Punch for press-working and press-working apparatus provided with the same

Abstract

To provide a punch for press working which can manufacture a cutting blade with an ultrahard material without weakening punch strength and firmly fix the cutting blade so that it does not fall off and whose resonance frequency can be easily adjusted, and a press working apparatus provided with the punch.SOLUTION: A flange-like holding part is provided on an outer peripheral edge of the middle part of a steel punch to be attached to a top die of a press working apparatus, and a cutting blade formed of an ultrahard material is attached at the tip of the punch.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to a punch for press working and a press working apparatus equipped with the same, and more particularly to a punch for press working having a structure in which a cutting blade made of super steel is firmly attached to the tip of a punch made of steel material mounted on the upper die of the press working apparatus and a press working apparatus equipped with the same.

Background Art

[0002] Generally, press working includes separation working, forming working, etc., and the apparatuses used for these workings are generally called press working apparatuses. A press working apparatus places a workpiece between a die composed of an upper die and a lower die (die), sandwiches and presses the workpiece with the upper and lower dies, and processes the workpiece into a desired shape.

[0003] Separation working forms a shape by cutting a workpiece. For example, there is known a blanking process in which a workpiece is placed on a lower die and the shape is punched with an upper die. Further, forming working includes, for example, bending working for bending a workpiece and drawing working for stretching and forming a workpiece. However, in separation working, "burrs" and "flashes" occur at the starting and ending portions of the shear surface, and the states of these "burrs" and "flashes" vary depending on the thickness and type of the workpiece plate, the processing speed, the clearance, etc. When a large amount of "flashes" occurs, the flatness of the shear surface is impaired, which becomes a problem when the flatness of the shear surface is required. Also, since "burrs" have sharp tips, they can cause injuries and product failures.

[0004] In forming working, there is a risk of quality degradation due to the occurrence of "scratches" and "cracks" during bending working depending on the thickness and type of the workpiece plate, the processing speed, the clearance, etc. Also, in drawing working, there is a risk of "wrinkles" and "cracks" occurring depending on the thickness and type of the workpiece plate, the processing speed, the clearance, etc.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent No. 6427438 Summary of the Invention Problems to be Solved by the Invention

[0006] As a solution to the above problems, for example, a press working apparatus and a punch disclosed in Japanese Patent No. 6427438 (Patent Document 1) are known. That is, as shown in FIG. 1, the press working apparatus 1 includes a movable side portion (upper die) 2 having a punch 10 and a fixed side portion 3 having a lower die 30. The movable side portion 2 includes the punch 10, a hold plate 21A for fixing the punch 10, a back plate 21B, and a support 23 for fixing the hold plate 21A and the back plate 21B to an upper die holder 22. The upper die holder 22 and the support 23 are fixed by bolts 24A, and similarly, the support 23, the hold plate 21A, and the back plate 21B are fixed by bolts 24B. The punch 10 is held and fixed by the hold plate 21A and the back plate 21B by a flange-shaped holding portion 11 provided around the middle portion, and the other portions are not fixed. That is, when the punch 10 is vertically vibrated by the vibrator 20, the vibration is not transmitted to the stripper 25 or the support 23.

[0007] Further, the movable side portion 2 includes a stripper 25 for peeling when a workpiece W adheres to the punch 10, a spring 26 for urging the stripper 25 toward the lower die 30, and a guide pin 27 for stabilizing the posture of the stripper 25. Further, a vibrator 20 driven by a driving portion is fixedly disposed on the vibrating end (upper surface) of the punch 10.

[0008] On one side, the fixed-side part 3 includes a lower die 30 and a lower die holder 32 that fixes the lower die 30. The lower die 30 is a metal member having a predetermined thickness, and is laminated on the lower die holder 32 and fixed by bolts 34. Further, the lower die 30 has a hole 31 having a shape corresponding to the shape of the punch 10 and a hole 33 for receiving the guide pin 27. Note that the press working apparatus 1 is provided with a drive mechanism (not shown) for applying a force necessary for processing to the mold, a control mechanism (not shown) for controlling the drive mechanism, a safety device (not shown), and the like.

[0009] FIGS. 2(A) and (B) show an example of a punch. The punch 10 shown in FIG. 2(A) has a rectangular cross section in the horizontal direction, and flange-shaped holding portions 11 are provided at intermediate portions of both side surfaces. A through hole 12 is formed horizontally by notching the central portion of the holding portion 11, and the through hole 12 is one hole distributed in the vertical direction with respect to the surface of the holding portion 11. Further, the punch 10A shown in FIG. 2(B) has a circular cross section in the horizontal direction, and a flange-shaped holding portion 11A is provided around the intermediate portion of the side surface. A through hole 13 is formed horizontally by notching a part (two opposed portions) of the holding portion 11A, and the through hole 13 is one hole distributed in the vertical direction with respect to the surface of the holding portion 11A.

[0010] In such a configuration, the punches in press working are used separately according to the processing type and the workpiece W. The workpiece W placed on the upper surface of the lower die 30 is subjected to press working such as separation processing by the reciprocating motion of the punch 10 (10A) by the drive mechanism and the vibration of the vibrator 20. At this time, the processing quality is improved by the resonance action of the through holes 12 (13) formed in the punch 10 (10A).

[0011] However, in the conventional punch, since a part of the holding portion is notched due to the through hole, there is a problem that the strength of the punch is reduced. Further, when there is a notch in the holding portion, it becomes difficult to provide a D-cut for circumferential restraint and positioning, especially in the case of a cylindrical punch. Furthermore, since the through hole drilled so as to penetrate the holding portion expands and contracts vertically and horizontally due to the vibration of the vibrator, frictional loss occurs when the holding portion expands and contracts in the lateral direction (perpendicular to the axis), and there is a problem that the vibration transmission effect deteriorates. In order to improve the vibration transmission effect, it is necessary to reduce the lateral expansion and contraction. Therefore, it is necessary to adjust the resonance frequency of the punch body with respect to the vibrator 20, and conventionally, it has been adjusted by the size of one through hole.

[0012] Also, although the punch body is generally made of steel (tool steel, alloy steel, etc.), the cutting edge to be processed is severely worn, and countermeasures are required in terms of maintenance and inspection. Therefore, there has also appeared a punch body made entirely of super steel including the cutting edge. In this case, the performance of the cutting edge is improved, but it is difficult to adjust and drill the through hole as described above, and there is a problem that it becomes very difficult to adjust the resonance frequency by its size.

[0013] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a press working punch that can be made of super steel only for the cutting edge without weakening the punch strength, firmly fix the cutting edge so that it does not fall off, and is easy to adjust the resonance frequency, and a press working apparatus equipped with the same.

Means for Solving the Problems

[0014] The present invention relates to a press working punch, and the above object of the present invention is achieved by providing a flange-shaped holding portion on the outer surface of the middle part of a steel punch mounted on the upper die of a press working apparatus, and mounting a cutting edge made of super steel on the tip of the punch.

Effects of the Invention

[0015] Since the holding part provided on the outer surface of the punch of the present invention is not notched, it can be held and fixed to a press working apparatus without reducing rigidity and strength. Further, in the present invention, only the cutting blade is made of super steel material and the cutting blade is firmly fixed, so that damage to the cutting blade can be reduced, the service life of the cutting blade can be extended, and maintenance and inspection work can also be reduced. Moreover, since the punch body is made of steel material, adjustment of the resonance frequency can be easily performed.

Brief Description of the Drawings

[0016]

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Embodiments for Carrying Out the Invention

[0017] In a conventional punch for press working, as shown in FIGS. 2(A) and (B), a notch is provided in a holding portion provided around the outside of the punch body, which reduces the rigidity and strength. In contrast, in the present invention, the necessary rigidity and strength are maintained without providing a notch in the holding portion.

[0018] First, an example of a punch to which the present invention can be applied will be described with reference to FIGS. 3 to 5.

[0019] The punch 10 in FIG. 3(A) is obtained by eliminating the notch in the holding portion 11 in the conventional FIG. 2(A), and the punch 10A in FIG. 3(B) is obtained by eliminating the notch in the holding portion 11A in the conventional FIG. 2(B). Each punch has one through hole and no notch is provided in the holding portion. The punch 100 in FIG. 4 shows an example in which a holding portion 100-1 without a notch is provided in the middle portion, a through hole 100-2 is provided in the upper punch body of the holding portion 100-1, and a through hole 100-3 is provided in the lower punch body. Also, the punch 100 shown in FIG. 5 is the same as the punch in FIG. 4, but the surfaces of the holding portion 100-1 respectively constitute a part of the through holes 100-2 and 100-3. Since the punches in FIGS. 4 and 5 are provided with two through holes 100-2 and 100-3 above and below the holding portion 100-1, it is easy to adjust the resonance frequency. The present invention can be applied to any of the above punches, but in the following description, for convenience, the through holes will be omitted from the description.

[0020] In addition, a conventional general punch is entirely made of steel, and damage and wear of the cutting edge have been major problems. There are also punches whose entire body is made of super steel, but as described above, the resonance frequency cannot be adjusted. Therefore, in the present invention, only the cutting edge is made of super steel, and the other parts are made of steel. At the same time, the cutting edge made of super steel is firmly fixed to the punch bottom made of steel so as not to fall off, aiming to extend the service life of the cutting edge. In the steel part, the resonance frequency can be easily adjusted by means of a through hole. There are differences in characteristics between steel and super steel as shown in Table 1 below. If the attachment of the cutting edge is not made firm, there will be a problem of falling off. Therefore, in the present invention, the attachment and fixing method is devised.

[0021]

Table 1

[0022] In the present invention, while ensuring the function of the conventional holding part, the effect of not providing a notch, the ease of adjusting the resonance frequency, and the features of the cutting edge made of super steel that does not fall off are utilized.

[0023] Hereinafter, embodiments of the present invention will be sequentially described with reference to the drawings.

[0024] In the first embodiment of the present invention shown in FIG. 6, a flange-shaped holding portion 103 is provided around the outer peripheral edge of the middle portion of the punch 100, and no notch is provided in the holding portion 103. The upper side of the holding portion 103 is the vibrator-side punch body 101, and the lower side is the tip-side punch body 102. The vibrator-side punch body 101, the tip-side punch body 102, and the holding portion 103 are made of a steel material such as tool steel. At the bottom of the tip-side punch body 102, a long and concave coupling groove 102-1 is provided. The cutting blade member 110 that engages and is mounted in this engagement groove 102-1 has a cutting blade surface 110A and has a shape as shown in FIGS. 7(A) and 7(B). FIG. 7(A) is a plan view, and FIG. 7(B) is a side view. That is, a long and convex engagement protrusion 111 is provided at the center of the disk-shaped main body upper surface 112, and through screw holes 113 are provided on both sides of the engagement protrusion 111.

[0025] In this example, two screw holes 113 are provided, but an appropriate number can be set. Also, the screw holes 113 may be round holes.

[0026] In such a configuration, the engagement protrusion 111 of the cutting blade member 110 is engaged with the coupling groove 102-1 at the bottom of the tip-side punch body 102, and a screw 150 is passed through the screw hole 113 and screwed and fastened to the screw hole at the bottom of the tip-side punch body 102. A part of the fastened state is shown in FIG. 8. In addition to such screwing, the joint surface may be brazed or adhered with an anaerobic adhesive. That is, the bottom of the tip-side punch body 102 and the main body upper surface 112 of the cutting blade member 110 are brazed or adhered with an anaerobic adhesive.

[0027] Note that brazing or adhesion with an anaerobic adhesive can be applied in any of the embodiments described below.

[0028] Figure 9 shows the second embodiment of the present invention, where the concavo-convex relationship of the first embodiment is reversed. That is, a long convex coupling protrusion groove 102-2 is provided at the bottom of the tip-side punch body 102. The cutting blade member 110 that is engaged and attached to the engaging protrusion 102-2 has a cutting blade surface 110A and has the shape as shown in FIGS. 10(A) and 10(B). FIG. 7(A) is a plan view, and FIG. 10(B) is a side view. An engaging groove 112, which is a long concave portion, is provided at the center of the upper surface 112 of the disc-shaped body, and through screw holes 113 are provided on both sides of the engaging groove 112.

[0029] In such a configuration, the engaging groove 112 of the cutting blade member 110 is engaged with the coupling protrusion 102-2 at the bottom of the tip-side punch body 102, and at the same time, a screw 150 is passed through the screw hole 113 and screwed and fastened in the same manner as in the first embodiment.

[0030] Figure 11 shows the third embodiment of the present invention, where the cutting blade member 110 in the first embodiment is miniaturized (thinned). As shown in FIG. 11, a long concave coupling groove 102A-1 is provided at the bottom of the tip-side punch body 102. The cutting blade member 120 that is engaged and attached to the engaging groove 102A-1 has a small (thickness D2 (<D1)) shape as shown in FIGS. 12(A) and 12(B). A long convex engaging protrusion 121 is provided at the center of the upper surface 122 of the disc-shaped body, and screw holes 123 are provided on both sides of the engaging protrusion 121.

[0031] In such a configuration, the engaging protrusion 121 of the cutting blade member 120 is engaged with the coupling groove 102A-1 at the bottom of the tip-side punch body 102, and at the same time, a screw 151 is passed through the screw hole 123 and screwed and fastened. When the volume of the super steel material becomes large, there are the above-mentioned inconveniences. Therefore, it is desirable that the volume of the cutting blade member 120 as shown in FIGS. 11 and 12 is small.

[0032] FIG. 13 shows the fourth embodiment of the present invention, which is the reverse of the concavo-convex relationship in the third embodiment. That is, as shown in FIG. 13, a long and concave coupling projection 102A-2 is provided at the bottom of the tip-side punch body 102. The cutting blade member 120 that is engaged and attached to the engaging projection 102A-2 has a small (thickness D4 (<D1)) shape as shown in FIGS. 14(A) and (B). A long and concave engaging groove 124 is provided at the center of the upper surface 122 of the disk-shaped main body, and screw holes 123 are provided on both sides of the engaging groove 124.

[0033] In such a configuration, the engaging groove 124 of the cutting blade member 120 is engaged with the coupling projection 102A-2 at the bottom of the tip-side punch body 102, and a screw 151 is passed through the screw hole 123 and screwed and fastened.

[0034] Next, the fifth embodiment of the present invention will be described with reference to FIG. 15. In the fifth embodiment, a concave screw hole 102B-1 whose periphery is threaded with a female screw 102B-2 is provided at the center of the bottom surface of the tip-side punch body 102B, and the cutting blade member 130 is provided with a disk-shaped engaging portion 131 having a convex male screw 132 at the center.

[0035] Then, while the engaging portion 131 is fitted into the screw hole 102B-1, the cutting blade member 130 is rotated so that the male screw 132 and the female screw 102B-2 are screwed and inserted. In a state where the bottom surface of the tip-side punch body 102B and the upper surface of the cutting blade member 130 are in contact with each other, it is firmly fixed as shown in FIG. 15(B).

[0036] Further, FIG. 16 shows the sixth embodiment of the present invention, which has a structure in which the concavo-convex relationship in the fifth embodiment is reversed. That is, in the sixth embodiment, a convex protrusion 102B-4 with a peripheral edge threaded with a male screw 102B-3 is provided at the center of the bottom surface of the tip-side punch body 102B. A recess is formed in the center of the cutting blade member 130, and an engaging screw hole 131-1 having a female screw 133 on the peripheral side surface is provided. Then, while fitting the protrusion 102B-4 into the engaging screw hole 131-1, by relatively rotating the cutting blade member 130, the male screw 102B3 and the female screw 133 are screwed and inserted, and the bottom surface of the tip-side punch body 102B and the upper surface of the cutting blade member 130 are in contact with each other. In this state, it is firmly fixed as shown in FIG. 16(B).

[0037] Next, the seventh embodiment of the present invention will be described with reference to FIG. 17. In the seventh embodiment, a female screw hole 102B-2 drilled in the center of the bottom surface of the tip-side punch 102B and a female screw hole 133 drilled in the center of the upper surface of the cutting blade portion 130 are provided. Then, the cutting blade portion 130 is fastened to the bottom surface of the tip-side punch by a male screw rod 200 that is screwed into the screw holes 102B-2 and 133. For example, after screwing the male screw rod 200 into the screw hole 102B-2 and inserting it, the male screw at the other end of the male screw rod 200 is screwed into the screw hole 133 of the cutting blade portion 130 and inserted. The reverse is also possible.

[0038] Further, FIG. 18 shows the eighth embodiment of the present invention. The point of drilling a female screw hole 102B-2 in the center of the tip-side punch 102B is the same as that in the seventh embodiment. However, in the eighth embodiment, a recess 130-3 is provided in the center of the upper surface of the cutting blade portion 130, and a penetrated female screw hole 130-2 is provided. Then, a male screw rod 201 is screwed into the screw hole 130-2, and the tip of the male screw rod 201 is screwed into the screw hole 102B-2, thereby fastening the cutting blade portion 130 to the bottom surface of the tip-side punch 102B.

[0039] Next, the ninth embodiment shown in FIGS. 19 to 22 will be described.

[0040] In this ninth embodiment, a so-called dovetail joint and a wedge mounting method are used to attach the cutting blade member 140 to the tip-side punch body 102C. As shown in FIG. 19, at the central portion on the connection side of the cutting blade member 140, an engaging convex portion 141 having an inverted "H" cross-section is provided in a wedge shape, and at the bottom of the tip-side punch body 102C, an engaging concave portion 102C-1 in the shape of an "H" is provided in a wedge shape. The engaging convex portion 141 and the engaging concave portion 102C-1 are in a shape relationship that fits with each other. The cross-sectional view of the tip-side punch body 102C along the line X1-X2 in FIG. 19 is FIG. 20, FIG. 21 is a plan view of the cutting blade member 140, the cross-sectional view along the line Y1-Y2 in FIG. 21 is FIG. 22(A), and the cross-sectional view along the line Z1-X2 is FIG. 22(B).

[0041] In the ninth embodiment, the engaging convex portion 141 provided on the upper surface of the cutting blade member 140 fits into the engaging concave portion 102C-1 provided at the bottom of the tip-side punch body 102C in a wedge shape and engages therewith, and is firmly fixed. Since the engaging convex portion 141 and the engaging concave portion 102C-1 form a dovetail joint, dropping in the vertical direction can be completely prevented. At that time, as shown in FIG. 23, by providing an anti-backward movement protrusion 102C-2 on the surface of the engaging concave portion 102C-1 and an anti-backward movement protrusion 141-1 on the surface of the engaging convex portion 141, dropping in the horizontal direction can also be completely prevented, and a stronger fixation can be realized.

[0042] In the ninth embodiment, the engaging concave portion 102C-1 and the engaging convex portion 141 are formed in a wedge shape, but in order to simplify and facilitate manufacturing, a parallel line shape as shown in FIGS. 24 and 25 may be used (tenth embodiment). That is, in the tenth embodiment, the engaging concave portions 102C-1 are provided in parallel as shown in FIG. 24, and the engaging convex portions 141 are also provided in parallel as shown in FIG. 22. Therefore, the cutting blade member 140 can be attached to the tip-side punch body 102C from any direction.

[0043] Next, the 11th embodiment of the present invention will be described with reference to FIG. 26. The 11th embodiment has an engagement relationship opposite to that of the 9th embodiment shown in FIG. 19. That is, as shown in FIG. 26, an engagement recess 162 having a “C” - shaped cross - section is provided in parallel at the central portion on the connection side of the cutting blade member 160. As shown in FIG. 28, an inverted “C” - shaped engagement protrusion 102D - 1 is provided in parallel at the bottom of the tip - side punch body 102D. Then, the engagement recess 162 provided on the upper surface of the cutting blade member 160 fits and engages with the engagement protrusion 102D - 1 provided at the bottom of the tip - side punch body 102D, and is firmly fixed.

[0044] Although the engagement protrusion 102D - 1 in FIG. 27 and the engagement recess 162 in FIG. 28 are parallel, they may have corresponding wedge - like shapes as shown in FIGS. 20 to 22 (12th embodiment).

[0045] In each of the above examples, a punch with a circular cross - section has been described. However, as shown in FIG. 29, a punch with a rectangular cross - section may also be used. That is, in the example of FIG. 29(A), holding portions 101A and 101B without notches are provided opposite each other on the outer surface of the punch 100 so as to be orthogonal to the through - holes 100 - 2 and 100 - 3. In the example of FIG. 29(B), holding portions 101C and 101D without notches are provided opposite each other on the outer surface of the punch 100 in parallel with the through - holes 100 - 2 and 100 - 3. In the example of FIG. 29(C), holding portions 101A and 101B without notches are provided opposite each other on the outer surface of the punch 100 so as to be orthogonal to the through - holes 100 - 2 and 100 - 3, and holding portions 101C and 101D without notches are provided opposite each other on the outer surface of the punch 100 in parallel with the through - holes 100 - 2 and 100 - 3. Even with such a configuration, a cutting blade made of super steel can be mounted in the same manner as described above.

[0046] Note that in FIG. 29, an example in which the through - holes 100 - 2 and 100 - 3 are provided is shown, but a punch without the through - holes 100 - 2 and 100 - 3 may also be used.

Explanation of Reference Numerals

[0047] 1 Press Working Device 2 Movable Side Part (Upper Die) 3 Fixed Side Part 10, 10A Punches 11, 11A Holding Parts 12, 13 Through-Holes 20 Vibrator 20A Connection Part The 21A Hold Plate 21B Back Plate 22 Upper Die Holder 23 Support 24A, 24B, 34 Bolts 25 Stripper 26 Spring 27 Guide Pin 30 Lower Die 31, 33 Holes 32 Lower Die Holder 100, 100A, 100B, 100C Punches 101 Vibrator Side Punch Body 102 Tip Side Punch Body 103 Holding Part 110, 120, 130, 140 Cutting Blade Members 111 Engagement Protrusion 113 Screw Hole 150, 151 Screws 160 Cutting Blade Member 200, 201 Male Screw Rods

Claims

1. A punch for press working, characterized in that a flange-shaped holding portion is provided on an outer surface of a middle portion of a punch made of steel material mounted on an upper die of a press working apparatus, and a cutting blade made of super steel material is mounted on a tip portion of the punch.

2. The punch for press working according to claim 1, wherein the holding portion is not provided with a notch.

3. The punch for press working according to claim 1 or 2, wherein the cutting blade is mounted on the tip portion of the punch by engagement of uneven portions provided on the tip portion and uneven portions provided on an upper surface of the cutting blade, and screwing through the cutting blade.

4. The punch for press working according to claim 3, wherein a contact surface between the tip portion of the punch and the cutting blade is adhered by roll bonding or an anaerobic adhesive.

5. The punch for press working according to claim 1 or 2, wherein the cutting blade is mounted on the tip portion of the punch by screwing of a first screw hole of a female screw bored in a central portion of the tip portion of the punch or a first screw projection of a convex male screw, and a second screw projection of a convex male screw provided in a central portion of an upper surface of the cutting blade or a second screw hole of a bored female screw.

6. The punch for press working according to claim 1 or 2, wherein the cutting blade is mounted on the tip portion of the punch by a first male screw rod screwed into a third screw hole of a female screw bored in a central portion of the tip portion of the punch and a fourth screw hole of a female screw bored in a central portion of an upper surface of the cutting blade.

7. The punch for press working according to claim 1 or 2, wherein the cutting blade is mounted on the tip portion of the punch by a second male screw rod screwed into a fifth screw hole of a female screw bored in a central portion of the tip portion of the punch and a sixth screw hole of a female screw penetrated in a central portion of an upper surface of the cutting blade.

8. The punch for press working according to claim 1 or 2, wherein the cutting blade is mounted on the tip portion of the punch by fitting of a first elongated groove or a first elongated projection provided on the tip portion of the punch and a second elongated projection or a second elongated groove provided on an upper surface of the cutting blade.

9. The punch for press working according to claim 8, wherein a contact surface between the tip portion of the punch and the cutting blade is adhered by roll bonding or an anaerobic adhesive.

10. The fitting of the first elongated groove or the first elongated protrusion and the second elongated protrusion or the second elongated groove is an inverted "H" shaped or "H" shaped dovetail joint. The punch for press working according to claim 8.

11. The fitting of the first elongated groove or the first elongated protrusion and the second elongated protrusion or the second elongated groove is wedge-shaped. The punch for press working according to claim 10.

12. A press working apparatus, comprising the punch for press working according to any one of claims 1 to 11.

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