Pressing member, tool body and cutting tool

Abstract

To provide a pressing member, a tool body and a cutting tool, capable of increasing the number of cutting elements mounted and reducing the size of the tool body.SOLUTION: A pressing member 50 is configured to be inserted into a pocket 12 of a tool body 10 for pressing and fixing a cutting insert 40 placed in a mounting part 13 of the pocket 12 onto a mounting surface 13a of the mounting part 13. The pressing member includes: a wedge part 51 having a contacting surface 55 that comes into contact with an inner surface of the pocket 12, and a pressing surface 56 that is in contact with the cutting insert 40, wherein the pressing surface 56 is formed so as to gradually come close to the contacting surface 55 in an insertion direction D into the pocket 12 with respect to the contact surface 55; and a pressure-receiving part 52 that is pushed in the insertion direction D by a fastening component 70 that is screwed into the pocket 12.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a pressing member, a tool body, and a cutting tool.

Background Art

[0002] In a cutting tool such as an insert-exchangeable cutter, a plurality of cutting inserts are radially mounted on the tip of a tool body. These cutting inserts are fixed in pockets provided at the tip of the tool body by a pressing member (see, for example, Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a cutting tool, the more cutting inserts are mounted, the more efficiently machining can be performed. For this reason, it is attempted to reduce the thickness of the cutting insert and increase the number of mounted inserts. Further, by reducing the thickness of the cutting insert, the cutting tool itself can be downsized.

[0005] However, since the space at the tip of the tool body is occupied by the pressing member that fixes the cutting insert, even if the cutting insert is thinned, an increase in the number of mounted cutting inserts and downsizing of the tool body are restricted. For this reason, further improvement is desired for increasing the number of mounted cutting inserts and downsizing the tool body.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a pressing member, a tool body, and a cutting tool that can increase the number of cutting tools mounted and reduce the size of the tool body. **Means for Solving the Problems**

[0007] A pressing member according to an aspect of the present invention is a pressing member that is inserted into a pocket of a tool body and presses and fixes a cutting tool disposed on a mounting portion of the pocket against a mounting surface of the mounting portion, and has a contact surface that contacts the inner surface of the pocket and a pressing surface that abuts against the cutting tool, and a wedge portion in which the pressing surface gradually approaches the contact surface in the insertion direction into the pocket with respect to the contact surface, and a pressure receiving portion that is pushed in the insertion direction by a fastening component screwed into the pocket.

[0008] In the pressing member having the above structure, since the pressure receiving portion is pushed by the fastening component, the wedge portion has a structure of being pushed into the pocket. Therefore, a female screw portion into which a screw for pushing into the pocket is screwed can be eliminated, and the size can be reduced. And since this pressing member is reduced in size, the number of cutting tools mounted on the tool body can be increased, or the cutting tool itself can be reduced in size.

[0009] In a state where the cutting tool is fixed, the contact position of the pressure receiving portion with the fastening component may be arranged at a position facing the cutting tool rather than at the end surface in the insertion direction of the cutting tool into the mounting portion.

[0010] In a state where the cutting tool is fixed, at least a part of the pressure receiving portion may be surrounded by the inner peripheral surface of a holding hole portion that is further recessed from the pocket over the entire circumference in the circumferential direction.

[0011] The thickest part of the wedge portion may be smaller than the diameter of the fastening component.

[0012] The wedge portion may have a housing recess in which at least a part of the fastening component is housed, and the wall surface on the rear side in the insertion direction in the housing recess may be a drawing surface that is pressed by the fastening component that is loosened from the pocket.

[0013] The wall surface on the front side in the insertion direction in the receiving recess may be a pressing surface that is pressed by the fastening component together with the pressure receiving portion.

[0014] The wedge portion may have protruding portions that protrude outward on both sides.

[0015] The protruding portion may not interfere with the pocket in a state where the cutting tool is fixed and may be able to contact the pocket when the cutting tool is removed.

[0016] The tool body according to one aspect of the present invention includes the above-described pressing member, a base portion formed with a plurality of pockets spaced in the circumferential direction into which the pressing member is inserted, and a fastening component screwed into the pockets. The pockets have a mounting portion where the cutting tool is disposed. The pressing member inserted into the pockets by the fastening component screwed into the pockets is pressed in the insertion direction into the pockets, whereby the cutting tool disposed in the mounting portion is pressed against the mounting surface of the mounting portion and fixed.

[0017] The cutting tool according to one aspect of the present invention includes the above-described tool body and a cutting tool disposed in the mounting portion of the pocket formed in the base portion of the tool body.

Advantages of the Invention

[0018] According to the present invention, there are provided a pressing member, a tool body, and a cutting tool that can increase the number of mounted cutting tools and reduce the size of the tool body.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (Cutting Tool) As shown in FIG. 1, the cutting tool 100 according to the present embodiment includes a tool body 10 and a cutting insert 40. The tool body 10 has a pressing member 50 and a fastening part 70.

[0021] A plurality of cutting inserts 40 are mounted on the tip of the tool body 10 of the cutting tool 100 and are arranged radially at intervals in the circumferential direction. The cutting tool 100 is a turning tool such as an indexable cutter, and cuts a workpiece with the cutting insert 40 at the tip of the tool body 10 while rotating. In this example, the cutting insert 40 is exemplified as the cutting tool mounted on the tool body 10, but the cutting tool includes a form in which the cutting insert 40 is assembled to a cartridge.

[0022] (Tool Body) The tool body 10 has a base portion 11 that is generally cylindrical, and this base portion 11 is attached to the rotating shaft of a machine tool such as a machining center.

[0023] As shown in FIGS. 2 to 4, the base portion 11 of the tool body 10 has a plurality of pockets 12 at its tip. A pressing member 50 and a fastening component 70 are arranged in the pocket 12. Further, the pocket 12 has a mounting portion 13. This mounting portion 13 is formed, for example, in a groove shape or a concave shape, and a cutting insert 40 is arranged in this mounting portion 13. The cutting insert 40 arranged in the mounting portion 13 is fixed by the pressing member 50 and the fastening component 70.

[0024] The mounting portion 13 has a mounting surface 13a and a contact surface 13b. The cutting insert 40 accommodated in the mounting portion 13 is brought into contact with the mounting surface 13a and the contact surface 13b. Further, the front end side of the base portion 11 of the mounting portion 13 is open, and a positioning surface 13c is provided on the rear end side of the base portion 11.

[0025] The pocket 12 has a wedge accommodating portion 21 and a fastening hole portion 22. The wedge accommodating portion 21 is provided on the mounting portion 13 side in the pocket 12, and the fastening hole portion 22 is provided on the side opposite to the mounting portion 13 with respect to the wedge accommodating portion 21. These wedge accommodating portion 21 and fastening hole portion 22 are gradually inclined toward the mounting portion 13 side toward the back which is the center side in the radial direction of the base portion 11 (see FIG. 3). Further, the depth of the wedge accommodating portion 21 is larger than that of the mounting portion 13, and further, a holding hole portion 22a, which will be described later, of the fastening hole portion 22 has a depth larger than that of the wedge accommodating portion 21.

[0026] The wedge accommodating portion 21 has a sliding surface 21a on the side opposite to the mounting portion 13. Further, guide ridges 21b are formed along the depth direction on both inner side surfaces on the mounting portion 13 side in the wedge accommodating portion 21.

[0027] The fastening hole portion 22 is successively from the back, a holding hole portion 22a, a threaded hole portion 22b, and a lead-in hole portion 22c, and is gradually increased in diameter. A female thread is formed on the inner peripheral surface of the threaded hole portion 22b.

[0028] The threaded hole portion 22b and the introduction hole portion 22c have a part of their circumferential direction communicating with the wedge accommodating portion 21. The holding hole portion 22a has a part of its circumferential direction communicating with the wedge accommodating portion 21 at its rear end side.

[0029] (Cutting insert) The cutting insert 40 has a base metal 41 and a cutting edge tip 42. The base metal 41 is formed in a rectangular plate shape, and the cutting edge tip 42 is provided at one corner portion on its upper surface. The cutting edge tip 42 provided on this base metal 41 is, for example, a tip of single crystal diamond or diamond sintered body (PCD).

[0030] The cutting insert 40 is mounted from the end opposite to the cutting edge tip 42 to the mounting portion 13 of the pocket 12. This cutting insert 40 is gradually thickened in the mounting direction to the mounting portion 13.

[0031] (Pressing member) As shown in FIGS. 5 to 11, the pressing member 50 is inserted into the pocket 12 of the base portion 11 of the tool body 10, and is a member that presses and fixes the cutting insert 40 disposed in the mounting portion 13 of the pocket 12 to the mounting surface 13a of the mounting portion 13.

[0032] This pressing member 50 has a wedge portion 51 and a pressure receiving portion 52. When the pressing member 50 is inserted into the pocket 12, the wedge portion 51 is inserted into the wedge accommodating portion 21, and the pressure receiving portion 52 is inserted into the fastening hole portion 22.

[0033] The wedge portion 51 has a contact surface 55 and a pressing surface 56. The contact surface 55 contacts the sliding surface 21a of the wedge housing portion 21 which is the inner surface of the pocket 12, and the pressing surface 56 abuts against the cutting insert 40 disposed on the mounting portion 13. The wedge portion 51 is formed in a wedge shape whose thickness gradually decreases in the insertion direction D (see FIG. 3) into the pocket 12. Thereby, in the wedge portion 51, the pressing surface 56 is inclined so as to gradually approach the contact surface 55 in the insertion direction D into the pocket 12 with respect to the contact surface 55. The thickness at the rear end portion in the insertion direction D of this wedge portion 51 is the thickest portion, and this thickest portion has a thickness smaller than the diameter of the fastening component 70.

[0034] Further, the wedge portion 51 has protrusion portions 57 protruding outward on both side portions thereof. These protrusion portions 57 are formed in parallel to the contact surface 55 along the insertion direction D of the wedge portion 51 into the pocket 12. The upper and lower corners of this protrusion portion 57 are formed in a shape that is recessed in an arc shape (see FIG. 11). Note that the upper and lower corners of the protrusion portion 57 may be formed in a tapered shape.

[0035] The pressure receiving portion 52 is formed in a columnar shape and is integrally formed on the contact surface 55 side of the wedge portion 51. The pressure receiving portion 52 is disposed on the front side in the insertion direction D of the wedge portion 51, and a part thereof protrudes to the front side in the insertion direction D from the wedge portion 51. This pressure receiving portion 52 has an axis center parallel to the contact surface 55 of the wedge portion 51.

[0036] Further, the pressing member 50 has a housing recess 60 in the wedge portion 51. A part of the fastening component 70 is housed in this housing recess 60. The housing recess 60 is formed on the contact surface 55 side of the wedge portion 51 and is formed in a shape that is recessed in an arc shape in a cross-sectional view. The front side wall surface in the insertion direction D of this housing recess 60 is flush with the end surface of the pressure receiving portion 52, and together with the end surface of the pressure receiving portion 52, it is a pushing surface 61. Further, the rear side wall surface in the insertion direction D of the housing recess 60 is a pulling surface 62 (see FIG. 8). Further, a relief recess 63 is formed at the upper edge of the rear side wall portion in the insertion direction D of the housing recess 60.

[0037] (Fastening component) The fastening component 70 accommodated in the accommodation recess 60 of the pressing member 50 is, for example, a hollow set screw (sweet potato screw) having an external thread on its outer periphery. This fastening component 70 has a tool hole 71 on its rear end surface for a tool to engage. The tool hole 71 is not limited to a hexagonal hole that a hexagonal wrench can engage, but may be a hole having a shape that various tools such as a Torx (registered trademark) hole can engage. This fastening component 70 is configured to be screwable into a threaded hole portion 22b formed in the fastening hole portion 22 of the pocket 12.

[0038] The fastening component 70 has a larger diameter than the pressure receiving portion 52 of the pressing member 50, and in a state of being accommodated in the accommodation recess 60, the axis center coincides with that of the pressure receiving portion 52. Note that the axis center of the fastening component 70 does not necessarily coincide with the axis center of the pressure receiving portion 52. Further, in a state where the fastening component 70 is accommodated in the accommodation recess 60, the circumscribed circle that is the rotation locus of the tool hole 71 of the fastening component 70 does not reach the wall portion on the rear side in the insertion direction D of the accommodation recess 60 having a relief recess 63 on its upper edge. Thereby, the tool inserted into the tool hole 71 does not interfere with the wall portion on the rear side in the insertion direction D of the accommodation recess 60. Thus, by forming the relief recess 63 in the wall portion on the rear side in the insertion direction D of the accommodation recess 60, the wedge portion 51 of the pressing member 50, which is difficult to thin due to interference with the tool, can be made thinner.

[0039] (Fixing of cutting insert) Next, a case of attaching the cutting insert 40 to the pocket 12 provided in the base portion 11 of the tool body 10 will be described.

[0040] First, insert a pressing member 50, which has a fastening component 70 accommodated in an accommodation recess 60, into a pocket 12 of a base portion 11 of a tool body 10. Specifically, while inserting the tip of a pressure receiving portion 52 of the pressing member 50 into a holding hole portion 22a in a fastening hole portion 22 of the pocket 12, insert a wedge portion 51 of the pressing member 50 into a wedge accommodation portion 21 and loosely screw the fastening component 70 into a screw hole portion 22b. In this state, the pressing member 50 is maintained in a state of being disposed within the pocket 12 with protrusions 57 on both side portions of the wedge portion 51 locked to guide ridges 21b of the wedge accommodation portion 21.

[0041] Next, insert and dispose a cutting insert 40 into a mounting portion 13 of the pocket 12. Thereby, bring the cutting insert 40 into contact with a mounting surface 13a, a contact surface 13b, and a positioning surface 13c. Note that the cutting insert 40 may be inserted and disposed in the mounting portion 13 of the pocket 12 before inserting the pressing member 50 into the pocket 12.

[0042] Thereafter, insert a tool into a tool hole 71 of the fastening component 70 accommodated in the accommodation recess 60 of the pressing member 50, and screw the fastening component 70 into a screw hole portion 22b formed in the fastening hole portion 22 of the pocket 12.

[0043] In this way, when the fastening component 70 is screwed into the screw hole portion 22b, the fastening component 70 moves toward the depth of the fastening hole portion 22. Thereby, the pressing surface 61 of the pressing member 50 is pressed by this fastening component 70, and the pressing member 50 is pushed into the depth of the pocket 12. Then, the wedge portion 51 of the pressing member 50 moves toward the depth of the wedge accommodation portion 21 while sliding a contact surface 55 on a sliding surface 21a of the wedge accommodation portion 21, so that the pressing surface 56 moves in a direction approaching the cutting insert 40 and comes into contact with a base metal 41 of the cutting insert 40.

[0044] When the fastening component 70 is further screwed in, the base metal 41 of the cutting insert 40 is pressed by the pressing surface 56 of the wedge portion 51 of the pressing member 50. As a result, the cutting insert 40 is firmly clamped and fixed between the mounting surface 13a of the mounting portion 13 and the pressing surface 56 of the wedge portion 51 of the pressing member 50. Thereby, the cutting insert 40 is fixed to the pocket 12 of the base portion 11 of the tool body 10.

[0045] In this way, since the pressing member 50 is structured to be pushed into the pocket 12 by the fastening component 70, the female screw portion for screwing the screw for pushing into the pocket 12 can be eliminated, and miniaturization can be achieved.

[0046] Also, in the state where the cutting insert 40 is fixed by the pressing member 50, the contact position Cs of the pressing member 50 with the fastening component 70 at its pressure receiving portion 52 is arranged at a position facing the cutting insert 40 on the rear side of the end face 40a (the two-dot chain line in FIG. 3) in the insertion direction D of the cutting insert 40 into the mounting portion 13 (see FIG. 3). Thereby, the bending moment generated when the pressure receiving portion 52 is pressed by the fastening component 70 can be suppressed. That is, the pressing member 50 is designed to suppress the bending moment generated when the cutting insert 40 is fixed and to consider stress relaxation. Therefore, it can be miniaturized while ensuring sufficient strength of the pressing member 50.

[0047] Furthermore, in the state where the cutting insert 40 is fixed by the pressing member 50, a part of the tip of the pressure receiving portion 52 is inserted into the holding hole portion 22a of the fastening hole portion 22 of the pocket 12. That is, a part of the tip of the pressure receiving portion 52 is surrounded by the inner peripheral surface of the holding hole portion 22a of the pocket 12 over the entire circumference in the circumferential direction (see FIG. 3). Thereby, the inclination of the pressure receiving portion 52 pressed by the fastening component 70 can be suppressed, and miniaturization can be achieved while ensuring sufficient pressing force of the cutting insert 40 by the pressing surface 56 of the wedge portion 51.

[0048] In addition, in the state where the cutting insert 40 is fixed by the pressing member 50, the protrusions 57 on both sides of the wedge portion 51 are separated from the guide ridges 21b of the wedge housing portion 21 and are in a non-contact state with respect to the pocket 12. Therefore, the pressing force for pressing the cutting insert 40 due to the interference of the protrusion 57 with the pocket 12 does not decrease.

[0049] (Removal of the cutting insert) Next, the case of removing the cutting insert 40 fixed to the pocket 12 by the pressing member 50 will be described.

[0050] To remove the cutting insert 40, the fastening component 70 is rotated in the direction opposite to the fastening direction by a tool inserted into the tool hole 71. Then, the fastening component 70 screwed into the threaded hole portion 22b formed in the fastening hole portion 22 of the pocket 12 is loosened and moves in the removal direction opposite to the insertion direction D.

[0051] Then, the pulling surface 62 of the pressing member 50 is pressed by this fastening component 70, and the pressing member 50 is pulled out from the pocket 12. As a result, the pressing surface 56 of the wedge portion 51 of the pressing member 50 moves in a direction away from the cutting insert 40, and the pressing of the cutting insert 40 by the pressing member 50 is released. In this state, the cutting insert 40 disposed in the mounting portion 13 of the pocket 12 is gripped and removed from the mounting portion 13.

[0052] Here, the pressing member 50 pulled out from the pocket 12 together with the fastening component 70 has the protrusions 57 on both sides of the wedge portion 51 contacting and being locked to the guide ridges 21b of the wedge housing portion 21. That is, when removing the cutting insert 40, the protrusions 57 formed on the wedge portion 51 of the pressing member 50 abut against the guide ridges 21b of the pocket 12 and are guided, so that the pressing member 50 does not tilt and the fastening component 70 does not come off from the accommodation recess 60. Therefore, the pressing member 50 is smoothly pulled out from the pocket 12 together with the fastening component 70. Note that depending on the posture when loosening the pressing member 50 with a tool, the protrusions 57 formed on the wedge portion 51 may not contact the guide ridges 21b of the pocket 12. Further, the cutting insert 40 can be detachably exchanged in a loosened state without completely removing the pressing member 50 and the fastening component 70 from the pocket 12.

[0053] As described above, according to the pressing member 50 according to the present embodiment, since the pressure receiving portion 52 is pushed in by the fastening component 70, the wedge portion 51 has a structure of being pushed into the pocket 12. Therefore, the female screw portion into which the screw for pushing into the pocket 12 is screwed can be eliminated, and miniaturization can be achieved. And since this pressing member 50 is miniaturized, the number of cutting inserts 40 mounted on the tool body 11 can be increased, or the cutting tool 100 itself can be miniaturized.

[0054] Further, since the thickest part of the wedge portion 51 of the pressing member 50 is smaller than the diameter of the fastening component 70, the thickness of the wedge portion 51 can be suppressed and the pressing member 50 can be further miniaturized.

Explanation of Reference Numerals

[0055] 10 Tool body 11 Base portion 12 Pocket 13 Mounting portion 13a Mounting surface 40 Cutting insert (cutting tool) 40a End face 50 Pressing member 51 Wedge portion 52 Pressure receiving portion 55 Contact surface 56 Pressing surface 57 Protrusion 60 Receiving recess 61 Insertion surface 62 Extraction surface 70 Fastening component 100 Cutting tool Cs Contact position D Insertion direction

Claims

1. A pressing member that is inserted into a pocket of a tool body and is disposed on a mounting portion of the pocket, and presses and fixes a cutting tool disposed on a mounting surface of the mounting portion, having a contact surface that contacts an inner surface of the pocket and a pressing surface that abuts against the cutting tool, and a wedge portion in which the pressing surface gradually approaches the contact surface in a direction of insertion into the pocket with respect to the contact surface, a pressure receiving portion that is pushed in the insertion direction by a fastening component screwed into the pocket, and having, a pressing member.

2. In a state where the cutting tool is fixed, a contact position of the pressure receiving portion with the fastening component is disposed at a position facing the cutting tool rather than an end surface in a direction of insertion of the cutting tool into the mounting portion, The pressing member according to claim 1.

3. In a state where the cutting tool is fixed, at least a part of the pressure receiving portion is surrounded by an inner peripheral surface of a holding hole portion that is further recessed from the pocket over the entire circumference in the circumferential direction, The pressing member according to claim 1.

4. The wedge portion has a thickest portion smaller than the diameter of the fastening component, The pressing member according to claim 1.

5. The wedge portion has a receiving recess in which at least a part of the fastening component is received, a drawing surface that is pressed by the fastening component that can be loosened from the pocket, is provided on a wall surface on the rear side in the insertion direction in the receiving recess, The pressing member according to claim 1.

6. a pushing surface that is pressed by the fastening component together with the pressure receiving portion, is provided on a wall surface on the front side in the insertion direction in the receiving recess, The pressing member according to claim 5.

7. The wedge portion has protruding portions that protrude outward on both side portions, The pressing member according to claim 1.

8. The protruding portion, in a state where the cutting tool is fixed, does not interfere with the pocket, and can contact the pocket when the cutting tool is removed, The pressing member according to claim 7.

9. The pressing member according to any one of claims 1 to 8, a base portion having a plurality of pockets formed at intervals in the circumferential direction and into which the pressing member is inserted, a fastening component screwed into the pocket, and having, the pocket has a mounting portion where the cutting tool is disposed, the pressing member inserted into the pocket by a fastening component screwed into the pocket is pressed in a direction of insertion into the pocket, so that the cutting tool disposed on the mounting portion is pressed against and fixed to a mounting surface of the mounting portion, a tool body.

10. The tool body according to claim 9, a cutting tool disposed at the mounting portion of the pocket formed in the base portion of the tool body; comprising a cutting tool.

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