Drilling device, transfer press machine, and method for manufacturing cylindrical workpiece with through-hole

Abstract

To provide a technique capable of punching multiple through holes in a tubular workpiece with higher accuracy in comparison to a conventional technique.SOLUTION: A punching device 40 according to the present disclosure includes multiple punches 57 and the multiple punches 57 include multiple pairs of punches 57 that are arranged on the same straight line with a tubular workpiece 90 held therebetween. The punching device is configured such that the multiple pairs of punches 57 punch through holes 92A two by two with staggered timing on the tubular workpiece 90 on which the multiple through holes 92A are not punched.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present disclosure relates to a drilling device that drills a plurality of through holes in a cylindrical workpiece from the side, a transfer press machine having such a drilling device, and a method for manufacturing a cylindrical workpiece with through holes. [Background technology]

[0002] A known conventional punching device is provided with a plurality of punches that surround a cylindrical workpiece, and the punches punch a plurality of through holes in the cylindrical workpiece at one time (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP-A-8-71992 (Paragraph

[0004] and Figure 2). Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional punching devices described above, variations in the lengths of the multiple punches and variations in the shapes of the power transmission components to the multiple punches can cause the actual punching timing of the multiple punches to be off, resulting in through holes being drilled in a state where the deformation of the cylindrical workpiece due to the loads received from the multiple punches is out of balance, resulting in reduced processing accuracy.In contrast, the present disclosure provides a technology that enables multiple through holes to be drilled in a cylindrical workpiece with higher accuracy than conventional technology. [Means for solving the problem]

[0005] A first aspect of the present disclosure is a drilling device that uses a plurality of punches surrounding a cylindrical workpiece to drill a plurality of through holes in the workpiece from the side, the plurality of punches including a plurality of pairs of punches arranged in the same straight line sandwiching the cylindrical workpiece, and configured such that for a cylindrical workpiece in which the plurality of through holes have not been drilled, the plurality of pairs of punches drill the through holes two at a time at staggered timing. [Effects of the Invention]

[0006] In the first aspect of the present disclosure, the punching device includes a plurality of punches surrounding a cylindrical workpiece, each pair of punches arranged on a straight line sandwiching the cylindrical workpiece. The punches drill two through holes at a time, staggering the timing of the punches, into a cylindrical workpiece that does not already have multiple through holes drilled. This minimizes the impact of variations in the length of the punches on the deformation of the cylindrical workpiece during drilling between the paired punches. Even if the timing of the punches is shifted, the paired punches are arranged on a straight line sandwiching the cylindrical workpiece, preventing the deformation of the cylindrical workpiece from becoming unbalanced during drilling. In other words, the technology disclosed herein allows multiple through holes to be drilled in a cylindrical workpiece with more balanced deformation than conventional methods, enabling the drilling of multiple through holes with higher accuracy than conventional methods. Furthermore, because multiple through holes are drilled two at a time, the processing time is reduced compared to when the timing of the punches is simply shifted. Furthermore, the transfer press and the method for manufacturing a cylindrical workpiece with a through hole according to the present disclosure also achieve the same effects as the drilling device of the first aspect. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a front view of a transfer press according to a first embodiment of the present disclosure. [Figure 2] Perspective view of a cylindrical workpiece [Figure 3] Perspective view of a drilling device [Figure 4] A cutaway perspective view of a drilling device [Figure 5] Side cross-sectional view of a drilling device [Figure 6] Side cross-sectional view of a drilling device [Figure 7] A cutaway perspective view of the lifting pipe, the cylindrical die, the cylindrical workpiece, and the upper base. [Figure 8] (A) Perspective view of the lifting pipe, (B) Perspective view of the lifting pipe [Figure 9] FIG. 1 is a side cross-sectional view of a drilling device with a slider positioned at a first slide position; [Figure 10] FIG. 1 is a side cross-sectional view of a drilling device with the slider positioned at a second slide position; [Figure 11] Side view of multiple cam protrusions [Figure 12] Enlarged cross-sectional view of the punch and part of the workpiece DETAILED DESCRIPTION OF THE INVENTION

[0008] [First embodiment] A transfer press 10 according to one embodiment of the present disclosure will be described with reference to FIGS. 1 to 12. As shown in FIG. 1, the transfer press 10 includes a plurality of support blocks 31 arranged in a row in the horizontal direction on a lower table 12. Some of the consecutively arranged support blocks 31 are provided with through holes extending vertically therethrough, and a plurality of dies 30 are provided within the through holes. Above the plurality of dies 30, a plurality of punches 20 corresponding to the dies 30 are supported by the ram 11. The punches 20 and dies 30 facing each other vertically form a plurality of processing stages ST1 for performing drawing or ironing, which are arranged at equal intervals in the horizontal middle portion of the transfer press 10.

[0009] Hereinafter, in the description of each part, as with the lateral direction of the entire transfer press 10, the horizontal direction in which the support blocks 31 are lined up will be referred to as the "lateral direction H1," and the horizontal direction perpendicular to the lateral direction H1 will be referred to as the "front-rear direction H2." The side shown in FIG. 1 will be referred to as the "front side," and the opposite side will be referred to as the "rear side." Furthermore, the spacing between the multiple punches 20 and the multiple dies 30 will be referred to as the "specific pitch."

[0010] The entire upper surface of the multiple support blocks 31 forms a workpiece transport surface 19, and a transfer device 14, a transport device that intermittently transports workpieces at a specific pitch, is provided on the workpiece transport surface 19. The transfer device 14 has a pair of rails 15 that extend in a lateral direction H1 and face each other in a front-to-rear direction H2 (only the front rail 15 is shown in FIG. 1). The pair of rails 15 are supported on a common slide support base (not shown) so that they can move toward and away from each other in the facing direction (front-to-rear direction H2). The slide support base is supported so that they can move back and forth in the lateral direction H1. That is, the pair of rails 15 are supported so that they can move back and forth in the lateral direction H1 while maintaining their opposing state. Furthermore, multiple fingers 16 are arranged on the facing surfaces of the pair of rails 15 at a specific pitch in the lateral direction H1.

[0011] The transfer device 14 shares a drive source with the ram 11. Specifically, a main camshaft (not shown) for raising and lowering the ram 11 is provided at the top of the transfer press 10, extending in the horizontal direction H1. A sub-camshaft 89 (see FIG. 3) for raising and lowering a knockout pin (not shown) for pushing a workpiece upward from the die 30 is provided at the bottom of the transfer press 10, extending in the horizontal direction H1. Furthermore, a side shaft (not shown) extending vertically and having its upper and lower ends connected to the left ends of the main camshaft and the sub-camshaft 89 by gears is provided on the left side of the transfer press 10 when viewed from the front. Furthermore, a rotation output of a main motor (not shown), which serves as a drive source, is connected to the right end of the main camshaft. The side shaft is provided with a cam for reciprocating the slide support base in the horizontal direction H1 at a specific pitch. The pair of rails 15 are moved toward and away from each other by an air cylinder (not shown).

[0012] The movement of each pair of fingers 16 to the left in Figure 1 is referred to as "rearward," and the movement to the opposite side is referred to as "forward," with the left end of a specific pitch referred to as the "rear end position" and the right end of a specific pitch referred to as the "front end position." The pair of rails 15 then move from a spaced apart state at the rear end position toward each other to become a close-up state, move in that close-up state to the front end position, then move away from each other to become a spaced apart state, and then move in that spaced apart state to the rear end position, repeating this cyclical operation.

[0013] A work supply device 13 is provided between the ram 11 and the lower base 12, in an area to the left of the multiple processing stages ST1 when viewed from the front. The work supply device 13 includes a platform 13K that straddles the transfer device 14 in the front-to-rear direction H2. A composite die (not shown) consisting of a punching die and a forming die is supported on the platform 13K in a raised portion above the work transport surface 19. The ram 11 also supports a composite punch 21 that corresponds to the composite die. The composite punch 21 has a shaping punch 21B inside a cylindrical punching punch 21A. A disk-shaped blank material is punched out of a plate material (not shown) fed from the rear of the work supply device 13 by the punching punch 21A and the punching die. The blank material is then formed into a cylindrical workpiece with a bottomed bottom and an open top by the forming punch 21B and the forming die, and the blank is then pushed down to the work transport surface 19.

[0014] Hereinafter, when distinguishing between the multiple pairs of fingers 16, they will be referred to as the first, second, third, etc. fingers 16 going from left to right in Fig. 1. The first pair of fingers 16 is disposed at the rear end position when the work supply device 13 pushes the work down to the work transfer surface 19, and clamps the work by moving from a separated state to a close state. Then, each time the ram 11 moves up and down, the work is transferred to the second, third, etc. fingers 16 in sequence, and is transferred to the right side in Fig. 1 (hereinafter referred to as the "downstream side" where appropriate) at specific pitches, and is drawn or ironed in the multiple processing stages ST1.

[0015] More specifically, the composite die of the workpiece supply device 13 and the die 30 of the front machining stage ST1, which is closest to it, are separated by, for example, two specific pitches. The central position between them is a so-called dummy stage ST2, where workpieces are temporarily loaded and unloaded without being processed. The first finger 16 receives the workpiece at its rear end position and moves forward to load it onto the dummy stage ST2. The support block 31 of the dummy stage ST2 has a workpiece suction hole (not shown) that opens onto the workpiece transfer surface 19, to which a suction pump is connected via an on-off valve. The workpiece is then loaded onto the dummy stage ST2 while being clamped by the first finger 16 and positioned directly above the workpiece suction hole. The on-off valve is then opened, and the workpiece is fixed on the workpiece transfer surface 19 by negative pressure. The second finger 16 then retreats and moves to the dummy stage ST2 to clamp the workpiece. Then, the on / off valve is closed, allowing the workpiece to move on the workpiece transfer surface 19, and the second finger 16 moves forward to carry the workpiece into the leading processing stage ST1.

[0016] At the first processing stage ST1, the workpiece is pushed by the punch 20 into the die 30 below the workpiece conveying surface 19, whereby it is released from the second finger 16. Thereafter, the workpiece is pushed up from the die 30 onto the workpiece conveying surface 19 by a knockout pin (not shown) powered by the sub-camshaft 89, and is then clamped by the third finger 16 located at the rear end position. In the same manner, the workpiece is conveyed successively to the plurality of processing stages ST1 and is drawn or ironed to be formed into a cylindrical workpiece 90 (see FIG. 2).

[0017] A drilling device 40 is provided in an area between the ram 11 and the lower table 12, to the right of the multiple processing stages ST1 when viewed from the front. The drilling device 40 drills multiple through holes 91A, 92A (see FIG. 2) from the side of the cylindrical workpiece 90 that has passed through the multiple processing stages ST1. In addition, first and second reversing dummy stages ST3, for example, are provided between the processing stage ST1 at the downstream end and the drilling device 40. The cylindrical workpiece 90 that has passed through the multiple processing stages ST1 is then turned upside down by the first and second reversing dummy stages ST3, as will be described below, and is supplied to the drilling device 40 with the opening 90K (see FIG. 2) facing downward.

[0018] Of the multiple fingers 16 described above, the finger 16 (hereinafter referred to as the "reversing finger 16") that reciprocates between the first and second reversing dummy stages ST3 rotates 180 degrees while moving in the horizontal direction H1. Specifically, below the pair of reversing fingers 16, a pair of racks 16A extending in the horizontal direction H1 are fixed to the support block 31, and a pair of gears 16B (only one of the racks 16A and the gear 16B is shown in FIG. 1) that mesh with the pair of racks 16A are rotatably supported by the pair of rails 15. The pair of reversing fingers 16 are slidably supported in the front-rear direction H2 by the pair of gears 16B and are biased in directions toward each other. As a result, the pair of reversing fingers 16 rotate together with the pair of gears 16B as the pair of rails 15 move in the lateral direction H1, and their posture changes by 180 degrees between when they are positioned on the first reversing dummy stage ST3 and when they are positioned on the second reversing dummy stage ST3.

[0019] Similarly to the dummy stage ST2, the first and second inversion dummy stages ST3 are provided with first and second workpiece suction holes (not shown), each of which is connected to a suction pump via an on-off valve. When the cylindrical workpiece 90 is carried into the first inversion dummy stage ST3 by a finger 16 upstream of the inversion finger 16 (hereinafter referred to as a "general finger 16" when distinguished from the inversion finger 16) with the opening 90K facing upward, the on-off valve for the first suction hole opens, fixing the cylindrical workpiece 90 on the workpiece conveying surface 19. Thereafter, the inversion finger 16 retreats and moves to the first inversion dummy stage ST3, where it clamps the cylindrical workpiece 90. Thereafter, the on / off valve for the first suction hole is closed, allowing the cylindrical workpiece 90 to move on the workpiece conveying surface 19, and the inversion fingers 16 rotate and move forward to load the cylindrical workpiece 90 onto the second inversion dummy stage ST3 with the opening 90K facing downward. Then, the on / off valve for the second suction hole is opened, fixing the cylindrical workpiece 90 on the workpiece conveying surface 19. After that, when the general fingers 16 downstream of the inversion fingers 16 clamp the cylindrical workpiece 90 on the second inversion dummy stage ST3, the on / off valve for the second suction hole is closed, allowing the cylindrical workpiece 90 to move on the workpiece conveying surface 19, and the general fingers 16 load the cylindrical workpiece 90 into the drilling device 40 adjacent to the second inversion dummy stage ST3. In this manner, in this embodiment, the inversion device 18 that inverts the cylindrical workpiece 90 is configured using a part of the transfer device 14, suction holes, etc.

[0020] FIG. 2 shows the cylindrical workpiece 90 with the opening 90K facing downward. As shown in the figure, the cylindrical workpiece 90 has a cylindrical shape that tapers from the open end having the opening 90K toward the closed end on the opposite side. Specifically, a tapered portion 94 is provided near the open end in the axial direction of the cylindrical workpiece 90, and a stepped portion 95 perpendicular to the axial direction is provided at a position farther from the open end than the tapered portion 94. The tapered portion 94 and the stepped portion 95 divide the cylindrical workpiece 90 into first to third cylindrical portions 91, 92, and 93 arranged in order from the closed end side. The diameter of the second cylindrical portion 92 is slightly smaller than the diameter of the third cylindrical portion 93, and the diameter of the first cylindrical portion 91 on the closed end side is smaller than the diameter of the second cylindrical portion 92 by a larger difference than the difference between the diameters. The drilling device 40 drills a plurality of through holes 91A at a plurality of circumferential positions near the end portion on the closed end side of the first cylindrical portion 91, and drills a plurality of through holes 92A at a plurality of circumferential positions near the end portion on the closed end side of the second cylindrical portion 92. More specifically, the plurality of through holes 91A penetrate the first cylindrical portion 91 in the radial direction at positions that divide the first cylindrical portion 91 into thirds in the circumferential direction, and the plurality of through holes 92A penetrate the second cylindrical portion 92 in the radial direction at positions that divide the second cylindrical portion 92 into sixths in the circumferential direction. When the cylindrical workpiece 90 is seen through from above, each through hole 91A is arranged so as to be located in the center of a pair of adjacent through holes 92A.

[0021] 4, the drilling device 40 includes a pair of support members 41 that stand upright from the workpiece conveying surface 19 and face each other across the transfer device 14 (see FIG. 1) in the front-to-rear direction H2, and an upper base 42 that is supported from below by the support members 41. As a result, the upper base 42 is disposed above a workpiece conveying space 40V in which the cylindrical workpiece 90 is conveyed by the transfer device 14. Specifically, the pair of support members 41 are block-shaped, and the front support member 41 stands upright from the front end of the upper surface of the support block 31 adjacent to the second reversing dummy stage ST3 (see FIG. 1), and the other support member 41 stands upright from a fixed plate 31P that presses down on a stepped portion 31D on the rear surface of the support block 31 from above.

[0022] As shown in Fig. 4, the upper base 42 includes a base body 43 supported from below by a pair of support members 41, and a core portion 44 and a core holder 45 supported by the base body 43. As shown in Fig. 3, the base body 43 has a shape such as a rectangular thick plate that is long in the front-rear direction H2, with both front and rear ends cut to narrow in a stepped manner. Furthermore, as shown in Fig. 4, both narrow ends have their undersides hollowed out and are supported from below by the pair of support members 41 mentioned above.

[0023] As shown in FIG. 5, a core accommodating hole 43A is provided in the center of the base body 43, penetrating vertically. The upper portion of the core accommodating hole 43A has a stepped diameter. As shown in FIG. 3, the base body 43 is formed with a plurality of first grooves 48 and a plurality of second grooves 49 that extend radially from the core accommodating hole 43A. The plurality of first grooves 48 are arranged so as to divide the circumference of the core accommodating hole 43A into, for example, three equal parts, and the plurality of second grooves 49 are arranged so as to divide the circumference of the core accommodating hole 43A into, for example, six equal parts. Each of the plurality of first grooves 48 is arranged at the center of a pair of adjacent second grooves 49.

[0024] The first grooves 48 and second grooves 49 are both rectangular grooves with a rectangular cross section, and their interiors have the following structure. As shown in FIGS. 5 and 6, the first grooves 48 and second grooves 49 each have an upwardly facing stepped surface 47D at the end away from the core accommodating hole 43A, and the portion below the stepped surface 47D is shorter than the portion above. The portion below the stepped surface 47D of each of the first grooves 48 and second grooves 49 forms a slider accommodating section 47A, and a guide hole 43G opens into the bottom surface of the slider accommodating section 47A. The guide hole 43G has a rectangular cross section, extends vertically, and has a pair of inner surfaces facing each other in the longitudinal direction of the slider accommodating section 47A and a pair of inner surfaces facing each other in a direction perpendicular to the above. The upper portion of the inner surface of the guide hole 43G facing the core accommodating hole 43A is inclined toward the core accommodating hole 43A. Furthermore, the upper opening of the guide hole 43G is disposed at approximately the center in the width direction and the length direction of the bottom surface of the slider accommodating portion 47A.

[0025] A plate-shaped sliding metal 47M having a through hole overlapping with the guide hole 43G is laid on the bottom surface of the slider accommodating portion 47A, and the slider 50 is accommodated on the sliding metal 47M. The slider 50 is a rectangular column with an overall length shorter than that of the slider accommodating portion 47A and approximately the same width as the slider accommodating portion 47A. The upper surface of the slider accommodating portion 47A is a flat surface that is flush with the step surface 47D.

[0026] A cam hole 51 is provided in the middle of the slider 50 in the longitudinal direction, penetrating it vertically. The cam hole 51 has a rectangular cross section and a pair of cam surfaces, which are a pair of inner surfaces facing each other in the longitudinal direction of the slider 50. The cam surface on the core accommodating hole 43A side has a substantially lower half that forms a vertical surface 51A parallel to the vertical direction, while a substantially upper half that forms a first inclined surface 51B inclined toward the core accommodating hole 43A. Conversely, the cam surface on the side away from the core accommodating hole 43A has a substantially upper half that forms a vertical surface 51A parallel to the vertical direction, while a substantially lower half that forms a second inclined surface 51C inclined toward the core accommodating hole 43A. The first and second inclined surfaces 51B, 51C are parallel to each other, and the lower end of the first inclined surface 51B is located slightly below the upper end of the second inclined surface 51C.

[0027] An engagement groove 52 is formed in the end of the slider 50 on the core accommodating hole 43A side. The engagement groove 52 extends in the longitudinal direction of the slider 50 and opens to the bottom surface and end surface of the slider 50. The half of the engagement groove 52 on the core accommodating hole 43A side is narrower and shallower than the other half. The base end of a punch 57, which will be described later, engages with the engagement groove 52 and extends from the slider 50 toward the core accommodating hole 43A.

[0028] The portions of each of the first grooves 48 and second grooves 49 above the step surface 47D form block accommodating portions 47B, which accommodate a guide block 53. The guide block 53 has approximately the same width as the block accommodating portions 47B and is longer than the slider 50. One end of the guide block 53 is placed on the step surface 47D and fixed with a bolt B. The other end of the guide block 53 is placed from above on a flange 45F of the core presser 45, which will be described in detail later.

[0029] A guide hole 53G is formed in the guide block 53 at a position closer to the core accommodating hole 43A. The guide hole 53G has a rectangular cross section, and all four inner surfaces of the guide hole 53G except for the inner surface on the core accommodating hole 43A side are located directly above the opening of the guide hole 43G described above.

[0030] A threaded hole penetrating vertically is formed in the guide block 53 on the side farther from the core accommodating hole 43A than the guide hole 53G, and a ball plunger 53P is attached to the threaded hole. When the slider 50 is placed in the first sliding position, the ball of the ball plunger 53P engages with a recess 50P formed in the upper surface of the slider 50.

[0031] The internal structures of the first groove 48 and the second groove 49 are common in the above-mentioned respects but differ in the following respects. That is, the slider accommodating portion 47A of the second groove 49 is located lower in the base body 43 than the slider accommodating portion 47A of the first groove 48, and the block accommodating portion 47B of the second groove 49 is deeper than the block accommodating portion 47B of the first groove 48 by the difference in their positions. As shown in FIG. 6 , in the second groove 49, the entire guide hole 53G is accommodated in the block accommodating portion 47B, and part of the upper surface of the guide hole 53G is covered by the flange 45F of the core presser 45. Meanwhile, as shown in FIG. 5 , in the first groove 48, only part of the guide hole 53G in the up-down direction is accommodated in the block accommodating portion 47B, and a stepped surface 53D provided at the end of the guide block 53 is covered by the flange 45F of the core presser 45.

[0032] 5, the core portion 44 has a flange 44F at its upper end, and is fitted into the core accommodating hole 43A from above, with the flange 44F abutting against the stepped surface at the top of the core accommodating hole 43A. The flange 45F of the core holder 45 covers the core portion 44 and the opening edge of the core accommodating hole 43A from above, and is screwed to the base body 43 and the core portion 44, thereby integrating the base body 43, the core portion 44, and the core holder 45.

[0033] As shown in FIG. 7, the core portion 44 is provided with a workpiece receiving portion 46 capable of receiving a cylindrical workpiece 90 from below. The workpiece receiving portion 46 is a recessed portion that opens downward and tapers upward. Specifically, a lower surface protrusion 44A hangs down from the center of the lower surface of the core portion 44 and protrudes downward from the lower surface of the base body 43 (see FIG. 4). The workpiece receiving portion 46 is formed from the lower end of the lower surface protrusion 44A to a position near the upper surface of the core portion 44. The workpiece receiving portion 46 also has a stepped surface 46D formed midway in the vertical direction, and a tapered surface 46E formed below that, with the diameter tapering upward. A pair of notches 46G are formed at two opposing locations on the lower end of the lower surface protrusion 44A in the horizontal direction H1 to avoid interference with the cylindrical workpiece 90 being transported by the transfer device 14 (only the left notch 46G in the horizontal direction H1 is shown in FIG. 7).

[0034] The core portion 44 is provided with a plurality of first punch holes 54 (see FIG. 5) extending radially from the upper end of the work receiving portion 46, and a plurality of second punch holes 55 (see FIG. 6) extending radially from an intermediate portion of the work receiving portion 46 between the stepped surface 46D and the tapered surface 46E. As shown in FIG. 5, the plurality of first punch holes 54 are aligned in a straight line with the plurality of sliders 50 in the plurality of first grooves 48, and as shown in FIG. 6, the plurality of second punch holes 55 are aligned in a straight line with the plurality of sliders 50 in the plurality of second grooves 49. 5 and 6, the first punch hole 54 and the second punch hole 55 include a first guide portion 56A that extends with a uniform inner diameter from the outer surface of the core portion 44 to a first position closer to the work receiving portion 46, a reduced diameter portion 56B that reduces in diameter from the first position toward a second position further closer to the work receiving portion 46, and a second guide portion 56C that extends with a uniform inner diameter from the second position to the inner surface of the work receiving portion 46. A punch 57 is supported in each of the plurality of first punch holes 54 and second punch holes 55.

[0035] As shown in FIG. 6 , each punch 57 includes a round-bar-shaped support shaft portion 57A, a flange 57F extending laterally from the base end of the support shaft portion 57A, and a punch body 57B extending from the center of the tip surface of the support shaft portion 57A and having a smaller outer diameter than the support shaft portion 57A. The support shaft portion 57A is fitted into the first guide portion 56A, and the punch body 57B is fitted into the second guide portion 56C. The base end of the punch 57, including the flange 57F, is received from below in the engagement groove 52 of the slider 50, engaging the punch 57 so that it slides integrally with the slider 50. When the slider 50 is positioned in the first slide position, the tip of the punch body 57B is positioned within the second guide portion 56C and does not protrude into the workpiece receiving portion 46. When the slider 50 is positioned in the second slide position, the punch body 57B protrudes into the workpiece receiving portion 46.

[0036] 5, an upper surface recess 44B is formed in the center of the upper surface of the core portion 44. A plurality of (e.g., three) pin holes 46L penetrate between the bottom surface of the upper surface recess 44B and a step surface 46D in the work receiving portion 46, at positions that avoid the plurality of first punch holes 54. The core presser 45 is also provided with a support sleeve 45C that is closed at its upper end and open at its lower end, and the lower end of the support sleeve 45C fits into the upper surface recess 44B of the core portion 44. The aforementioned flange 45F protrudes laterally from a position near the lower end of the support sleeve 45C.

[0037] A pin support member 58 is housed inside the support sleeve 45C and is movable up and down. The pin support member 58 has a shaft 58B standing upright from the center of a main body 58A that fits snugly inside the support sleeve 45C. Multiple knockout pins 58P are fixed to the main body 58A, extend downward from the main body 58A, and are inserted into multiple pin holes 46L. The shaft 58B protrudes upward from the support sleeve 45C through a through-hole formed in the center of the top wall of the support sleeve 45C. A cylindrical elastic sleeve 59A is fitted around the shaft 58B, and a compression coil spring 59B is fitted around the elastic sleeve 59A. The pin support member 58 is biased to its lower end position by the resilience of the compression coil spring 59B, and the upper end of the elastic sleeve 59A is positioned below the top wall of the support sleeve 45C. When the pin support member 58 is positioned at the lower end position, the lower ends of the multiple knockout pins 58P protrude downward from the step surface 46D of the work receiving portion 46, and when the lower ends of the multiple knockout pins 58P are pushed to a position where they retract above the step surface 46D, just before that, the elastic sleeve 59A abuts against the ceiling wall of the support sleeve 45C and is compressed and deformed.

[0038] 7, an elevation pipe 80 is provided coaxially below the workpiece receiving section 46, and a cylindrical die 70 is provided at the upper end of the elevation pipe 80. The cylindrical die 70 emerges above the workpiece conveying surface 19 from a through-hole 31H that passes vertically through the support block 31, plunges into the cylindrical workpiece 90 held between the pair of fingers 16, and then rises to push the cylindrical workpiece 90 into the workpiece receiving section 46.

[0039] The cylindrical die 70, like the cylindrical workpiece 90, has a step 70D at an axial midpoint, and has a first cylindrical portion 71 above the step 70D and a second cylindrical portion 72 below the step 70D. The first cylindrical portion 71 is sized to fit snugly inside the first cylindrical portion 91 of the cylindrical workpiece 90, while the second cylindrical portion 72 is sized to fit snugly inside the second cylindrical portion 92 of the cylindrical workpiece 90. The upper end of the first cylindrical portion 71 is open, and a plurality of first punching holes 71A corresponding to the plurality of first punch holes 54 in the upper base 42 (more specifically, the core portion 44) are formed at multiple circumferential positions on the upper end of the first cylindrical portion 71 so as to penetrate radially. The step 70D also has relief holes 70E formed at multiple circumferential positions so as to penetrate vertically. A plurality of second punched holes 72A corresponding to the plurality of second punched holes 55 of the upper base 42 are formed at a plurality of circumferential positions on the upper end of the second cylindrical portion 72 so as to penetrate radially between the outer surface of the second cylindrical portion 72 and the inner surface of the relief hole 70E. At a position where the step portion 95 of the cylindrical workpiece 90 is sandwiched from above and below between the step portion 70D of the cylindrical die 70 and the step surface 46D of the workpiece receiving portion 46 (hereinafter referred to as the "push-in completion position"), the corresponding first punched holes 71A and the corresponding first punched holes 54 are aligned coaxially, and the corresponding second punched holes 72A and the corresponding second punched holes 55 are aligned coaxially.

[0040] A positioning hole 72Z is ​​formed in the axial midpoint of the second cylindrical portion 72, and a positioning hole 42Z is ​​formed in the upper base 42 so as to be coaxially aligned with the positioning hole 72Z when the cylindrical die 70 is positioned at the push-in completion position. The cylindrical die 70 can be positioned at the push-in completion position by inserting a positioning pin inserted from the side into the positioning hole 42Z of the upper base 42 into the positioning hole 72Z of the cylindrical die 70. This makes it easy to adjust the relative positions of the upper base 42 and the cylindrical die 70.

[0041] The cylindrical die 70 is movably supported at the upper end of the lifting pipe 80 by the following structure. As shown in Figure 8, the lifting pipe 80 includes a pipe member 81, and a base sleeve 82 and a guide sleeve 83 fixed to the upper end of the pipe member 81.

[0042] The base sleeve 82 is thicker than the pipe member 81, and a central hole 82A that penetrates the inside of the base sleeve 82 from top to bottom has stepped surfaces at two locations in the vertical direction. The diameter of the base sleeve 82 is expanded in a stepped manner above and below the central portion in the vertical direction, and the pipe member 81 is fitted and fixed inside the expanded diameter portion on the lower side. In addition, an elastic sleeve 84, which is, for example, a cylindrical elastic body, is fitted inside the upper expanded diameter portion of the central hole 82A and protrudes upward from the base sleeve 82. The inner surfaces of the central portion of the center hole 82A, the inner surfaces of the elastic sleeve 84, and the inner surface of the pipe member 81 are generally flush with each other.

[0043] The guide sleeve 83 has a flange 83F at its lower end, and this flange 83F is overlapped and fixed to a flange 82F that protrudes laterally from the upper end of the base sleeve 82. A center hole 83A that passes vertically through the inside of the guide sleeve 83 is a circular hole with a larger diameter than the center hole 82A of the base sleeve 82, with two flat surfaces on its inner periphery. An annular protrusion 83E protrudes inward from the upper end of the inner surface of the center hole 82A, and the inside of this annular protrusion 83E forms a circular hole 83J. A sliding sleeve 83S is fitted into this circular hole 83J, and a flange 83T that protrudes laterally from the lower end of the sliding sleeve 83S overlaps the annular protrusion 83E from below. The flange 83T has the same cross-sectional shape as the center hole 83A of the guide sleeve 83.

[0044] A flange 70F having the same planar cross-sectional shape as the central hole 83A of the guide sleeve 83 projects from the lower end of the second cylindrical portion 72 of the cylindrical die 70. The second cylindrical portion 72 penetrates the inside of the sliding sleeve 83S, and the flange 70F is fitted into the guide sleeve 83. The upper end of the elastic sleeve 84 abuts against the edge of the opening in the lower surface of the cylindrical die 70. Furthermore, a compression coil spring 85 is fitted on the outside of the elastic sleeve 84 inside the guide sleeve 83, and the compression coil spring 85 is tensioned between the upper surface of the base sleeve 82 and the lower surface of the cylindrical die 70. As a result, the cylindrical die 70 is supported on the upper part of the elevating pipe 80 so as to be vertically movable while its rotation around the central axis is restricted, and is biased to the upper end position of its movable range.

[0045] A pair of flat surfaces 80A is formed at two circumferential locations on the outer peripheral surface of the upper end of the lift pipe 80. The pair of flat surfaces 80A is formed from the upper end of the guide sleeve 83 to a vertically intermediate position of the base sleeve 82 and is arranged to face each other in the front-to-rear direction H2. Meanwhile, the through hole 31H of the support block 31 has a rectangular cross-section above the vertically intermediate position and a circular cross-section below the vertically intermediate position. The portion of the lift pipe 80 above the vertically intermediate position of the base sleeve 82 is fitted into the rectangular hole portion of the through hole 31H, and the pair of flat surfaces 80A overlaps with the pair of inner surfaces of the rectangular hole portion, restricting rotation of the lift pipe 80. Furthermore, the base sleeve 82 is fitted into the circular hole portion of the through hole 31H, thereby centering the lift pipe 80 with respect to the workpiece receiving portion 46.

[0046] The lift pipe 80 receives power from the sub-camshaft 89 and moves up and down in synchronization with the ram 11 and the transfer device 14. Specifically, as shown in Fig. 3, the lift pipe 80 is located forward of the sub-camshaft 89, and the pipe member 81 included in the lift pipe 80 extends to the same height as the sub-camshaft 89 or below. A guide sleeve 12B fixed via a bracket 12A to the underside of the base 12 (omitted in Fig. 3; see Fig. 1) supports a longitudinal midsection of the pipe member 81 so as to be slidable up and down.

[0047] A relay lever 88 is connected to a position near the lower end of the pipe member 81. The relay lever 88 is supported by a lever support base 12C fixed to the lower base 12 so as to rotate around a rotation fulcrum 88A that is diagonally above and behind the sub camshaft 89. The relay lever 88 is connected to the tip of the portion of the relay lever 88 that extends forward from the rotation fulcrum 88A so as to be rotatable around a rotation axis that is parallel to the sub camshaft 89. The pipe member 81 is clamped to the relay lever 88, and as described above, the relay lever 88 is connected to the pipe member 81.

[0048] A roller (not shown) is attached to the relay lever 88 between the connecting portion with the lift pipe 80 and the rotation fulcrum 88A, and this roller abuts from above against a cam 89A of the sub-camshaft 89. Furthermore, for example, a tension coil spring 12E (not shown) is hung between the tip of the portion of the relay lever 88 that extends rearward from the rotation fulcrum 88A and a bracket 12D that extends rearward from the lever support base 12C, and the roller is pressed against the cam 89A by the resilience of the spring.

[0049] As a result, as described above, the lifting pipe 80 receives power from the sub-camshaft 89 and moves up and down in synchronization with the ram 11 and the transfer device 14. Then, when the cylindrical workpiece 90 is carried into the workpiece standby position directly below the workpiece receiving section 46 while being held between the pair of fingers 16 of the transfer device 14, the lifting pipe 80 rises and the cylindrical die 70 at its upper end fits inside the cylindrical workpiece 90. Then, the cylindrical workpiece 90 is pushed upward by the cylindrical die 70 fitted inside it, detaches from the pair of fingers 16, and is pushed into the workpiece receiving section 46. At this time, the multiple knockout pins 58P protruding from the stepped surface 46D of the workpiece receiving portion 46 are pushed up by the stepped portion 95 of the cylindrical workpiece 90, and the stepped portion 95 of the cylindrical workpiece 90 is sandwiched between the stepped portion 70D of the cylindrical die 70 and the stepped surface 46D of the workpiece receiving portion 46, and the cylindrical die 70 is positioned at the pushing completion position. Then, as will be described later, the punch 57 of the punching device 40 is driven to punch through holes 91A, 92A in the cylindrical workpiece 90, and the punched pieces generated at this time are discharged below the transfer press machine 10 through the lifting pipe 80.

[0050] In addition, a branch passage may be provided in the pipe member 81 that branches off diagonally downward from a position near the lower end, and a suction pump may be connected to the branch passage, thereby creating a negative pressure inside the cylindrical die 70 and allowing the punched pieces to flow smoothly downward inside the lifting pipe 80.

[0051] 3 is attached to the ram 11 at a position above the upper base 42. The lifting base 60 has a main body 60H fixed to the ram 11 and a plurality of cam protrusions 61 protruding from the underside of the main body 60H.

[0052] The main body 60H has a flange 60F that projects laterally from the lower end of a square cylindrical center sleeve 60K. As shown in Figure 9, the center sleeve 60K is positioned directly above the support sleeve 45C of the upper base 42, and as shown in Figure 10, when the ram 11 is lowered, the support sleeve 45C is received inside the center sleeve 60K.

[0053] As shown in Figure 3, the multiple cam protrusions 61 correspond to the aforementioned multiple sliders 50 of the upper base 42, and extend vertically downward from a position on the underside of the flange 60F directly above the guide holes 53G of the multiple guide blocks 53, and as shown in Figure 9, the lower part has a crank-shaped bend toward the side away from the center sleeve 60K.

[0054] Specifically, each cam protrusion 61 has the same cross-sectional shape as the guide hole 53G. The lower end and a position near the lower end of the plate hanging down from the main body 60H are cut into a trapezoidal shape from the center sleeve 60K side and the opposite side, resulting in the aforementioned crank-like bent shape. As shown in FIG. 9 , the cam protrusion 61 has a first inclined surface 61B facing diagonally downward on the center sleeve 60K side, and a second inclined surface 61C facing diagonally upward on the opposite side from the center sleeve 60K. The first and second inclined surfaces 61B, 61C are positioned at the same vertical position and are parallel to each other. Furthermore, the upper and lower sides of the first and second inclined surfaces 61B, 61C of the cam protrusion 61 form vertical surfaces 61A that are parallel to the vertical direction.

[0055] The vertical movement of the cam protrusion 61 accompanying the lifting and lowering of the ram 11 is converted into horizontal sliding movement of the slider 50 as follows. As shown in FIG. 9 , when the cam protrusion 61 is separated, the slider 50 is disposed at the first slide position described above, which is the farthest from the workpiece receiving portion 46 within its movable range, and is held at that first slide position by the engagement between the ball plunger 53P and the recess 50P described above. In this state, the cam protrusion 61 descends and passes through the guide hole 53G of the guide block 53 and enters the cam hole 51 of each slider 50. Then, when the lower end of the second inclined surface 61C of the cam protrusion 61 is positioned below the upper end of the second inclined surface 51C of the slider 50 and the lower end of the cam protrusion 61 enters the guide hole 43G, the first inclined surface 61B of the cam protrusion 61 abuts against the first inclined surface 51B of the slider 50. As the cam protrusion 61 further descends, the slider 50 advances toward the workpiece receiving portion 46 together with the punch 57 due to sliding contact between the first inclined surfaces 51B, 61B, and the punch 57 cooperates with the cylindrical die 70 to punch out a portion of the cylindrical workpiece 90. Furthermore, as the cam protrusion 61 further descends, as shown in FIG. 10 , the cam protrusion 61 reaches the bottom dead center when the vertical surface 61A of the cam protrusion 61 above the first inclined surface 61B overlaps with the vertical surface 51A of the slider 50 below the first inclined surface 51B, and the slider 50 reaches the second slide position. At this time, the tip surface of the punch 57 reaches the inner surface of the cylindrical die 70, and the punched piece released from the cylindrical workpiece 90 is discharged into the lifting pipe 80.

[0056] On the other hand, when the cam projection 61 rises, the second inclined surface 61C of the cam projection 61 comes into sliding contact with the second inclined surface 51C of the slider 50, and the slider 50 then retreats away from the workpiece receiving portion 46. Then, when the second inclined surface 61C of the cam projection 61 passes over the second inclined surface 51C of the slider 50 and the vertical surface 61A of the cam projection 61 below the second inclined surface 61C overlaps with the vertical surface 51A above the second inclined surface 51C of the slider 50, the slider 50 returns to the first slide position, and the ball plunger 53P and the recess 50P engage with each other. Then, the cam projection 61 moves away from the slider 50 upward.

[0057] As described above, the first and second inclined surfaces 51B, 51C, 61B, 61C serve as sliding contact portions between the slider 50 and the cam protrusion 61, and the multiple punches 57 slide together with the multiple sliders 50 of the support base 42, thereby drilling multiple through holes 91A, 92A in the cylindrical workpiece 90.

[0058] The drilling device 40 of this embodiment is configured to drill a plurality of through holes 91A, 92A at staggered timings as follows. That is, the drilling device 40 is configured to first drill three pairs of six through holes 92A (hereinafter referred to as "second group of through holes 92A") arranged in the second cylindrical portion 92 (see FIG. 2) of the cylindrical workpiece 90, two at a time, in three separate runs, with staggered timings for each pair, and then drill the first through hole 91A of three through holes 91A (hereinafter referred to as "first group of through holes 91A") arranged in the first cylindrical portion 91 of the cylindrical workpiece 90 at the same timing as the timing for drilling the last pair of through holes 92A, and then sequentially drill the second and third through holes 91A with staggered timings. A more specific configuration will be described below with reference to FIG. 11.

[0059] 11 shows differences in the vertical positions of the first inclined surfaces 61B of the multiple cam protrusions 61 when the first inclined surfaces 51B (see FIGS. 5 and 6) of all sliders 50 are arranged at the same vertical position. In addition, in FIG. 11, the cam protrusions 61 are labeled with the suffixes U1 to U3 and V1 to V3 to distinguish them from one another. In the following description, the suffixes U1 to U3 and V1 to V3 will be used only when distinguishing between the cam protrusions 61.

[0060] In Fig. 11, three cam protrusions 61U1, 61U2, 61U3 suffixed with symbols U1 to U3 are cam protrusions 61 for driving three punches 57 for punching the plurality of through holes 91A in the first group described above. On the other hand, cam protrusions 61V1, 61V2, 61V3 suffixed with symbols V1 to V3 are cam protrusions 61 for driving three pairs of six punches 57 for punching the plurality of through holes 92A in the second group described above, and since the pairs of cam protrusions 61 constituting each pair have the same configuration, only one cam protrusion 61V1, 61V2, 61V3 of each pair is shown in Fig. 11.

[0061] As shown in the same figure, the first inclined surface 61B of the cam protrusion 61V1 of the first pair of cam protrusions 61V1 to V3 of the second group is located lower than the first inclined surface 61B of the cam protrusion 61V2 of the second pair by a height difference L2, and the first inclined surface 61B of the cam protrusion 61V2 of the second pair is located lower than the first inclined surface 61B of the cam protrusion 61V3 of the third pair by a height difference L2.

[0062] Furthermore, the first inclined surface 61B of the first cam protrusion 61U1 of the first group of cam protrusions 61U1-U3 is located at the same height as the first inclined surface 61B of the third pair of cam protrusions 61V3 of the second group. The first inclined surface 61B of the first cam protrusion 61U1 is located lower than the first inclined surface 61B of the second cam protrusion 61U2 by a height difference L3, and the first inclined surface 61B of the second cam protrusion 61U2 is located lower than the first inclined surface 61B of the third cam protrusion 61U3 by a height difference L3.

[0063] Here, when the cam protrusion 61 descends by the total height L1 of the first inclined surface 61B shown in Fig. 11 while the first inclined surface 61B of the cam protrusion 61 is in contact with the first inclined surface 51B of the slider 50, the punch 57 advances together with the slider 50 by the stroke S1 shown in Fig. 12. The wall thickness t of the cylindrical workpiece 90 is, for example, about 1 / 6 of the stroke S1, the height difference L2 described above is, for example, about 1 / 3 of the total height L1 of the first inclined surface 61B, and the height difference L3 described above is, for example, about 1 / 2 of the height difference L2.

[0064] With the above-described configuration, when the lifting base 60 is lowered together with the ram 11, as described above, three pairs of six through holes 92A of the second group are drilled in three batches, two at a time, in the second cylindrical portion 92 of the unmachined cylindrical workpiece 90, and at the same time that the last pair of through holes 92A is drilled, the first through hole 91A of the first group is drilled in the first cylindrical portion 91 of the cylindrical workpiece 90, and then the second and third through holes 91A are drilled sequentially at different timings. Then, the lifting base 60 is raised together with the ram 11, and the punch 57 moves away from the cylindrical workpiece 90.

[0065] When all the punches 57 are separated from the cylindrical workpiece 90, the lifting pipe 80 descends. At this time, the knockout pin 58P, which receives the elastic force of the elastic sleeve 59A and the compression coil spring 59B, presses down the cylindrical workpiece 90, and the cylindrical workpiece 90, together with the cylindrical die 70, is released downward from the workpiece receiving section 46.

[0066] Furthermore, as the lifting pipe 80 descends, it temporarily stops or slows down when the upper surface of the guide sleeve 83 retreats below the workpiece conveying surface 19, as shown in FIG. 9 . At this time, the pair of fingers 16 retreat and grip the cylindrical workpiece 90. The lower edges of the opposing surfaces of the pair of fingers 16 are provided with workpiece extraction portions 16T, which have the shape of horizontally extending protrusions, for example. With the lower end of the cylindrical workpiece 90 abutting the workpiece extraction portions 16T of the fingers 16 from above, the lifting pipe 80 descends, and the cylindrical die 70 is extracted from the cylindrical workpiece 90. The pair of fingers 16 then advances, and the cylindrical workpiece 90 is conveyed downstream of the drilling device 40.

[0067] This completes the description of the configuration and operation of the transfer press machine 10 of this embodiment. The transfer press machine 10 provides the following operational effects. That is, in the drilling device 40 of this embodiment, when the cylindrical workpiece 90 is carried into the workpiece standby position coaxially below the workpiece receiving section 46 by the transfer device 14, which is a conveying device as described above, the cylindrical die 70 rises and fits inside the cylindrical workpiece 90, and then the cylindrical workpiece 90 moves upward together with the cylindrical die 70 and is removed from the transfer device 14. Then, as the cylindrical workpiece 90 abuts against the inner surface of the workpiece receiving section 46, the cylindrical die 70 is pressed into the cylindrical workpiece 90, and the cylindrical workpiece 90 is properly set in the cylindrical die 70. That is, in the drilling device 40 of this embodiment, unlike conventional drilling devices in which a cylindrical workpiece is fitted into a cylindrical die below while being removed from a transfer device, the cylindrical workpiece 90 is fitted into the cylindrical die 70 and then removed from the transfer device 14, so that the cylindrical workpiece 90 can be stably and correctly set in the cylindrical die 70. This makes it possible to drill a plurality of through holes 91A, 92A in the cylindrical workpiece 90 with high precision.

[0068] Furthermore, the cylindrical die 70 is supported from below by the compression coil spring 85 and is allowed to move downward relative to the main body of the lift pipe 80 (the portion of the lift pipe 80 other than the cylindrical die 70), so even if the cylindrical workpiece 90 is pushed into the work receiving section 46 while tilted relative to the cylindrical die 70, the posture of the cylindrical workpiece 90 is corrected while suppressing the load that the cylindrical workpiece 90 receives from the inner surface of the work receiving section 46 and the cylindrical die 70. This also allows the cylindrical workpiece 90 to be set stably and correctly relative to the cylindrical die 70.

[0069] Furthermore, in the case of a cylindrical workpiece 90 of this embodiment that has a tapered cylindrical shape toward the top, in a conventional drilling device that pushes the cylindrical workpiece 90 down to set it in a cylindrical die in a workpiece receiving section, the cylindrical workpiece 90 is inserted into the workpiece receiving section from its lower side, which is larger than its upper side. This results in a large space being formed between the cylindrical die and the inner surface of the workpiece receiving section, making support for the punch unstable. In contrast, in the drilling device 40 of this embodiment, the workpiece receiving section 46 receives the cylindrical workpiece 90 from below and narrows toward the top. This allows the cylindrical die 70 and the inner surface of the workpiece receiving section 46 to be closer than in conventional drilling devices, stabilizing support of the punch 57 by the support base 42 and enabling multiple through holes 91A, 92A to be drilled with high precision.

[0070] Furthermore, in order to remove the cylindrical workpiece 90 from the workpiece receiving portion 46, multiple knockout pins 58P press against multiple positions on the step portion 95 provided midway along the axial direction of the cylindrical workpiece 90, so that the cylindrical workpiece 90 can be removed from the workpiece receiving portion 46 in a stable posture.

[0071] In addition, in the punching device 40 of this embodiment, the components that transmit power to the punch 57 (slider 50, cam protrusion 61) are aligned in the vertical direction, so the punching device 40 can be made compact in the direction intersecting the vertical direction. Furthermore, since a plurality of cam protrusions 61 are provided corresponding to a plurality of punches 57, cases in which the positions of the plurality of punches 57 in the vertical direction differ or where it is desired to vary the timing at which the plurality of punches 57 operate can be easily accommodated simply by changing the shape of the cam protrusion 61.

[0072] The punching device 40 of this embodiment has the following feature in the timing of operating the multiple punches 57. That is, in the punching device 40 of this embodiment, the multiple punches 57 surrounding the cylindrical workpiece 90 include multiple pairs of punches 57 arranged on the same line with the cylindrical workpiece 90 in between. The multiple pairs of punches 57 are configured to punch two through holes 92A at a time with staggered timing for a cylindrical workpiece 90 in which multiple through holes 91A, 92A have not yet been drilled. This reduces the impact on the deformation state of the cylindrical workpiece 90 during drilling, which is caused by variations in the length, etc., of the multiple punches 57, between the paired punches 57. Even if the timing of drilling between the paired punches 57 differs, the paired punches 57 are arranged on the same line with the cylindrical workpiece 90 in between, so that the deterioration of the balance of deformation of the cylindrical workpiece 90 during drilling is reduced. That is, according to this embodiment, the plurality of through holes 92A are drilled in the cylindrical workpiece 90 in a more balanced deformed state than in the past, and the plurality of paired through holes 92A can be drilled with higher accuracy than in the past. Also, because the plurality of through holes 92A are drilled two by two, the processing time can be shortened compared to when the drilling timing of the plurality of punches 57 is simply shifted one by one.

[0073] Furthermore, since the plurality of pairs of punches 57 penetrate the cylindrical workpiece 90 and the cylindrical workpiece 90 is stabilized, the plurality of unpaired punches 57 drill the through holes 91A, and therefore the remaining unpaired through holes 91A can be drilled with high processing accuracy. Moreover, the paired punches 57 drill the plurality of through holes 92A in the second cylindrical portion 92, which has a larger diameter than the first cylindrical portion 91 in which the plurality of unpaired punches 57 drill the plurality of through holes 91A, and therefore the support of the cylindrical workpiece 90 when the plurality of unpaired punches 57 drill the through holes 91A becomes even more stable, and the remaining unpaired through holes 91A can be drilled with higher processing accuracy.

[0074] Furthermore, since the transfer press machine 10 of this embodiment is equipped with the above-described drilling device 40, it can drill a plurality of through holes 91A, 92A in the cylindrical workpiece 90 with higher precision than conventional methods. Furthermore, the manufacturing method for the cylindrical workpiece 90 with through holes using the transfer press machine 10 makes it possible to manufacture the cylindrical workpiece 90 with high processing precision.

[0075] [Second embodiment] Although not shown, this embodiment differs from the first embodiment in the structure of the transfer device 14. That is, in the transfer device 14 of this embodiment, a pair of rails 15 is fixed to a slide support base. Meanwhile, a plurality of fingers 16 are supported by the pair of rails 15 so as to be slidable in the front-rear direction H2, and are biased by an elastic member (not shown) in a direction away from the pair of rails 15. In other words, a pair of fingers 16 facing each other in the front-rear direction H2 are biased in a direction toward each other. Then, a workpiece is pushed between the pair of first fingers 16 by the workpiece supply device 13.

[0076] Furthermore, the dummy stage ST2 adjacent to the work supply device 13 is provided with a pair of auxiliary fingers (not shown) facing each other in the horizontal direction H1 in a through hole that passes vertically through the support block 31. Furthermore, the auxiliary fingers receive power from the sub-camshaft 89 and are adapted to appear and disappear above the work transfer surface 19. When a workpiece is carried into the dummy stage ST2 while being clamped between the first fingers 16 in the front-rear direction H2, the auxiliary fingers appear above the work transfer surface 19 and clamp the workpiece from the horizontal direction H1. Thereafter, the second fingers 16 retreat and move to the dummy stage ST2, and when the workpiece that was clamped between the auxiliary fingers in the horizontal direction H1 is clamped from the front-rear direction H2, the auxiliary fingers retreat below the work transfer surface 19. Then, the second fingers 16 advance, and the workpiece is carried into the leading machining stage ST1.

[0077] Similarly to the dummy stage ST2, the first and second reversing dummy stages ST3 are also provided with a pair of auxiliary fingers that appear and disappear above the workpiece transport surface 19. When the cylindrical workpiece 90 is carried into the first reversing dummy stage ST3 by the general fingers 16 upstream of the reversing fingers 16 with the opening 90K facing upward, the auxiliary fingers of the first reversing dummy stage ST3 appear above the workpiece transport surface 19 and clamp and receive the cylindrical workpiece 90 from the lateral direction H1. The reversing fingers 16 then retract and move to the first reversing dummy stage ST3, where they clamp and receive the cylindrical workpiece 90 held by the auxiliary fingers from the front-to-rear direction H2. Thereafter, the auxiliary fingers of the first inversion dummy stage ST3 retreat below the workpiece transfer surface 19, and the inversion fingers 16 move forward while rotating to load the cylindrical workpiece 90 onto the second inversion dummy stage ST3 with the opening 90K facing downward. Then, the auxiliary fingers of the second inversion dummy stage ST3 appear above the workpiece transfer surface 19 and clamp and receive the cylindrical workpiece 90 from the lateral direction H1. Then, the general fingers 16 downstream of the inversion fingers 16 receive the cylindrical workpiece 90 from the auxiliary fingers of the second inversion dummy stage ST3 and load the cylindrical workpiece 90 into the drilling device 40 adjacent to the second inversion dummy stage ST3. In this way, in this embodiment, the inversion device 18 described above is configured by a part of the transfer device 14, the auxiliary fingers, etc.

[0078] [Other embodiments] (1) In the punching device 40 of the above embodiment, the timing at which the unpaired punch 57 first punches the through hole 91A is the same as the timing at which the multiple pairs of punches 57 last punch the through hole 92A, but it may be later or earlier. In other words, as long as at least multiple pairs of punches 57 have punched the through hole 92A, the subsequent punch 57 may punch a through hole in the cylindrical workpiece 90 at any timing. Also, multiple unpaired punches 57 punch the through holes 91A at staggered timings, but they may be configured to punch the through holes 91A at the same timing.

[0079] (2) Furthermore, in the punching device 40 of the above embodiment, the punching timing of each of the multiple pairs of punches 57 is different, while the punching timing is the same between the two punches 57 that make up each pair. However, the punching timing may also be different between the two punches 57 that make up each pair.

[0080] (3) The punches 57 of the punching device 40 in the above embodiment include some that are paired and aligned coaxially across the cylindrical workpiece 90, and some that are not paired, but all of the punches 57 may be paired. Also, when all of the punches 57 are paired, a configuration may be adopted in which all of the pairs of punches 57 punch a plurality of through holes two at a time multiple times, or a configuration may be adopted in which some of the pairs of punches 57 first punch a plurality of through holes two at a time multiple times in the cylindrical workpiece 90, and then the remaining punches 57 punch through holes one by one in sequence regardless of the pairs, or all punch through holes simultaneously.

[0081] (4) In the above embodiment, the cylindrical workpiece 90 has a shape in which the outer diameter changes stepwise halfway along the axial direction, but the entire cylindrical workpiece 90 may be tapered. The entire cylindrical workpiece 90 may also have a uniform diameter. Furthermore, the cross-sectional shape of the cylindrical workpiece 90 is not limited to a circle, and may be, for example, an ellipse or a polygon (rectangle, hexagon).

[0082] (5) The transfer device that transfers the cylindrical workpiece 90 to the drilling device 40 may be, for example, a general-purpose robot having a hand at its tip that grips the cylindrical workpiece 90 .

[0083] (6) In the transfer press 10 of the above embodiment, the ram 11, the transfer device 14, and the punch device 40 are driven by a common drive source, but they may each be driven by a separate drive source.

[0084] (7) In the above embodiment, the drilling device 40 is part of the transfer press 10. However, it may be part of a machine tool separate from the transfer press 10, or may be configured to operate independently.

[0085] (8) Regardless of whether the drilling device 40 is part of the transfer press 10, the power for driving the plurality of punches 57 may be obtained from a path other than the lifting base 60. Specifically, the drilling device 40 may be provided with a plurality of hydraulic cylinders each having a movable rod connected to the plurality of punches 57, and the plurality of hydraulic cylinders may be connected to a hydraulic pump via a plurality of on-off valves, so that the plurality of punches 57 drill the plurality of through holes 91A, 92A at predetermined timing by on-off control of the plurality of on-off valves.

[0086] In addition, instead of the above-mentioned multiple hydraulic cylinders, a configuration may be adopted in which multiple drive source units each having a motor and a ball screw mechanism, rack and pinion mechanism, slider crank mechanism, or the like that converts the rotational output of the motor into a linear movement output are connected to the multiple punches 57.

[0087] Furthermore, a structure may be adopted in which multiple cam grooves are formed on a cam plate that rotates around the central axis of the work receiving portion 46, and cam follower pins protruding from multiple sliders 50 are engaged with these cam grooves, and when the cam plate is rotated by a motor, hydraulic cylinder, etc., multiple punches 57 drill multiple through holes 91A, 92A at predetermined timings in accordance with the differences in the shapes of the cam grooves.

[0088] (9) In the above embodiment, the cylindrical die 70 is movably supported at the upper end of the lift pipe 80, but the main body of the lift pipe 80 and the cylindrical die 70 may be integrated.

[0089] (10) In the above embodiment, the drilling device 40 receives the cylindrical workpiece 90 from below in the workpiece receiving portion 46. However, the cylindrical workpiece 90 may be received from above in the workpiece receiving portion 46, or the axial direction of the workpiece receiving portion 46 may be horizontal or inclined relative to the horizontal direction so that the cylindrical workpiece 90 is received in the workpiece receiving portion 46 from the side or diagonally from the side.

[0090] (11) In the drilling device 40, a plurality of through holes 91A, 92A are drilled by a plurality of punches 57 surrounding the cylindrical workpiece 90. However, for example, a pair of punches 57 may be provided facing each other across the cylindrical workpiece 90, and another punch 57 may be provided at a position rotated a predetermined angle from the punches 57 around the cylindrical workpiece 90, and a rotary drive unit may be provided that rotates the punches 57 around the cylindrical workpiece 90 or rotates the cylindrical workpiece 90, so that the plurality of through holes 91A, 92A are drilled at staggered timings as in the above embodiment.

[0091] (12) In the above embodiment, the first and second inclined surfaces 51B, 51C are provided on the slider 50 that moves together with the punch 57. However, for example, a cylindrical portion having a square cross section may be provided at the end of the punch 57, and a cam hole having the first and second inclined surfaces may be provided in the cylindrical portion.

[0092] <Additional Notes> The following describes the features extracted from the above embodiment, while indicating, as necessary, the effects, etc. Note that, for ease of understanding, the corresponding configurations in the above embodiment are indicated in parentheses as appropriate below, but these features are not limited to the specific configurations indicated in parentheses.

[0093] [Feature 1] A punching device (40) that uses a plurality of punches (57) surrounding a cylindrical workpiece (90) to punch a plurality of through holes (91A, 92A) from the side of the cylindrical workpiece (90), wherein the plurality of punches (57) include a plurality of pairs of punches (57) that are arranged in the same straight line with the cylindrical workpiece (90) in between, and the plurality of pairs of punches (57) are configured to punch the through holes (92A) two at a time with staggered timing for a cylindrical workpiece (90) that has not yet been punched with the plurality of through holes (91A, 92A).

[0094] In the punching device of Feature 1, the multiple punches surrounding the cylindrical workpiece include multiple pairs of punches arranged on the same line with the cylindrical workpiece sandwiched between them. The multiple pairs of punches are configured to punch through holes two at a time, with timing staggered, into a cylindrical workpiece that does not already have multiple through holes drilled. This minimizes the impact on the deformation state of the cylindrical workpiece during punching due to variations in the length of the multiple punches between the paired punches. Even if the timing of punching between the paired punches is shifted, the paired punches are arranged on the same line with the cylindrical workpiece sandwiched between them, thereby minimizing the deterioration of the balance of deformation of the cylindrical workpiece during punching. In other words, according to Feature 1, multiple through holes are drilled in the cylindrical workpiece in a more balanced deformation state than in the past, enabling multiple through holes to be drilled with higher accuracy than in the past.

[0095] [Feature 2] The punching device (40) according to Feature 1, wherein each pair of the punches (57) is configured to punch the through holes (92A) at the same timing.

[0096] According to the configuration of feature 2, multiple through holes are punched two at a time, which shortens the processing time compared to when multiple punches are simply punched one at a time.

[0097] [Feature 3] The punching device (40) according to feature 1 or 2 is configured such that the punch (57) of the pair that first punched the through hole (92A) penetrates the cylindrical workpiece (90), and the subsequent punch (57) of the pair then punches the through hole (92A).

[0098] According to Feature 3, as the number of drilled through holes increases, the cylindrical workpiece becomes more stable and the machining accuracy improves.

[0099] [Feature 4] The punching device (40) according to any one of features 1 to 3, wherein the plurality of punches (57) includes the plurality of unpaired punches (57), and the plurality of unpaired punches (57) are configured to punch the through holes (91A) when the plurality of paired punches (57) penetrate the cylindrical workpiece (90).

[0100] According to Feature 4, since a plurality of pairs of punches penetrate the cylindrical workpiece and the cylindrical workpiece is stabilized, a plurality of unpaired punches drill through holes, and therefore the remaining unpaired through holes can also be drilled with high processing accuracy.

[0101] [Feature 5] The punching device (40) according to Feature 4, wherein the plurality of unpaired punches (57) are configured to punch the through holes (91A) one by one with a staggered timing.

[0102] As in Feature 5, the punches that are not paired may punch the through holes one by one with staggered timing, or may punch the through holes simultaneously.

[0103] [Feature 6] The punching device (40) according to Feature 5 is configured so that the timing at which the plurality of pairs of punches (57) finally punch the through hole (92A) is the same as the timing at which the plurality of unpaired punches (57) first punch the through hole (91A).

[0104] According to Feature 6, the machining time for cylindrical workpieces can be reduced.

[0105] [Feature 7] The cylindrical workpiece (90) has a first cylindrical portion (91) in the axial direction and a second cylindrical portion (92) having a diameter larger than that of the first cylindrical portion (91), and a plurality of through holes (92A) are drilled in the second cylindrical portion (92) by the plurality of pairs of punches (57), and a plurality of through holes (91A) are drilled in the first cylindrical portion (91) by the plurality of punches (57) that are not paired, in the drilling device (40) described in feature 4.

[0106] According to Feature 7, the support of the cylindrical workpiece by the paired punches becomes more stable, and the machining accuracy of through holes by a plurality of punches that are not paired increases.

[0107] [Feature 8] A drilling device (40) according to any one of features 1 to 7, comprising: a support base (42) having a work receiving portion (46) that receives the cylindrical work (90) and that slidably supports the plurality of punches (57) so that they can move forward and backward relative to the work receiving portion (46); an elevating base (60) that moves linearly up and down and has a plurality of cam protrusions (61) corresponding to the plurality of punches (57) that protrude toward the support base (42); and sliding contact portions (51B, 61B) that are provided on each of the corresponding cam protrusions (61) and each of the punches (57) or on a member (50) that moves together with each of the punches (57), that slide against each other, and that convert the linear movement of the cam protrusions (61) into forward movement of the punch (57) relative to the cylindrical work (90).

[0108] According to the configuration of Feature 8, the components of the punching device that transmit power to the punches are arranged in the vertical direction, so the punching device can be made compact in the direction intersecting the vertical direction. Also, since multiple cam protrusions are provided corresponding to multiple punches, cases where the positions of multiple timings in the vertical direction differ or where it is desired to differ the timings at which multiple punches are operated can be easily accommodated simply by changing the shape of the cam protrusions.

[0109] [Feature 9] The work receiving portion (46) has an opening at its lower end, and a work transport space (40V) is provided below the support base (42), and the punching device according to feature 8 is provided with: a transport device (14) that transports the cylindrical work (90) from a horizontal direction to a work standby position coaxially below the work receiving portion (46) in the work transport space (40V); an elevating pipe (80) that moves linearly up and down below the work receiving portion (46) and pushes the cylindrical work (90) at the work standby position into the work receiving portion (46) from below; and a cylindrical die (70) that is provided at the upper end of the elevating pipe (80), is fitted into the cylindrical work (90), and has a punching hole through which the punch (57) advances and retreats.

[0110] In the drilling device of Feature 9, when a cylindrical workpiece is carried into a workpiece standby position coaxially below the workpiece receiving section by the conveying device, the cylindrical die rises and fits inside the cylindrical workpiece, and then the cylindrical workpiece moves upward together with the cylindrical die and is released from the conveying device. Then, as the cylindrical workpiece abuts against the inner surface of the workpiece receiving section, the cylindrical die is pushed into the cylindrical workpiece, and the cylindrical workpiece is properly set in the cylindrical die. That is, unlike conventional drilling devices in which the cylindrical workpiece is fitted into the lower cylindrical die while being released from the conveying device, the drilling device of Feature 9 allows the cylindrical workpiece to be stably and properly set in the cylindrical die after being fitted into the cylindrical die. This allows for the drilling of multiple through holes with high precision.

[0111] [Feature 10] A drilling device (40) according to Feature 9, wherein the cylindrical work (90) has a cylindrical shape tapering toward the upper side, and the work receiving portion (46) narrows toward the upper side.

[0112] In the case of a cylindrical workpiece that tapers toward the top, like the cylindrical workpiece of feature 10, in a conventional drilling device that pushes the cylindrical workpiece down to set it in a cylindrical die in a workpiece receiving section, the cylindrical workpiece is inserted into the workpiece receiving section from its bottom, which is larger than its top. This creates a wide space between the cylindrical die and the inner surface of the workpiece receiving section, making support for the punch unstable. In contrast, in the drilling device of feature 10, the workpiece receiving section receives the cylindrical workpiece from below and narrows toward the top, so the cylindrical die and the inner surface of the workpiece receiving section can be closer than in conventional drilling devices, stabilizing support for the punch by the support base and enabling multiple through holes to be drilled with high precision.

[0113] [Feature 11] A transfer press (10) intermittently transports a workpiece to each of a plurality of processing stages (ST1) arranged in a row in the horizontal direction between a lower table (12) and a ram (11) above it by a transfer device (14), and forms the workpiece into a cylindrical workpiece (90) with a closed bottom end and an open top end by a plurality of punches (20) provided on the underside of the ram (11) and a plurality of dies (30) provided on the lower table (12). A transfer press machine (10) comprising an inversion device (18) that inverts the bottom, and a drilling device (40) according to feature 9 or 10 that is provided on the processing stage (ST1) downstream of the inversion device (18), wherein the support base (42) is supported by a support member (41) that stands up from the lower table (12), the transfer device (14) also serves as the conveying device (14) for the drilling device (40), and the lifting pipe (80) is passed through a through hole (31H) that passes vertically through the lower table (12).

[0114] The transfer press of Feature 11 has the drilling device described in Feature 9 and has the configuration of Feature 1, so similar to Feature 1 described above, it can drill multiple through holes with higher accuracy than conventional methods.

[0115] [Feature 12] A method for manufacturing a cylindrical workpiece (90) with through holes by drilling a plurality of through holes (91A, 92A) at a plurality of positions in the circumferential direction of the cylindrical workpiece (90), wherein the plurality of through holes (91A, 92A) includes a plurality of pairs of through holes (92A) arranged on the same straight line across the central axis of the cylindrical workpiece (90), and the plurality of pairs of through holes (92A) are drilled at staggered timing for a cylindrical workpiece (90) that has not been drilled with the plurality of through holes (91A, 92A).

[0116] According to the method for manufacturing a cylindrical workpiece with a through hole of feature 12, the same effects as those of the drilling device of feature 1 are achieved.

[0117] Although the present specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and variations of the specific examples, and also includes parts of the specific examples taken out alone. [Explanation of symbols]

[0118] 10 Transfer press machine 11. Rum 12 Lower platform 14 Transfer device (transport device) 18 Inverter 20 punches 30 Die 40 Drilling device 40V Work transport space 41 Support member 42 Support Base 46 Work receiving section 50 sliders 51B, 51C, 61B, 61C Inclined surface (sliding contact part) 57 Punch 60 Lifting base 61 Cam protrusion 70 Cylindrical die 80 Lifting pipe 90 Cylindrical workpiece 91A,92A through hole

Claims

1. A punching device that punches a plurality of through holes in a cylindrical workpiece from the side using a plurality of punches that surround the cylindrical workpiece, The plurality of punches include a plurality of pairs of punches arranged in the same straight line sandwiching the cylindrical workpiece, and a plurality of punches that are not paired, and the plurality of pairs of punches punch the through holes two at a time at staggered timing for a cylindrical workpiece in which the plurality of through holes have not been drilled, and when the plurality of pairs of punches have penetrated the cylindrical workpiece, the plurality of unpaired punches drill the through holes.

2. The punching device according to claim 1 , wherein each pair of punches is configured to punch the through holes at the same timing.

3. 2. The punching device according to claim 1, wherein the punch of the pair that first punched the through hole has penetrated the cylindrical workpiece, and the punch of the subsequent pair punches the through hole.

4. A perforation device as described in Claim 1, wherein the plurality of unpaired punches are configured to perforate the through holes one by one at staggered timing.

5. A perforation device as described in Claim 4, which is configured so that the timing at which the plurality of pairs of punches last perforate the through holes is the same as the timing at which the plurality of unpaired punches first perforate the through holes.

6. The cylindrical workpiece has a first cylindrical portion in the axial direction and a second cylindrical portion having a larger diameter than the first cylindrical portion, and the drilling device described in claim 1 is configured so that a plurality of through holes are drilled in the second cylindrical portion by the plurality of pairs of punches, and a plurality of through holes are drilled in the first cylindrical portion by the plurality of punches that are not paired.

7. A support base having a work receiving portion that receives the cylindrical workpiece and that slidably supports the plurality of punches so that they can advance and retreat relative to the work receiving portion; a lifting base that moves linearly up and down and has a plurality of cam protrusions that correspond to the plurality of punches and that protrude toward the support base; 7. The drilling device according to claim 1, further comprising: sliding contact portions provided on the corresponding cam protrusions and on the punches or on members that move together with the punches, which are in sliding contact with each other and convert the vertical linear movement of the cam protrusions into forward movement of the punch relative to the cylindrical workpiece.

8. The workpiece receiving portion has an opening at a lower end, A workpiece transport space is provided below the support base, a conveying device that horizontally conveys the cylindrical workpiece into a workpiece standby position coaxially below the workpiece receiving portion within the workpiece conveying space; an elevating pipe that moves linearly up and down below the work receiving portion and pushes the cylindrical workpiece at the work waiting position into the work receiving portion from below; a cylindrical die provided at an upper end of the lifting pipe, fitted into the cylindrical workpiece, and having a punching hole through which the punch advances and retreats; The drilling device according to claim 7, comprising:

9. The cylindrical workpiece has a cylindrical shape tapered toward the upper side, The drilling device according to claim 8, wherein the workpiece receiving portion narrows upward.

10. A transfer press machine in which a workpiece is intermittently conveyed by a transfer device to each of a plurality of processing stages arranged in a row horizontally between a lower table and a ram above it, and the workpiece is formed into a cylindrical workpiece with a closed bottom end and an open top end by a plurality of punches provided on the underside of the ram and a plurality of dies provided on the lower table, An inversion device provided on the processing stage at a position near the downstream end and inverting the cylindrical workpiece upside down; and the drilling device according to claim 8, which is provided on the processing stage downstream of the reversing device, The support base is supported by a support member that stands up from the lower platform, the transfer device also serves as the transport device of the punching device, The lifting pipe is passed through a through hole that passes vertically through the lower table.

11. A method for manufacturing a cylindrical workpiece with through holes by drilling a plurality of through holes at a plurality of positions in the circumferential direction of the cylindrical workpiece, comprising: The plurality of through holes include a plurality of pairs of through holes arranged on the same straight line across the central axis of the cylindrical workpiece, and a plurality of unpaired through holes, and the plurality of pairs of through holes are drilled at staggered times in a cylindrical workpiece that has not been drilled with the plurality of through holes, and the plurality of unpaired through holes are drilled when the plurality of pairs of punches that drilled the plurality of pairs of through holes have penetrated the cylindrical workpiece.

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