Stamping processing tool and processing method thereof

Abstract

To provide a stamping processing tool capable of easily processing a coin or the like formed with an uneven pattern with a simple mechanism, and a processing method of the stamping processing tool.SOLUTION: A stamping processing tool 1 according to the present invention includes: a head part 20 having one end to which a striking part 10 is detachably attached; a handle part 30 fixed to the head part 20; and a pair of mold members 40a and 40b forming an uneven pattern in at least one surface of a workpiece 2. The head part 20 is formed with a storage part 21 storing the workpiece 2 in a state of being held by the mold members 40a and 40b. The striking part 10 is attached to the head part 20 in a state of being in contact with stored one mold member 40b.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an embossing tool for forming a concavo-convex pattern on at least one side of a workpiece and a processing method thereof.

Background Art

[0002] Conventionally, a die member has been impressed on both sides of a disk-shaped metal material to process it into a coin having a concavo-convex pattern. In addition to coins, similar products such as medals and currencies are also manufactured by the same processing.

[0003] For example, in Patent Document 1, a pair of upper and lower opposing punches for sandwiching a material are inserted into a central hole formed inside a forging device, and a medal or a currency is manufactured by pressing an electrode pattern surface formed on the punch against the material by a press machine. Further, in Patent Document 2, an operation lever is manually operated to bring an engraving into contact with a workpiece, and a spring member for urging a hammer member is set in a compressed state. By releasing the engagement between the hammer member and the trigger, a device for striking an engraving holder with the hammer member to engrave characters or the like on the workpiece is described.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1 described above, since medals or coins are manufactured using a press machine, the manufacturing process is complex, the manufacturing cost burden is large, and there is a problem that small-scale production is difficult. In Patent Document 2, since a work can be manually engraved, small-scale production is possible. However, as described in Patent Document 1, imprinting and processing both sides of the work are not assumed, and it is difficult to process coins or the like with a small amount and easily formed uneven patterns.

[0006] Therefore, an object of the present invention is to provide a stamping tool and a processing method thereof that can easily process coins or the like with uneven patterns formed by a simple mechanism.

Means for Solving the Problems

[0007] The stamping tool according to the present invention includes a head portion to which a striking portion is detachably attached at one end, a handle portion fixed to the head portion, and a pair of die members for forming an uneven pattern on at least one surface of a workpiece. The head portion is formed with a housing portion for housing the workpiece in a state of being sandwiched between the die members. The striking portion is attached to the head portion in a state of abutting against one of the housed die members. Further, the housing portion is formed in a cylindrical shape with an opening on the side of the striking portion, and the die member is housed so as to be movable in the axial direction of the housing portion in a state of sandwiching the workpiece. Further, the striking portion includes a striking member for striking a processing table, and a transmission member having one end fixed to the striking member and the other end side housed in the housing portion and set in a state of being in close contact with one of the die members. Further, a lid member having a mounting hole for detachably inserting the transmission member is provided, and by attaching the lid member to the head portion in a state where the transmission member is inserted into the mounting hole, the other end side of the transmission member is housed in the housing portion and set in a state of being in close contact with one of the die members. Further, a movable member is housed in the housing portion so as to be movable in the axial direction in a state of abutting against the other die member and the bottom surface. Further, a weight for reducing impact is attached to the other end of the head portion.

[0008] The stamping method according to the present invention accommodates a workpiece in a housing portion formed in a head portion to which a handle portion is attached, while sandwiching the workpiece with a pair of die members, attaches a striking portion to one end of the head portion, and sets the striking portion in a state of abutting against one of the die members that houses the striking portion, and forms a concavo-convex pattern on at least one surface of the workpiece by applying an impact force to the striking portion with the die member.

Effect of the Invention

[0009] Since the present invention has the above-described configuration and is set such that a striking portion abuts against one of the die members while the workpiece is sandwiched between the pair of die members, by applying an impact force to the striking portion, the die member can be impressed on the workpiece to form a concavo-convex pattern on at least one surface of the workpiece.

[0010] Then, by gripping the handle portion by hand and striking the striking portion against a metal workbench with a striking operation similar to that of an ordinary hammer, it becomes possible to easily perform stamping on a coin or the like having a concavo-convex pattern with a simple mechanism.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are preferred specific examples for implementing the present invention, and thus various technical limitations are imposed. However, the present invention is not limited to these forms unless specifically stated to limit the present invention in the following description.

[0013] FIG. 1 is an external perspective view of an embodiment of a stamping tool according to the present invention, and FIG. 2 is a front view of the stamping tool. Further, FIG. 3 shows a cross-sectional view taken along line A-A of FIG. 1.

[0014] The stamping tool 1 includes a head portion 20 to which a striking portion 10 is detachably attached at one end, and a handle portion 30 fixed to the head portion 20. In a cylindrical accommodating portion 21 formed inside the head portion 20, a pair of die members 40a and 40b for forming uneven patterns on at least one side of the workpiece 2 are accommodated. And, as will be described later, the striking portion 10 is attached to the head portion 20 in a state of being in contact with one of the die members 40a. In the following description, the side to which the striking portion 10 of the stamping tool 1 is attached will be described as the front end side, and the opposite side will be described as the rear end side.

[0015] The workpiece 2 to be processed may be any material used for stamping. For example, metal materials such as gold, silver, copper, aluminum, tin, zinc, iron, nickel, and alloy materials (such as stainless steel and brass) containing at least one of these can be mentioned. The shape of the workpiece 2 is, for example, a circular shape formed in a plate shape with a predetermined thickness, but is not particularly limited. In addition to a circular shape, an elliptical shape may be used, and various shapes such as polygonal shapes such as triangles and quadrilaterals, and oval shapes can be used.

[0016] The striking part 10 includes a striking member 11 for striking the processing table, a transmission member 12 having one end fixed to the striking member 11 and the other end side accommodated in the accommodating part 21 and set to be in close contact with one mold member 40b, and a lid member 13 formed with a mounting hole 13a for detachably inserting the transmission member 12 and detachably attached to the head part 20.

[0017] In this example, the striking member 11 is formed in a columnar shape with the corners of the tip end rounded and chamfered. A mounting hole is formed through the center part of the striking member 11 along the axial direction, with a mounting hole 11a of a small diameter formed on the tip end side and a mounting hole 11b of a large diameter formed on the rear end side.

[0018] The transmission member 12 is formed in a substantially columnar shape with a smaller diameter than the striking member 11, and a tapered insertion part 12a is formed on the tip end side. A screw hole is drilled through the center part of the insertion part 12a along the axial direction. With the insertion part 12a inserted into the mounting hole 11b, a fixing screw member 14 is inserted from the mounting hole 11a and screwed into the screw hole, so that the striking member 11 is fixed to the tip end part of the transmission member 12.

[0019] A fitting part 12b that is detachably fitted into the accommodating part 21 is formed on the rear end side of the transmission member 12. The rear end face of the fitting part 12b is formed in a planar shape so as to be in full contact with the front end face of the mold member 40b. A flange-shaped engaging part 12c that engages with the lid member 13 is formed so as to protrude from the outer peripheral surface on the tip end side of the fitting part 12b.

[0020] The lid member 13 is formed to cover the opening of the accommodating part 21 on the tip end side of the head part 20. In this example, an annular mounting part 13b extending rearward with a predetermined width over the entire circumference is integrally formed on the periphery of a disk-shaped contact part 13a having a larger diameter than the cylindrical part 22 on the tip end side of the head part 20. A mounting hole 13c for detachably inserting the fitting part 12b of the transmission member 12 is formed to penetrate through the center of the contact part 13a, and a step part 13d that engages with the engaging part 12c of the transmission member 12 is formed over the entire circumference on the peripheral edge on the rear end side of the mounting hole 13c.

[0021] In this example, a thread groove is formed on the inner peripheral surface of the mounting portion 13b, and is screwed onto the thread formed on the outer peripheral surface of the cylindrical portion 22 of the head portion 20 so that the lid member 13 is fastened and fixed to the head portion 20.

[0022] The head portion 20 has a shape in which the tip side is formed in a cylindrical shape and the rear end side is continuously formed in a prismatic shape. On the outer peripheral surface of the cylindrical portion 22 on the tip side, a thread is formed. Inside the head portion 20, a cylindrical accommodating portion 21 with an open tip is formed in the axial direction toward the rear end side. In this example, the accommodating portion 21 is formed in a substantially cylindrical shape corresponding to a substantially disc-shaped mold member. Note that the shape of the accommodating portion 21 may be formed according to the shape of the mold member and is not particularly limited.

[0023] On the rear end side of the head portion 20, a mounting hole 23 is formed so as to penetrate in a direction orthogonal to the axial direction of the head portion 20. The tip portion of the handle portion 30 is inserted into the mounting hole 23 from one opening, and a fixing screw is inserted from the other opening. The screw is screwed into the fixing screw hole formed at the tip portion of the handle portion 30 so that the handle portion 30 is fixed to the rear end side of the head portion 20.

[0024] Also, an opening 24 communicating with the accommodating portion 21 is formed on the side surface of the rear end side of the head portion 20. A jig is inserted into the accommodating portion 21 through the opening 24 so that the mold member accommodated in the accommodating portion 21 can be pushed out toward the tip side, and the mold member can be easily taken out of the accommodating portion 21.

[0025] The handle portion 30 is formed as a rod-shaped body having a predetermined length, and is set to a length that can be easily grasped by hand and easily swung down in the same manner as a normal hammer.

[0026] In this example, the mold members 40a and 40b are formed in a substantially disc shape, and a concavo-convex pattern is formed on the surface facing the workpiece 2. When forming a concavo-convex pattern on only one side of the workpiece 2, a concavo-convex pattern may be formed on the surface of one of the mold members facing it, and the surface of the other mold member may be formed as a flat surface.

[0027] Inside the accommodating portion 21, a movable member 41 is detachably accommodated on the rear end side of the die member 40a. The movable member 41 is formed in a substantially cylindrical shape, and the entire front end surface is adapted to contact the rear end surface of the die member 40a. The rear end side of the movable member 41 is formed in a tapered shape and is substantially frustoconical, and the rear end surface with a small diameter is adapted to contact the bottom surface (the end surface on the rear end side) inside the accommodating portion 21. The outer diameter of the movable member 41 is set to be the same as or slightly smaller than the inner diameter of the accommodating portion 21, and it is set to be movable only in the axial direction in a state where its side peripheral surface contacts the inner peripheral surface of the accommodating portion 21.

[0028] The die members 40a and 40b are detachably positioned inside the accommodating portion 21 and are set to be movable only in the axial direction without displacement or rotation. For example, a pair of convex portions are formed along the axial direction at opposing positions on the outer peripheral surfaces of the die members 40a and 40b, and concave portions are formed along the axial direction at positions corresponding to the convex portions on the inner peripheral surface of the accommodating portion 21. By fitting the convex portions of the die members 40a and 40b into the concave portions in a state of close contact and then fitting them into the accommodating portion 21, displacement and rotation can be prevented and they can be set to be movable in the axial direction. In this case, concave portions may be formed on the outer peripheral surfaces of the die members 40a and 40b and convex portions may be formed on the inner peripheral surface of the accommodating portion 21.

[0029] Also, by setting the outer diameters of the die members 40a and 40b to be slightly smaller than the inner diameter of the accommodating portion 21, a slight gap is formed between the outer peripheral surfaces of each die member and the inner peripheral surface of the accommodating portion 21 other than the fitting portions of the above-described concave and convex portions, and it can be set to allow deformation due to the impact of each die member and the sandwiched workpiece.

[0030] The striking part 10 and the head part 20 can be formed by processing a metal material. Examples of the metal material include iron-based materials such as stainless steel and carbon steel, and metal materials for mechanical structures are preferred. Similarly, the die member and the movable member can also be formed by processing a metal material, and uneven patterns can be formed on the die-striking surface of the die member by three-dimensional processing or the like. Further, the handle part 30 can be formed by processing a high-strength and lightweight material such as a metal material into a rod shape.

[0031] FIG. 4 is an exploded view of the die-striking tool 1. The upper end portion of the handle part 30 is inserted into the mounting hole 23 on the rear end side of the head part 20, and the screw member 25 is attached to the mounting hole 23 and screwed into the screw hole formed in the upper end portion of the handle part 30 to fix the handle part 30 to the head part 20.

[0032] The movable member 41 is inserted into the accommodating part 21 with the end side formed in a tapered shape set to the rear end side. Since the outer diameter of the movable member 41 is set to be substantially the same as or slightly smaller than the inner diameter of the accommodating part 21, the movable member 41 is inserted in the axial direction without rattling in the radial direction.

[0033] Next, the die member 40a is inserted into the accommodating part 21 with the fitting part aligned. In this example, the inner diameter of the accommodating part 21 slightly expands from the position where the die member 40a is arranged, and a slight gap is formed between the outer peripheral surface of the die member 40a and the inner peripheral surface of the accommodating part 21 except for the fitting part. After the die member 40a is inserted, the workpiece 2 and the die member 40b are inserted and set in a state where the workpiece 2 is clamped by the pair of die members 40a and 40b.

[0034] The transmission member 12 is set in a state where the insertion part 12a is inserted into the mounting hole 13c of the lid member 13 and the engaging part 12c is engaged with the stepped part 13d in advance. Then, the striking member 11 is attached to the insertion part 12a, and the striking member 11 is fixed to the transmission member 12 by the screw member 14.

[0035] After inserting the fitting portion 12b of the transmission member 12 to which the striking member 11 is fixed into the accommodating portion 21, the attachment portion 13b of the lid member 13 is screwed and fixed around the columnar portion 22 of the head portion 20, thereby setting the transmission member 12 in a state of abutting against the mold member 40b. Since the engaging portion 12c of the transmission member 12 is engaged with the stepped portion 13d of the lid member 13, by fixing the lid member 13 to the head portion 20, it is set in a state where it can move only on the rear end side.

[0036] Since the mold members 40a and 40b, the work material 2, and the movable member 41 are accommodated so as to be movable in the axial direction, by fixing the lid member 13 to the head portion 20, it is set in a state where it can move to the rear end side together with the transmission member 12 and is in close contact with each other.

[0037] In the state where each member is attached, the central axes of each member of the striking member 11, the transmission member 12, the mold members 40a and 40b, and the movable member 41 are set to substantially coincide with the central axis of the accommodating portion 21.

[0038] FIG. 5 is an explanatory view regarding the stamping operation. By gripping the handle portion 30 by hand and dropping the stamping tool 1, and striking the upper surface of the metal processing table 100 with the striking portion 10, an impact force is applied to the striking member 11.

[0039] The impact force applied to the striking member 11 generates a momentary large force directed toward the rear end side with respect to the mold member 40b via the transmission member 12. The force applied to the mold member 40b comes to be applied to the mold member 40a and the work material 2 simultaneously.

[0040] Also, a force directed toward the rear end side is applied to the movable member 41, but the rear end surface of the movable member 41 collides with the bottom surface in the accommodating portion 21 to generate a repulsive force, and a force directed toward the front end side is applied to the mold member 40a. Between the transmission member 12 and the movable member 41, a stamping action is performed in which the mold members 40a and 40b are impressed on both surfaces of the work material 2 by the applied impact force.

[0041] In this example, since the rear end side of the movable member 41 is formed in a frustum of a cone shape and the collision surface is set to concentrate on the central portion, the repulsive force due to the collision reaches the entire rear end surface of the die member 40a, and a uniform die-casting action over the entire die surface can be surely performed.

[0042] And by appropriately repeating such striking operations, the desired concavo-convex patterns can be clearly exhibited on both surfaces of the workpiece 2.

[0043] FIG. 6 is an external perspective view of another embodiment of the die-casting tool, and FIG. 7 is an exploded view of the die-casting tool shown in FIG. 6. In this example, there is no movable member inserted into the accommodating portion in the embodiment shown in FIG. 1, and a weight is attached to the rear end side of the head portion.

[0044] The die-casting tool 1' has a striking portion 10' detachably attached to the front end side of the head portion 20', and a weight 50 detachably attached to the rear end side. Further, one end portion of a handle portion 30' is inserted into a mounting hole 23' penetrating in a direction orthogonal to the axial direction in the head portion 20' and fixed by a screw member 25'.

[0045] Inside the head portion 20', a cylindrical accommodating portion 21' opening to the front end side is formed. And inside the accommodating portion 21', the workpiece 2' is accommodated in a state of being sandwiched by a pair of die members 40a' and 40b', and the end surface of the die member 40a' on the rear end side is in contact with the bottom surface (the rear end side end surface) inside the accommodating portion 21'.

[0046] The striking portion 10' includes a striking member 11', a transmission member 12' and a lid member 13'. Similar to the embodiment shown in FIG. 1, the front end side of the transmission member 12' is inserted into the mounting hole of the lid member 13', and the striking member 11' is fixed to the front end portion by a screw member 14'. Then, the lid member 13' is fitted and screwed onto the outer peripheral surface of a columnar portion 22' formed on the front end side of the head portion 20' so as to fix the striking portion 10' to the front end side of the head portion 20'. In a state where the striking portion 10' is fixed, the rear end surface of the transmission member 12' is set to be in contact with the end surface of the die member 40b'.

[0047] In the state where each member is attached, the central axes of each member of the striking member 11’, the transmission member 12’, and the die members 40a’ and 40b’ are set to substantially coincide with the central axis of the accommodating portion 21’.

[0048] In this example, a tubular spacer 21a’ is inserted in accordance with the inner peripheral surface of the accommodating portion 21’. And the inner diameter of the spacer 21a’ is adjusted to be the same as or slightly larger than the outer diameters of the die members 40a’ and 40b’, preventing displacement and rotation of the die members and enabling movement only in the axial direction. Further, by forming a concave portion along the axial direction on the inner peripheral surface of the spacer 21a’ and forming a convex portion that fits into the concave portion on the outer peripheral surface of the die member, the die member can be surely set to be movable only in the axial direction.

[0049] By preparing a plurality of types of spacers whose sizes are adjusted according to the inner diameter of the accommodating portion and the outer diameter of the die member, and appropriately selecting a spacer corresponding to die members of various sizes, it is possible to perform die forging on workpieces of a plurality of types of sizes with one die forging tool.

[0050] On the rear end side of the head portion 20’, a rod-shaped attachment portion 26 projects axially, and a thread is formed on the tip end portion of the attachment portion 26. The columnar weight body 50 has the attachment portion 26 inserted into the attachment hole 50a formed in the center thereof, and the nut member 51 is screwed and fixed to the tip end portion of the attachment portion 26. A pair of anti-loosening screw members 52 are fastened and fixed to the nut member 51.

[0051] By attaching the weight body 50 to the rear end side of the head portion 20’, the balance with the striking portion 10’ attached to the front end side is improved, and the operability of the die forging tool becomes good. Also, when the die forging tool 1’ is swung down and the striking portion 10’ is made to collide with the processing table, the repulsive force of the head portion 20’ is suppressed, the impact is reduced, and a stable die forging operation can be performed.

Example

[0052] The head part, the striking part, and the handle part of the stamping tool shown in FIG. 1 were formed by cutting a carbon steel material.

[0053] The head part has an outer diameter of 55 mm and a length of 107 mm, and a receiving part with an inner diameter of 30 mm (32 mm for the concave part) and a depth of 27 mm is formed inside. The striking part has an outer diameter of 55 mm and a length of 35 mm for the striking member, and an outer diameter of 30 mm and a length of 35 mm for the transmission member.

[0054] A pair of stamping members were formed from a bearing steel material with an outer diameter of 30 mm (32 mm for the convex part) and a thickness of 10 mm, and an uneven pattern was applied to the stamping surface by three-dimensional processing. As the workpiece, a disc-shaped one made of a brass material with an outer diameter of 29.4 mm and a thickness of 2.5 mm was used.

[0055] As described with reference to FIG. 4, after the movable member, the die member, and the workpiece were accommodated in the receiving part of the head part, the striking part and the handle part were attached to the head part to assemble the stamping tool. The weight of the assembled stamping tool was about 2 kg.

[0056] The handle part of the stamping tool was grasped by hand and swung down toward the processing table (made of carbon steel material, with an outer diameter of 250 mm and a thickness of 50 mm) to cause the striking part to collide. FIG. 8 is an image of the stamped surface of the workpiece.

[0057] As shown in FIG. 8, it was confirmed that a complex uneven pattern was clearly shown in detail on the stamped surface, and it was found that uniform stamping processing was performed without unevenness over the entire surface. It was confirmed that a sufficient force was generated for the stamping action of pressing the die member against the workpiece by the impact force of swinging down the head part onto the processing table.

Explanation of Signs

[0058] 1... type of forging tool, 2... workpiece, 10... striking part, 11... striking member, 12... transmission member, 13... cover member, 14... screw member, 20... head part, 21... accommodating part, 22... cylindrical part, 23... mounting hole, 24... opening, 25... screw member, 26... mounting part, 30... handle part, 40a, 40b... die members, 41... movable member, 50... hammer body, 51... nut member, 52... screw member

Claims

1. A die stamping tool comprising: a head portion having a striking portion detachably attached to one end; a handle portion fixed to the head portion; and a pair of die members for forming a concavo-convex pattern on at least one surface of a workpiece. The head portion has a receiving portion for receiving the workpiece in a state of being clamped by the die members. The striking portion is a die stamping tool attached to the head portion in a state of abutting against one of the received die members.

2. The receiving portion is formed in a cylindrical shape with an opening on the side of the striking portion. The die member is received so as to be movable in the axial direction of the receiving portion in a state of clamping the workpiece. The die stamping tool according to claim 1.

3. The striking portion includes a striking member for striking a processing table, and a transmission member having one end fixed to the striking member and the other end side received in the receiving portion and set to be in close contact with one of the die members. The die stamping tool according to claim 1 or 2.

4. The die stamping tool according to claim 3, further comprising a lid member having a mounting hole for detachably inserting the transmission member. By attaching the lid member to the head portion with the transmission member inserted into the mounting hole, the other end side of the transmission member is received in the receiving portion and set to be in close contact with one of the die members.

5. In the receiving portion, a movable member is received so as to be axially movable in a state of abutting against the other die member and the bottom surface. The die stamping tool according to claim 1 or 2.

6. The head portion has a weight attached to the other end for reducing impact. The die stamping tool according to claim 1 or 2.

7. A die stamping method, comprising: receiving a workpiece in a receiving portion formed in a head portion to which a handle portion is attached, in a state of being clamped by a pair of die members; attaching a striking portion to one end of the head portion and setting the striking portion to abut against one of the received die members; and applying an impact force to the striking portion to form a concavo-convex pattern on at least one surface of the workpiece by the die members.

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