Rolling Tools

Abstract

To provide a rolling tool capable of restraining frictional resistance between a pedestal and a die when the die rotates.SOLUTION: A groove 12a is recessed in a seat surface 12 of a pedestal 10. The groove 12a is a recessed groove with a semicircular cross-section and is formed in an annular ring shape concentric with the central axis of the seat surface 12. Thus, with a rolling tool 1, a contact area between the seat surface 12 of the pedestal 10 and an axial end surface of a die 30 can be reduced by an amount of recess of the groove 12a and lubrication oil held in the groove 12a can be supplied between the pedestal 10 (the seat surface 12) and the die 30 (an axial end surface). Accordingly, frictional resistance between the pedestal 10 (the seat surface 12) and the die 30 (the axial end surface) can be restrained when the die 30 rotates.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a rolling tool, and more particularly to a rolling tool capable of suppressing frictional resistance between a base and a die when the die rotates. [Background technology]

[0002] Patent Document 1 discloses a rolling die (rolling tool) including a die piece 1 (base) having an insertion hole 2 (receiving hole) for receiving a workpiece, a plurality of pins 4 (axial support members) disposed on the die piece 1 (base), and a plurality of screw rollers 3 (dies) rotatably supported on the pins 4 (axial support members) and disposed around the insertion hole 2 (receiving hole) of the die piece 1 (base). Patent Documents 2 and 3 also disclose rolling tools of a similar structure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-174566 A [Patent Document 2] Japanese Patent Application Publication No. 3-35927 [Patent Document 3] Japanese Utility Model Application Publication No. 55-148838 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology described above, the axial end face of the die is pressed against the seat surface of the base during rolling, which causes a problem of large frictional resistance between the base and the die when the die rotates.

[0005] The present invention has been made to solve the above-mentioned problems, and has an object to provide a rolling tool that can reduce frictional resistance between a base and a die when the die rotates. [Means for solving the problem]

[0006] In order to achieve this object, the rolling tool of the present invention comprises a base having a receiving hole for receiving a workpiece, a plurality of support members disposed on the base, and a plurality of dies rotatably supported by the support members and disposed around the receiving hole of the base, and a groove is formed in at least one of the seat surface of the base or the axial end surface of the dies. The groove is formed in a spiral shape, and the spiral direction when moving radially inward is the rotation direction of the die. do. In addition, the rolling tool of the present invention has a base having a receiving hole for receiving a workpiece, a plurality of support members arranged on the base, and a plurality of dies rotatably supported on the support members and arranged around the receiving hole of the base, wherein a groove is recessed into at least one of the seat surface of the base or the axial end surface of the die, the groove is formed extending radially, and the radially outer end of the groove is positioned radially outer than the outer edge of the axial end surface of the die. In addition, the rolling tool of the present invention has a base having a receiving hole for receiving a workpiece, a plurality of support members arranged on the base, and a plurality of dies rotatably supported on the support members and arranged around the receiving hole of the base, wherein grooves are recessed into at least one of the seating surface of the base or the axial end faces of the dies, the grooves are recessed into the seating surface of the base, and the groove width of the groove in the area opposite the receiving hole relative to the support members is larger than the groove width of the groove in the area on the receiving hole side relative to the support members. Effect of the Invention

[0007] Claim 1 , claim 2 and claim 6 According to the described rolling tool, a groove is recessed into at least one of the seating surface of the base or the axial end surface of the die, thereby reducing the contact area between the base and the die and enabling the lubricating oil held in the groove to be supplied between the base (seating surface) and the die (axial end surface), thereby suppressing the frictional resistance between the base and the die when the die rotates.

[0008]

[0009] Also, Claim 1 According to the described rolling tool, the grooves are formed in a spiral shape, and the direction of the spiral when moving radially inward is the direction of rotation of the die, so that the lubricating oil can be easily supplied to the radially inward side of the die as the die rotates during rolling, thereby suppressing the frictional resistance between the base and the die when the die rotates.

[0010] Claim 2 According to the rolling tool described ,groove is formed extending in the radial direction, and the radially outer end of the groove is located radially outward from the outer edge of the axial end face of the die, so that lubricating oil supplied to the region of the seat surface of the base that is radially outward from the outer edge of the axial end face of the die can be received from the radially outer end of the groove. This makes it easier to supply lubricating oil to the radially inward side. As a result, frictional resistance between the seat and the die when the die rotates can be suppressed.

[0011] Claim 3 According to the rolling tool described in claim 2 In addition to the effects of the rolling tool described above, the grooves are curved in a convex shape toward the direction of rotation of the die, which makes it easier to supply lubricating oil to the radially inward side of the die as the die rotates during rolling, thereby reducing frictional resistance between the base and the die when the die rotates.

[0012] Claim 4 According to the rolling tool described in claim 2 or 3 In addition to the effect of the rolling tool described in 2, the groove width of the groove on the radially inner side is made larger than the groove width of the groove on the radially outer side, so that the contact area between the base and the die can be reduced on the radially inner side, thereby suppressing the frictional resistance between the base and the die when the die rotates.

[0013] Claim 5 According to the rolling tool described in claim 2 from 4 In addition to the effects of the rolling tool described in any one of the above, the groove depth of the groove on the radially inner side is made larger than the groove depth of the groove on the radially outer side, so that the amount of lubricating oil held in the groove can be made larger on the radially inner side, thereby suppressing the frictional resistance between the base and the die when the die rotates.

[0014] Claim 6 According to the rolling tool described ,shaft Since the groove width in the region opposite the receiving hole to the support member is made larger than the groove width in the region on the receiving hole side of the support member, when the support member is deflected by the pressure during rolling, the contact area between the base and the die can be reduced in the region where the axial end face of the die is pressed against the seating surface of the base, thereby suppressing the frictional resistance between the base and the die when the die rotates. [Brief description of the drawings]

[0015] [Figure 1]1A is a front view of a rolling tool and a holder in a first embodiment of the present invention, and FIG. 1B is a partially enlarged cross-sectional view of the rolling tool and the holder taken along line Ib-Ib in FIG. [Diagram 2] 2(a) is a front view of the base, and (b) is a cross-sectional view of the base taken along line IIb-IIb in FIG. 2(a). [Diagram 3] 3(a) is a bottom view of the pivot member, and (b) is a side view of the pivot member as viewed in the direction of arrow IIIb in FIG. 3(a). [Figure 4] 4(a) is a front view of the holding member, and (b) is a cross-sectional view of the holding member taken along line IVb-IVb in FIG. 4(a). [Diagram 5] 5(a) is a bottom view of the regulating member, and (b) is a cross-sectional view of the regulating member taken along line Vb-Vb in FIG. 5(a). [Figure 6] 11(a) to 11(c) are partially enlarged front views of rolling tools in second to fifth embodiments, respectively. [Figure 7] 13(a) is a partially enlarged cross-sectional view of a rolling tool in a first modified example, and FIG. 13(b) is a schematic front view of a seating surface in a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, the overall configuration of a rolling tool 1 and a holder 100 will be described with reference to Fig. 1. Fig. 1(a) is a front view of the rolling tool 1 and the holder 100 in the first embodiment of the present invention, and Fig. 1(b) is a partially enlarged cross-sectional view of the rolling tool 1 and the holder 100 taken along line Ib-Ib in Fig. 1.

[0017] 1, the rolling tool 1 includes a disk-shaped base 10 having a receiving hole 11 for receiving a workpiece formed therethrough along a central axis, a plurality of support members 20 disposed on the base 10, a plurality of dies 30 rotatably supported by the support members 20 and disposed around the receiving hole 11 of the base 10, and a draw bolt 40 for fixing the support members 20 to the base 10, and is attached to an automatic lathe or a turret lathe via a holder 100, and forms (rolls) a small-diameter (for example, M12 or less) male thread in the workpiece. In this embodiment, the number of dies 30 disposed is three.

[0018] The die 30 is formed in a cylindrical shape with a through hole 31 running along the central axis, and a plurality of annular threads 32 having no lead are formed on its outer circumferential surface (five threads in this embodiment).

[0019] Therefore, the die 30 is attached to the base 10 in a position inclined by the lead angle of the male thread (hereinafter referred to as the "machined thread") to be formed in the workpiece with respect to the central axis of the base 10. The die 30 is also attached to the base 10 with the mounting height positions differing by a predetermined amount (in this embodiment, 1 / 3 of the lead (pitch) of the machined thread) so as to match the lead of the machined thread.

[0020] FIG. 2(a) is a front view of the base 10, and FIG. 2(b) is a cross-sectional view of the base 10 taken along line IIb-IIb in FIG. 2(a).

[0021] The base 10 is formed with a receiving hole 11, a seat 12 that supports the axial end face of the die 30, a mounting hole 13 to which the support member 20 is attached, an insertion hole 14 for inserting the pull-in bolt 40, a seat 15 that supports the head of the pull-in bolt 40, a plurality of slits 16 extending radially outward from the receiving hole 11 in a radially straight line, and a fastening hole 17 into which a hexagonal socket set screw 50 is fastened.

[0022] A plurality of grooves 12a (two in this embodiment) are recessed into the seat surface 12. The grooves 12a are recessed grooves having a semicircular cross section, and are formed (extended) in an annular shape centered on the central axis of the support member 20 (i.e., the rotation axis of the die 30).

[0023] The bearing surface 12, the mounting hole 13 and the insertion hole 14 are formed concentrically, and the central axes of the bearing surface 12, the mounting hole 13 and the insertion hole 14 are disposed at positions that are equidistant from the central axis of the base 10 and equidistant in the circumferential direction. Also, as described above, the central axes of the bearing surface 12, the mounting hole 13 and the insertion hole 14 are inclined by the lead angle of the machined screw with respect to the central axis of the base 10.

[0024] The seating surfaces 12 and 15 are formed as planes perpendicular to the central axis. The inner diameter of the mounting hole 13 is larger than the inner diameter of the insertion hole 14, and the bottom of the mounting hole 13 has a bottom surface 13a formed as a plane perpendicular to the central axis (i.e., a plane parallel to the seating surfaces 12 and 15).

[0025] The fastening hole 17 is drilled radially of the base 10 toward the central axis of the mounting hole 13, and an internal thread is formed on its inner peripheral surface. Therefore, by pressing the axial end face (tip face) of the hexagon socket set screw 50 fastened in the fastening hole 17 against the shaft support member 20 (D-cut surface 21b), it is possible to restrict the shaft support member 20 from rotating (see FIG. 1).

[0026] An adjustment bolt (not shown) is fastened to the base 10 in a manner that crosses one of the slits 16, and by changing the amount of fastening of the adjustment bolt (changing the spacing of the slits 16), the spacing of the dies 30 (the distance from the central axis of the base 10) can be adjusted.

[0027] FIG. 3(a) is a bottom view of the pivot member 20, and FIG. 3(b) is a side view of the pivot member 20 as viewed in the direction of arrow IIIb in FIG. 3(a).

[0028] The shaft support member 20 includes a shaft-shaped shaft portion 21 and a head portion 22 that projects from the upper end of the shaft portion 21 in a flange-like shape.

[0029] The shaft portion 21 is a portion that is inserted into the mounting hole 13 of the base 10 and the through hole 31 of the die 30 (see FIG. 1(b)), and is set to have an outer diameter that is equal to or slightly smaller than the inner diameters of the mounting hole 13 and the through hole 31. In this way, the die 30 is rotatably arranged (axially supported) at a predetermined position on the base 10 by the axial support member 20 (shank portion 21).

[0030] The head portion 22 is a portion for holding the die 30 between itself and the seat surface 12 of the base 10 , and is set to have an outer diameter larger than the inner diameter of the through hole 31 of the die 30 .

[0031] A fastening hole 21a is recessed from the lower end of the shaft portion 21 along the central axis of the shaft support member 20, and a part of the outer circumferential surface is cut away to have a D-shaped cross section to form a D-cut surface 21b. An internal thread is threaded into the inner circumferential surface of the fastening hole 21a so that a draw bolt 40 can be fastened, and the axial end surface (tip surface) of a hexagon socket set screw 50 can be crimped onto the D-cut surface 21b (see FIG. 1).

[0032] Here, the length dimension H3 of the shaft portion 21 is set to a dimension α larger than the sum of the thickness dimension H1 (see FIG. 1(b)) of the die 30 and the depth dimension H2 (see FIG. 2(b)) of the mounting hole 13 (H1+H2=H3+α). In this embodiment, the dimension α is set to 0.01 to 0.05 mm.

[0033] The die 30 is attached to the base 10 by drawing the support member 20 with a draw bolt 40 fastened to the shaft portion 21 (fastening hole 21a) of the support member 20 and seating the tip surface (axial end surface) of the support member 20 (shaft portion 21) on the bottom surface 13a of the mounting hole 13. This reduces the number of steps in the attachment work and allows accurate formation of a clearance between the die 30 seated on the seat surface 12 and the head 22 of the support member 20.

[0034] That is, in the structure in which the support member is pressed into the mounting hole, the amount of press-in must be finely adjusted so that the rotation of the die is not hindered by pressing the support member too much, which requires advanced technology and a lot of man-hours for adjustment work. On the other hand, in the structure in which the male thread on the outer circumferential surface of the support member is fastened to the female thread on the inner circumferential surface of the mounting hole, the crest is formed in a shape that can abut (fit tightly or bite into) the bottom of the mating member, and since the rotation resistance is large, the support member is prone to breakage due to the fastening force. In addition, when the die is reversed after rolling is completed, the contact pressure with the die can cause the support member to rotate and fall off.

[0035] In contrast, the structure of this embodiment eliminates the need for clearance adjustment work, and can improve the efficiency of the work of mounting the die 30 to the base 10. Also, damage to the pivot member 20, etc. can be suppressed. Furthermore, by restricting the rotation of the pivot member 20 when the die 30 is reversed after the completion of rolling, it is possible to suppress the pivot member 20 (die 30) from falling off.

[0036] In particular, when the thread to be machined is small in diameter (for example, M12 or less, particularly M10 or less), the rolling tool 1 becomes small and the absolute value of the clearance also becomes small accordingly, so advanced technology is required for adjusting the clearance. Therefore, the rolling tool 1 in this embodiment (the fixing structure of the shaft support member 20 by the pull-in bolt 40) is effective.

[0037] FIG. 4(a) is a front view of the holding member 110, and FIG. 4(b) is a cross-sectional view of the holding member 110 taken along line IVb-IVb in FIG. 4(a).

[0038] The holding member 110 includes a shank portion 111 that is held by an automatic lathe or a turret lathe, and a body portion 112 that is formed concentrically with the shank portion 111. A through hole 113 for receiving a workpiece is drilled in the shank portion 111 and the body portion 112 along the central axis of the holding member 110.

[0039] The body 112 is formed into a cylindrical shape with a bottom, with a disk-shaped bottom and a cylindrical peripheral wall, and the inner diameter of the body 112 (peripheral wall) is set to a dimension equal to or slightly smaller than the outer diameter of the base 10. A plurality of fastening holes 112a are drilled in the body 112 (peripheral wall), and the tip (pointed tip) of a hexagon socket set screw (not shown) fastened to the fastening hole 112a is fitted into a recess (not shown) in the outer peripheral surface of the base 10, thereby fixing the base 10 to the holding member 110 (body 112).

[0040] A male thread 112b is formed on the outer circumferential surface of the body 112. The male thread 112b is a thread formed about the central axis of the holding member 110, and is capable of being screwed into the female thread 121a of the restricting member 120 (outer fitting portion 121).

[0041] 5(a) is a bottom view of the regulating member 120, and FIG. 5(b) is a cross-sectional view of the regulating member 120 taken along line Vb-Vb in FIG. 5(a).

[0042] The restricting member 120 includes an outer fitting portion 121 formed in a cylindrical shape, and a disk-shaped protruding portion 122 protruding radially inward from one axial end of the outer fitting portion 121.

[0043] An internal thread 121a is threaded on the inner circumferential surface of the outer fitting portion 121. The internal thread 121a is a thread formed around the central axis of the restricting member 120, and is capable of being screwed into the external thread 112b of the holding member 110.

[0044] A plurality of recesses 121b are recessed on the outer circumferential surface of the outer fitting portion 121. The recesses 121b are recesses that receive the pins of a hook pin spanner, and the restricting member 120 can be rotated with respect to the holding member 110 using the hook pin spanner.

[0045] A plurality of fastening holes 121c are drilled in the outer fitting portion 121 toward the central axis of the regulating member 120, and an internal thread is threaded on the inner peripheral surface of the fastening holes 121c. Therefore, by pressing the axial end face (tip face) of a hexagon socket set screw (not shown) fastened in the fastening hole 121c against the outer peripheral surface of the holding member 110 (body portion 112), it is possible to regulate the rotation of the regulating member 120 relative to the holding member 110.

[0046] A circular opening in a front view (axial view) is drilled in the protruding portion 122 concentrically with the central axis of the restricting member 120, and the inner peripheral surface of the opening serves as a restricting surface 122a. The restricting surface 122a is a portion that comes into contact with the head 22 of the pivot support member 20, and is formed as a tapered surface whose diameter decreases in the direction away from the outer fitting portion 121 (base 10) (see FIG. 1).

[0047] In addition, the minimum inner diameter of the regulating surface 122a is set to a dimension smaller than the inner diameter of a circumscribing circle that circumscribes each of the heads 22 of the multiple support members 20 when viewed in the axial direction of the rolling tool 1, and the maximum inner diameter of the regulating surface 122a is set to a dimension larger than the inner diameter of the circumscribing circle (see Figure 1).

[0048] Returning to Fig. 1, a method of using the rolling tool 1 and the holder 100 will be described. First, the tightening amount (the interval of the slits 16) of the adjustment bolt (not shown) of the base 10 of the rolling tool 1 is changed to adjust the interval between the dies 30 (the distance between each die 30 and the central axis of the base 10).

[0049] Next, after the rolling tool 1 is held by the holding member 110, the female thread 121a of the regulating member 120 is screwed into the male thread 112b of the holding member 110, and the amount of screwing is adjusted so that the regulating surface 122a of the regulating member 120 is abutted against the outer edge (the ridge portion between the outer peripheral surface and the axial end face) of the head 22 of the support member 20.

[0050] As a result, the rolling tool 1 is held by the holder 100, and the workpiece is ready for thread rolling. To roll threads on the workpiece, first, the workpiece (a round bar-shaped material) is inserted into the receiving hole 11 of the rolling tool 1 (base 10) while supplying lubricating oil to the seating surface 12 or the die 30. As a result, as the die 30 rotates in the forward direction (forward rotation), a thread is raised on the outer circumferential surface of the workpiece. Next, the workpiece is moved in the opposite direction to the insertion direction. As a result, the die 30 is rotated in the reverse direction (reverse rotation) while the workpiece is removed from the receiving hole 11 and the die 30, and the rolling is completed.

[0051] In this case, if the support member 20 is bent radially outward from the base 10 due to the pressure during rolling, a taper is formed in the thread of the workpiece, and the outer diameter and effective diameter deviate from the standard values. In contrast, according to the holder 100, the regulating surface 122a of the regulating member 120 (projection portion 122) abuts against the head 22 of the support member 20 from the radially outer side of the base 10, so that the support member 20 can be prevented from being bent radially outward due to the pressure during rolling. As a result, the gap between the dies 30 is prevented from widening, and the thread of the workpiece can be formed with high accuracy.

[0052] Furthermore, according to the holder 100, the relative position of the head 22 of the pivot member 20 and the protruding portion 122 (restriction surface 122a) of the restricting member 120 in the axial direction of the base 10 can be adjusted by changing the amount of engagement of the restricting member 120 (female thread 121a) with the holding member 110 (male thread 112b). This ensures the versatility of the holder 100. That is, even when pivot members 20 with different overall lengths are used, the same restricting member 120 can be used.

[0053] In particular, in this embodiment, since the restriction surface 122a is a tapered surface, the relative position between the head 22 of the pivot support member 20 and the restriction surface 122a of the protruding portion 122 in the radial direction of the base 10 can also be adjusted.

[0054] Therefore, as described above, even if the tightening amount of the adjustment bolt of the base 10 is changed and the spacing between the dies 30 (the distance between each die 30 and the central axis of the base 10) is adjusted, the regulating surface 122a of the protrusion 122 can be abutted against the head 22 of the support member 20 by changing the amount of engagement of the regulating member 120 (female thread 121a) with the holding member 110 (male thread 112b).

[0055] Furthermore, after the regulating surface 122a of the protrusion 122 is abutted against the head 22 of the support member 20, the regulating member 120 can be further screwed (threaded) into the holding member 110 to bend the support member 20 radially inwardly of the base 10, thereby adjusting (narrowing) the spacing between the dies 30.

[0056] Therefore, when adjusting the distance between the dies 30, there is no need to remove the rolling tool 1 from the holder 100 (holding member 110) and perform the complicated adjustment using the adjustment bolts described above, but rather it is sufficient to simply rotate the regulating member 120 relative to the holding member 110, and this can be done while the tool is still attached to the automatic lathe or turret lathe. As a result, the workability of the adjustment work can be improved.

[0057] Here, during rolling, the axial end face of the die 30 is pressed against the seat surface 12 of the base 10. Therefore, frictional resistance between the base 10 and the die 30 increases when the die 30 rotates (rotates forward), and the base 10 and the die 30 are easily worn. Furthermore, if the rotation of the die 30 is hindered by the above-mentioned frictional resistance during rolling, the die 30 is likely to chip and rolling defects are likely to occur in the thread of the workpiece.

[0058] In contrast, according to the rolling tool 1, the groove 12a is recessed in the seating surface 12 of the base 10, so that the contact area between the base 10 (seating surface 12) and the die 30 (axial end surface) can be reduced. Also, the lubricating oil held in the groove 12a can be supplied between the base 10 (seating surface 12) and the die 30 (axial end surface) during rolling. This makes it possible to suppress the frictional resistance between the base 10 and the die 30 when the die 30 rotates. As a result, it is possible to suppress the wear and chipping of the die 30 and the occurrence of defective rolling of the threads.

[0059] In particular, according to this embodiment, the groove 12a is formed in an annular shape centered on the central axis of the support member 20 (i.e., the rotation axis of the die 30), so that when the die 30 rotates (forward rotation) during rolling, the lubricating oil held in the groove 12a can be easily supplied over the entire circumference in the circumferential direction. As a result, the frictional resistance between the seat 10 (seat surface 12) and the die 30 (axial end surface) when the die 30 rotates can be suppressed.

[0060] In this embodiment, the groove 12a is recessed into the base 10 (seat surface 12). Here, the die 30 is a part (a part that is replaced frequently) that is expected to be replaced due to wear of the thread 32, etc. Therefore, by recessing the groove 12a into the base 10, which is replaced less frequently, the manufacturing cost can be reduced compared to a configuration in which the groove 12a is recessed into the die 30.

[0061] Next, a rolling tool 201 in a second embodiment will be described with reference to Fig. 6(a). Note that the same parts as those in the first embodiment described above are given the same reference numerals and the description thereof will be omitted.

[0062] Fig. 6(a) is a partially enlarged front view of the rolling tool 201 in the second embodiment. Note that the arrow A in Fig. 6(a) indicates the forward rotation direction of the die 30 (the direction in which the die 30 rotates while building up a thread on the outer circumferential surface of the workpiece when the workpiece is inserted toward the receiving hole 11). The arrow A is the same in the following figures, so its description will be omitted.

[0063] 6(a), a groove 212a, which is a recessed groove having a semicircular cross section, is recessed into the seating surface 12 of the rolling tool 201 in the second embodiment. The groove 212a extends in a spiral shape centered on the central axis of the mounting hole 13 (the rotation axis of the die 30). The groove width and groove depth of the groove 212a are set to be approximately constant (approximately the same dimensions) in the extension direction of the groove 212a.

[0064] The winding direction of the groove 212a (spiral) is set such that the winding direction toward the radially inward side of the seating surface 12 (the central axis side of the seating surface 12) is set to the forward rotation direction (arrow A direction) of the die 30. That is, when the groove 212a is traced along the forward rotation direction (arrow A direction) of the die 30, the groove 212a is formed as a spiral with a winding direction that gradually faces the radially inward side of the seating surface 12.

[0065] Here, it is preferable that the lubricating oil be distributed over the entire surface between the seat surface 12 and the die 30 (axial end surface), but it is more difficult to supply lubricating oil to the radial inner side of the die 30 compared to the radial outer side of the die 30.

[0066] That is, when the workpiece is moved in the direction to be pulled out from the rolling tool 1 and a gap is formed between the seating surface 12 and the die 30, the lubricating oil flows into the gap (between the seating surface 12 and the die 30). In this case, the gap between the shaft portion 21 of the support member 20 and the through hole 31 of the die 30 is small, and the gap is covered by the head portion 22 of the support member 20. Therefore, the lubricating oil flows into the gap between the seating surface 12 and the die 30 from the radially outer side of the die 30, and the lubricating oil is difficult to be supplied to the radially inner side of the die 30.

[0067] In contrast, according to the rolling tool 201, the groove 212a is formed in a spiral shape with the winding direction when heading toward the radially inward side of the seating surface 12 (the central axis side of the seating surface 12) being the forward rotation direction of the die 30, so that the lubricating oil held in the groove 212a can be caused to flow and easily supplied to the radially inward side of the die 30 as the die 30 rotates (forward rotation) during rolling. As a result, the lubricating oil can be easily distributed over the entire surface between the seating surface 12 and the die 30 (axial end surface), and the frictional resistance between the base 10 (seating surface 12) and the die 30 (axial end surface) when the die 30 rotates can be suppressed.

[0068] An end E1 of the groove 212a located on the radially outer side of the seating surface 12 is located radially outer than the outer edge of the axial end face of the die 30. This allows the lubricating oil supplied to a region radially outer than the outer edge of the axial end face of the die 30 to be received from the end E1 of the groove 212a and the grooves 212a in its vicinity. This makes it easier to supply the lubricating oil further radially inward of the die 30 as the die 30 rotates.

[0069] An end E2 of the groove 212a located on the radially inner side of the seating surface 12 is connected to the inner circumferential surface of the mounting hole 13. That is, a part of the inner circumferential surface of the mounting hole 13 is cut out by the groove 212a (end E2), and the internal space of the mounting hole 13 and the internal space of the groove 212a are connected to each other. This allows the lubricating oil held in the groove 212a to be supplied from the end E2 to the shaft portion 21 of the support member 20. Therefore, wear of the shaft portion 21 of the support member 20 and the through hole 31 of the die 30 can be suppressed.

[0070] Next, rolling tools 301 to 501 in the third to fifth embodiments will be described with reference to Fig. 6(b) to Fig. 6(d). Note that the same parts as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

[0071] 6(b), 6(c) and 6(d) are partially enlarged front views of the rolling tool 301 in the third embodiment, the rolling tool 401 in the fourth embodiment and the rolling tool 501 in the fifth embodiment.

[0072] As shown in Fig. 6(b) to Fig. 6(d), grooves 312a to 512a, which are semicircular recessed grooves in cross section, are recessed into the seating surface 12 of the rolling tools 301 to 501 in the third to fifth embodiments. These grooves 312a to 512a are a plurality of recessed grooves extending in the radial direction of the seating surface 12 and arranged at equal intervals in the circumferential direction. The groove width and groove depth of the grooves 312a to 512a are set to be approximately constant (approximately the same dimensions) in the extension direction of the grooves 312a to 512a.

[0073] As shown in Figure 6(b), groove 312a extends radially in a straight line from the central axis of the seating surface 12 (the rotation axis of the die 30) toward the radially outward side, and grooves 412a, 512a extend radially while curving from the central axis of the seating surface 12 (the rotation axis of the die 30) toward the radially outward side, as shown in Figures 6(c) and 6(d).

[0074] Groove 412a is formed as a curved arc that is convex in the direction of forward rotation of die 30 (the direction of arrow A), and groove 512a is formed as a curved arc that is convex in the direction of reverse rotation of die 30 (the direction opposite to the direction of arrow A).

[0075] The ends E1 of the grooves 312a-512a located on the radially outer side of the seating surface 12 are located radially outer than the outer edge of the axial end face of the die 30, and the ends E2 of the grooves 312a-512a located on the radially inner side of the seating surface 12 are connected to the inner circumferential surface of the mounting hole 13. As a result, according to the rolling tools 301-501, as in the case of the second embodiment described above, it is possible to easily receive lubricating oil from the end E1 side and supply it to the radially inner side of the die 30, and to supply lubricating oil from the end E2 side, thereby suppressing wear of the shaft portion 21 of the shaft support member 20 and the through hole 31 of the die 30.

[0076] 6(c), the rolling tool 401 has the groove 412a formed as a curved arc that is convex in the direction of forward rotation of the die 30 (the direction of the arrow A), so that the lubricating oil held in the groove 412a flows with the rotation of the die 30 during rolling (the direction of the arrow A), and can be easily supplied to the radially inward side of the die 30. As a result, the lubricating oil can be easily distributed over the entire surface between the seating surface 12 and the die 30 (the axial end surface), and the frictional resistance between the seating 10 (the seating surface 12) and the die 30 (the axial end surface) when the die 30 rotates can be suppressed.

[0077] On the other hand, according to the rolling tool 501, as shown in Fig. 6(d), the groove 512a is formed as a curved arc that is convex in the reverse rotation direction of the die 30 (opposite the direction of the arrow A), so that the lubricating oil held in the groove 512a can be made to flow and easily supplied to the radially inward side of the die 30 with the rotation of the die 30 (rotation in the direction opposite to the arrow A) when the workpiece is moved in the direction of being pulled out of the rolling tool 501. As a result, the lubricating oil can be easily distributed over the entire surface between the seating surface 12 and the die 30 (axial end surface), and the frictional resistance between the seating 10 (seating surface 12) and the die 30 (axial end surface) when the die 30 rotates can be suppressed.

[0078] The present invention has been described above based on the above embodiment, but the present invention is not limited to the above form in any way, and it can be easily inferred that various modifications and improvements are possible within the scope that does not deviate from the spirit of the present invention.

[0079] The numerical values ​​given in the above embodiments are merely examples, and other numerical values ​​can of course be adopted. For example, the number of the dies 30, the number of the grooves 12a to 512a, or the size of the dimension α are arbitrary and can be set appropriately.

[0080] A part or all of the above-mentioned embodiments or modifications may be combined with or replaced by a part or all of the other embodiments or modifications. For example, the groove 412a in the fourth embodiment and the groove 512a in the fifth embodiment may be arranged alternately in the circumferential direction. In this case, the lubricating oil held in the grooves can be caused to flow and easily supplied to the radially inward side of the die 30 during both forward and reverse rotation of the die 30.

[0081] In the above embodiments, the grooves 12a to 512a have a semicircular cross-sectional shape, but the cross-sectional shape may be any shape. For example, the cross-sectional shape may be a rectangular shape. In the third to fifth embodiments, the cross-sectional shape of the grooves 312a to 512a may be such that the groove depth varies in the circumferential direction of the seating surface 12. A preferred example of such a shape will be described as a first modified example with reference to FIG. 7(a).

[0082] Fig. 7(a) is a partially enlarged cross-sectional view of a rolling tool 601 in the first modified example, and corresponds to the cross section taken along line VIIa-VIIa in Fig. 6(b). As shown in Fig. 7(a), the groove 612a of the rolling tool 601 in the first modified example has a groove depth on one circumferential side (the side in the direction of arrow A) of the seating surface 12 that is deeper than the groove depth on the other circumferential side (the side opposite to the direction of arrow A).

[0083] According to the rolling tool 601, the groove depth on the rotation direction side (the side of the arrow A) of the die 30 during rolling can be increased to thicken the film thickness of the lubricating oil. Therefore, compared to a case in which the groove depth is approximately constant in the circumferential direction of the seating surface 12, for example, the lubricating oil (oil film) can be made to act effectively against the pressure that the seating surface 12 receives from the die 30 (axial end surface) during rolling.

[0084] In the above embodiments, the groove width and groove depth of the grooves 12a to 512a are set to be substantially constant (substantially the same dimension) in the extension direction of the grooves 12a to 512a, but the groove width and / or groove depth of the grooves 12a to 512a may be changed in the extension direction of the grooves 12a to 512a. For example, the groove width and / or groove depth may be changed continuously or stepwise (in a staircase-like manner) in the entire region (range from end E1 to end E2) in the extension direction of the grooves 12a to 512a. Alternatively, only a part of the region in the extension direction may be made different from the other regions.

[0085] In the above third to fifth embodiments, it is preferable to make the groove width and / or groove depth of the grooves 312a-512a on the radial inner side of the seating surface 12 larger than the groove width and / or groove depth of the grooves 312a-512a on the radial outer side of the seating surface 12. By making the groove width larger on the radial inner side of the seating surface 12 to which lubricating oil is difficult to be supplied, the contact area between the seating surface 12 and the die 30 can be reduced, and by making the groove depth larger, the amount of lubricating oil held in the grooves 312a-512a can be increased. As a result, the frictional resistance between the seating surface 12 and the die 30 (axial end surface) when the die 30 rotates can be suppressed.

[0086] In the above embodiments, the contact area between the seat 12 and the die 30 (axial end surface) is substantially uniform in the circumferential direction of the seat 12, but the contact area may be made smaller in a portion (hereinafter referred to as a "predetermined region") in the circumferential direction of the seat 12. A preferred example of such an embodiment will be described as a second modified example with reference to Fig. 7(b).

[0087] Fig. 7(b) is a schematic front view of the seating surface 12 in the second modified example. In the second modified example, the predetermined area is defined as an area at an angle θ located on the opposite side of the mounting hole 13 with respect to the receiving hole 11 as shown in Fig. 7(b). In other words, the predetermined area is an area on the side where the axial end face of the die 30 is pressed against the seating surface 12 when the bearing member 20 is deflected radially outward of the base 10 due to the pressure during rolling.

[0088] According to this second modified example, even if the axial support member 20 is deflected due to the pressure during rolling, the contact area between the seating surface 12 and the die 30 (axial end surface) can be reduced in the region on the side where the die 30 (axial end surface) is pressed (i.e., the predetermined region side). As a result, the frictional resistance between the seating surface 12 and the die 30 when the die 30 rotates can be effectively suppressed. In particular, the second modified example is effective in a structure in which the holder 100 does not include the regulating member 120 and the deflection of the axial support member 20 cannot be suppressed.

[0089] The angle θ is an angle centered on the central axis of the mounting hole 13, and the predetermined area is bisected by an imaginary line connecting the central axis of the base 10 (receiving hole 11) and the central axis of the mounting hole 13 when viewed from the front of the seat 12. The angle θ is preferably 60 degrees or more and 180 degrees or less, and more preferably 120 degrees or more and 180 degrees or less. This is to reduce the number of steps for recessing the grooves and ensure the strength of the seat 12, while increasing the effect of reducing the contact area.

[0090] Specific examples of this include, first, in each of the above embodiments, a configuration in which grooves 12a-512a are recessed only in a predetermined region, and recessing grooves 12a-512a in regions other than the predetermined region is omitted; second, in the third to fifth embodiments, a configuration in which the circumferential spacing of grooves 312a-512a in a predetermined region is made smaller than the circumferential spacing of grooves 312a-512a in regions other than the predetermined region; and third, in the third to fifth embodiments, a configuration in which the groove width of grooves 312a-512a in a predetermined region is made larger than the groove width of grooves 312a-512a in regions other than the predetermined region.

[0091] In each of the above embodiments, the grooves 12a to 512a are recessed into the seating surface 12, but instead of or in addition to this, the grooves 12a to 512a may be recessed into one or both axial end faces of the die 30. When recessed into both sides, the grooves 12a to 512a may be different from each other.

[0092] In the second embodiment, the winding direction of the groove 212a (spiral) may be the opposite to the winding direction described above. The winding direction toward the radially inner side of the seating surface 12 (the side toward the center axis of the seating surface 12) may be the reverse rotation direction of the die 30 (the opposite direction to the direction of arrow A).

[0093] In the third embodiment, the groove 312a is formed linearly, and in the fourth and fifth embodiments, the grooves 412a and 512a are formed arc-shaped, but other shapes may be used. Examples of other shapes include a zigzag shape (sawtooth shape) made up of a combination of straight lines, a zigzag shape (sine wave shape) made up of a combination of curved lines, and a shape that combines these.

[0094] In the above embodiments, the structure for fixing the axial support member 20 to the mounting hole 13 has been described as being pulled in by the pull-in bolt 40, but other fixing structures may be adopted. Examples of other fixing structures include a structure in which the axial support member 20 (shaft portion 21) is press-fitted into the mounting hole 13, and a structure in which a male screw threaded on the outer circumferential surface of the axial support member 20 (shaft portion 21) is threaded on the inner circumferential surface of the mounting hole 13 and fastened with a female screw.

[0095] Although not described in the above embodiments, wrapping or nitride coating may be applied to the seating surface 12 and the die 30 (axial end surfaces).

[0096] In each of the above embodiments, the restricting surface 122a of the restricting member 120 of the holder 100 is formed as a tapered surface. However, the restricting surface 122a may be a non-tapered surface (a peripheral surface parallel to the central axis of the restricting member 120).

[0097] In each of the above embodiments, the outer peripheral surface of the head 22 of the support member 20 is formed parallel to the central axis of the support member 20, but the outer peripheral surface of the head 22 may also be a tapered surface whose diameter becomes smaller as it moves away from the shaft portion 21.

[0098] In each of the above embodiments, a case has been described in which the thread 32 of the die 30 does not have a lead, and the support member 20 is arranged on the base 10 in a position inclined by the lead angle, but a structure in which the thread 32 of the die 30 has a lead, and the support member 20 is arranged on the base 10 in a vertical position, may also be used.

[0099] In each of the above embodiments, a structure has been described in which the male thread 112b of the holding member 110 (body portion 112) and the female thread 121a of the regulating member 120 (outer fitting portion 121) are screwed together, but the male thread 112b and the female thread 121a may be omitted. That is, the inner diameter of the outer fitting portion 121 may be set to a dimension equal to or slightly larger than the outer diameter of the body portion 112, the regulating member 120 may be made movable in the axial direction relative to the holding member 110, and the regulating member 120 may be fixed to the holding member 110 by a hexagon socket set screw fastened to the fastening hole 121c of the outer fitting portion 121.

[0100] In each of the above embodiments, the holder 100 is described as including the regulating member 120. However, the holder 100 may be configured without the regulating member 120. [Explanation of symbols]

[0101] 1 Rolling tools 10 Pedestal 11 Receiving hole 12 Seat 12a,212a,312a,412a,512a groove 20 Axle support member 30 Dice E1 end (radially outer end)

Claims

1. A rolling tool having a base having a receiving hole for receiving a workpiece, a plurality of support members disposed on the base, and a plurality of dies rotatably supported by the support members and disposed around the receiving hole of the base, A groove is formed in at least one of the seat surface of the base and the axial end surface of the die, A rolling tool characterized in that the groove is formed in a spiral shape, and the spiral direction as it moves radially inward is the rotation direction of the die.

2. A rolling tool having a base having a receiving hole for receiving a workpiece, a plurality of support members disposed on the base, and a plurality of dies rotatably supported on the support members and disposed around the receiving hole of the base, A groove is formed in at least one of the seat surface of the base and the axial end surface of the die, A rolling tool characterized in that the groove is formed extending radially, and the radially outer end of the groove is located radially outward of the outer edge of the axial end face of the die.

3. 3. The rolling tool according to claim 2, wherein the groove is curved in a convex shape toward the direction of rotation of the die.

4. 4. The rolling tool according to claim 2, wherein a groove width of the groove on a radially inner side is made larger than a groove width of the groove on a radially outer side.

5. 5. The rolling tool according to claim 2, wherein a groove depth of the groove on a radially inner side is made larger than a groove depth of the groove on a radially outer side.

6. A rolling tool having a base having a receiving hole for receiving a workpiece, a plurality of support members disposed on the base, and a plurality of dies rotatably supported on the support members and disposed around the receiving hole of the base, A groove is formed in at least one of the seat surface of the base and the axial end surface of the die, The groove is recessed in the seat surface of the base, A rolling tool characterized in that a groove width in a region of the support member opposite the receiving hole is made larger than a groove width in a region of the support member facing the receiving hole.

Images