure sintered compact such as polycrystal diamond or cubic boron nitride.
The peripheral cutting insert 20 and the corner cutting insert 30 each are attached to the cutter body 10 by means of a cartridge 40, 50, respectively. The inserts 20 and 30 each are detachably fixed to their respective cartridges by threading a screw member such as a flat head screw having a head capable of being engaged to an inner wall face of each of the attaching holes into a female screw hole attached in the cartridge. The cartridges include a large-sized first cartridge 40 and a small-sized second cartridge 50. The large-sized cartridge 40 has a circumferentially facing front surface 40a and radially outwardly facing top surface 40b. Similarly, the small-sized cartridge 50 has a circumferentially facing front surface 50a and radially outwardly facing top surface 50b. The first cartridge 40 has a width substantially equal to that of the cutter body 10. The second cartridge 50 is fixed to a recessed portion 42 formed in the side portion of the first cartridge 40. Thus, one can consider the second cartridge 50 to be seated in the first cartridge 40.
As shown in
Further, a rising engagement face 13 protruding forward in the cutter rotational direction K is formed on the circumferential support face 11a of the recessed groove 11 to extend along a direction normal to the rotational axis of the cutter body 10. A notch engagement face 43 capable of being engaged to the rising engagement face 13 is formed on the side face of the first cartridge 40 contacting with the circumferential support face 11a. The axial position of the first cartridge 40 is determined by allowing the notch engagement face 43 to be engaged to the rising engagement face 13 in the circumferential support face 11a of the recessed groove. In addition, the first cartridge 40 is fixed by a first screw member 60 screwed into a female screw hole formed in the circumferential support face of the recessed groove 11. The first screw member 60 is, for example, a hexagon socket bolt with a head fitting in the cartridge 40. The female screw hole is inclined to a normal line of the circumferential support face 11a to be directed toward the cutter radial inside and the rising engagement face 13 (see
The second cartridge 50 is inserted into a recessed portion 42 notched in the side face of the first cartridge 40. A wall face of the recessed portion 42 directed in the cutter rotational direction K is formed as a second cartridge circumferential support face 42a. A wall face directed in the cutter radial outside is formed as a second cartridge radial support face 42b. A wall face of the cutter body directed in the axial direction is formed as a second cartridge axial support face 42c. The second cartridge support faces 42a, 42b and 42c respectively contact and support the side faces of the second cartridge 50 opposing these support faces, thereby positioning the second cartridge 50 in the recessed portion 42 of the first cartridge 40.
In addition, the second cartridge 50 is fixed by two second screw members 70 screwed into female screw holes formed in the second cartridge axial support face 42c of the recessed portion 42. Each of the two second screw members 70 is, for example, a hexagon socket bolt with a head fitted in the cartridge 50. The female screw hole is inclined to a normal line of the second cartridge axial support face 42c to be directed toward the circumferential support face side and the radial support face side, and therefore the second cartridge 50 is pressed against all the second cartridge support faces 42a, 42b and 42c to be fixed thereon.
The peripheral cutting insert 20 is screwed-retained by a screw member in an insert seat 41 formed in the first cartridge 40. The insert seat 41 is formed in an intersecting ridgeline portion between a radially outwardly directed first side face of the first cartridge 40 and a circumferentially directed second side face of the first cartridge 40, the circumferentially directed second side face being directed forward in the cutter rotational direction K. Thus, the peripheral cutting insert 20 is attached by means of the first cartridge 40 to the cutter body 10.
The corner cutting insert 30 is screwed-retained by a screw member in an insert seat 51 formed in the second cartridge 50. In the seated cartridge 50, the insert seat 51 is formed in an intersecting ridgeline portion between an axially directed first side face positioned at one end face side of the cutter body 10 and a circumferentially directed second side face, which directed forward in the cutter rotational direction K. The corner cutting insert 30 is screwed in the insert seat 51 by screw members. That is, the corner cutting insert 30 is attached to the cutter body 10 by means of the second cartridge 50 and further by means of the first cartridge 40. In other words, the large-sized first cartridge 40 and the small-sized second cartridge 50 attached to the first cartridge 40 have a parent-child relation to each other, with the small-sized second cartridge 50 being seated in the large-sized cartridge 40.
As described above, the peripheral cutting inserts 20A and 20B and the corner cutting inserts 30A and 30B are arranged along the circumferential direction of the cutter body 10 to be positioned alternatingly and in a zigzag manner between one end surface side and the other end surface side of the cutter body 10. When the peripheral cutting insert 20A proximate the first cutter end surface 10a of the cutter body 10 is attached in the first cartridge 40, the associated corner cutting insert 30B proximate the second cutter end surface 10b is attached in the second cartridge 50 which has been attached integrally with the first cartridge 40 (see
The peripheral cutting insert 20 and the associated corner cutting insert 30 attached in each first cartridge 40 are spaced from each other in the axial direction of the cutter body 10 as viewed from the side of the side cutter (see
Further, the peripheral cutting insert 20 and the associated corner cutting insert 30 share a single chip pocket 12 which they have in common formed adjacent thereto in a circumferentially forward cutter rotational direction K. The chip pocket 12 is formed in a large size by notching the peripheral surface 10c of the cutter body 10, to form a radially inwardly directed recess having a curved face. The chip pocket 12 is also opened to both the end surfaces 10a and 10b of the cutter body 10. The curved face is connected to a radially outwardly directed side face of the wedge member 80 which, in turn, is adjacent to the first cartridge 40 in a circumferentially forward cutter rotational direction K.
The peripheral cutting inserts and the corner cutting inserts are arranged in insert sets, each insert set comprising one peripheral cutting insert and one corner cutting insert which are spaced from each other in an axial direction of the cutter body and are arranged substantially in the same position in the circumferential direction of the cutter body. Thus, cutting inserts 20A, 30B can be considered to constitute a first set of cutting inserts and the cutting inserts 20B, 30A can be considered to constitute a second set of cutting inserts. In the circumferential direction of the side cutter, alternating insert sets reverse the axial order of the peripheral cutting insert and the corner cutting insert. Thus, in the circumferential direction, the combined peripheral and corner cutting edges 21, 31 of the first insert set at least partially overlap the combined peripheral and corner cutting edges 21, 31 of the second insert set (see
The fact that the peripheral cutting inserts and the corner cutting inserts (20A and 30B, and 20B and 30A) are arranged substantially in the same position in the circumferential direction of the cutter body 10 means that both the inserts (20A and 30B, and 20B and 30A) at least partially overlap from each other in the circumferential direction (refer to
The side cutter described above is attached in a main spindle of a machine tool, rotated around its rotational axis and fed in a direction normal to the rotational axis. A cutting edge of each insert attached in the cutter body 10 contacts a workpiece. In addition, the side cutter forms a groove in a workpiece, the groove having a cross sectional configuration substantially similar to a rotational trajectory at the time of rotating the cutting edge of each insert 20 and 30 around the rotational axis.
According to this side cutter, since the peripheral cutting inserts and the corner cutting inserts (20A and 30B, and 20B and 30A) are arranged substantially in the same position in the circumferential direction of the cutter body 10, the number of the inserts which can be installed in the cutter body 10 can be increased. Accordingly, the present side cutter can further improve a cutting efficiency by increasing the number of effective teeth as compared to a conventional tool.
In the present side cutter, the peripheral cutting insert 20 is attached in the cutter body 10 by means of the first cartridge 40 and the corner cutting insert 30 forming an insert set with the peripheral cutting insert 20 is removably attached to the first cartridge 40 by means of the second cartridge 50. By adopting such a configuration, one may arrange the peripheral cutting insert and the corner cutting insert substantially in the same position in the circumferential direction of the cutter body 10. On the other hand, if the peripheral cutting insert and the corner cutting insert were attached to the cutter body by means of independently mounted cartridges (i.e., each of the two cartridges being directly mounted to the cutter body), this would result in reduction in strength of the cutter body and of the respective cartridges. However, the side cutter according to the present embodiment can arrange the peripheral cutting insert and the corner cutting insert substantially in the same position in the circumferential direction of the cutter body without reduction in strength of the cutter body 10, the first cartridge 40 and the second cartridge 50.
Furthermore, the peripheral cutting insert and the corner cutting insert (20A and 30B, and 20B and 30A) have the single chip pocket 12 in common formed adjacent to these inserts in a forward side in the cutter rotational direction K. Therefore, strength and rigidity in the vicinity to the peripheral surface 10c of the cutter body are increased. Further, since the chip pocket 12 is formed in a large size to be opened to both the end surfaces 10a and 10b of the cutter body, it is capable of accommodating chips generated by each cutting edge of the peripheral cutting insert 20A and the corner cutting insert 30 and smoothly discharging them to outside.
In the corner cutting insert 30, there is selected a curvature radius of the corner cutting edge corresponding to a radius of an arc-shaped portion of the corner portion in the groove to be cut. A side cutter exemplified in
Even in a case of replacing a first corner cutting insert 30 for a second corner cutting insert 30 having a different outer dimension, it is only required to replace the second cartridge 50 alone. That is, a replacement job of the corner cutting insert 30 can be carried out very easily and in short time without removing the cutter body 10 from the main spindle of the machine tool or removing the large-sized first cartridge 40 from the cutter body 10, and therefore the workability in replacing the corner cutting insert 30 can be largely improved. Further, the removal operation of the second cartridge 50 can be performed in a stationary state of the cutter body 10 without removing the cutter body 10 from the main spindle of the machine tool, since the screw member 70 for fixing the second cartridge 50 can be operated from the end surface side of the cutter body 10. In this respect also, an improvement of the workability can be accomplished.
It is preferable that the second cartridge 50 protrudes in the cutter radial direction and in the axial direction more than the first cartridge 40. In other words, it is preferable that the first cartridge 40 is positioned more inward in the cutter radial direction and in the axial direction than the second cartridge 50. This is because the second cartridge 40 inhibits breakages such as chipping of the corner cutting insert 30 performing the cutting of the arc-shaped portion of the corner portion in the groove having a relatively high load to prevent such damage from spreading to the first cartridge 50. For the same reason, for preventing the damage from spreading to the cutter body 10, it is preferable that the cutter body 10 is positioned more inward in the cutter radial direction and in the axial direction than the first cartridge 40.
Further, as seen in
In this embodiment, an attaching posture of the corner cutting insert 30 to the cutter body 10 is different from that of the embodiment explained previously. That is, while the corner cutting insert 30 of the previous embodiment is arranged in such a manner that the thickness direction is positioned along the axial direction of the cutter body 10, the corner cutting insert 30 of the present embodiment is arranged in such a manner that the thickness direction is positioned along the radial direction of the cutter body. (Refer to
As illustrated in
The cutting edge of the corner cutting insert 30 is inclined to the rotational axis of the cutter body 10 in such a manner as to gradually head backward in the cutter rotational direction from the corner cutting edge 31 toward an obtuse corner portion of the parallelogram face. In consequence, a positive axial rake angle is given to the cutting edge. In addition, as shown in
The second cartridge 50 is, similarly to the previous embodiment, fixed by using the screw members 70 such as bolts with hexagon holes having heads fitted in the second cartridge 50, and an additional screw member 70 is added in a position closer to the corner cutting edge 31 of the corner cutting insert 30 than in the previous embodiment as a result of changing an attaching posture of the corner cutting insert 30, and the second cartridge 50 is fixed by a total of three screw members 70.
In the second embodiment explained above, by changing the attaching posture of the corner cutting insert 30 to the cutter body 10, a main component force acting in the cutter rotational direction K acts equally substantially over the entire cutting edge of the corner cutting insert 30. That is, the main component force acts on one section of the parallelogram of the corner cutting insert 30, and equally substantially over an entire side face connecting to the other section opposing the one section and contacting with the second cartridge 50. Therefore, the side face is stably supported and restrained by the second cartridge 50. In addition, the main component force acts on the screw member for fixing the corner cutting insert 30 in both sides in the axial directions of the cutter body 10, thereby restraining a behavior for the corner cutting insert 30 to rotate around an axis line of the screw member. Therefore, since the corner cutting insert 30 is stably and accurately fixed in the second cartridge 50 during cutting, deterioration of the cutting accuracy can be restricted.
Further, in the present embodiment, a screw member 70 is added in a position closer to the corner cutting edge 31 of the corner cutting insert 30 than in the previous embodiment and the second cartridge 50 is fixed by in total the three screw members 70, thus fixing the second cartridge more strongly. As a result, since the corner cutting insert 30 is accurately fixed to the cutter body 10, deterioration of the cutting accuracy can be restricted.
The present invention is not limited to the embodiments explained above, and may be applied to the configuration that an inner peripheral insert and a corner cutting insert are attached on a inner peripheral surface of a ring-shaped cutter body. In addition, the peripheral cutting insert may have three or more-edge lines, and in a case of four or more-edge lines, two peripheral cutting inserts may be attached to a single first cartridge.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
Number | Date | Country | Kind |
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JP2008-226682 | Sep 2008 | JP | national |
This is a Continuation-in-part of International Application No. PCT/JP2009/065517 filed Sep. 4, 2009, which published as WO 2010/027055A1 on Mar. 11, 2010 and claims the benefit of Japanese Patent Application No. 2008-226682, filed Sep. 4, 2008. The contents of the aforementioned applications are hereby incorporated by reference herein in their entirety.
Number | Date | Country | |
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Parent | PCT/JP2009/065517 | Sep 2009 | US |
Child | 13040556 | US |