JP2022061880A - Scrap coining method and shear processing device - Google Patents

Abstract

To provide a scrap coining method capable of suppressing cost increase of a shear processing device which is used for scrap coining.SOLUTION: A scrap coining method is configured to use a shear processing device 10 for shearing a workpiece 20 by a die 12 and punching for producing a product 22, support the product 22 between the die 12 and a holder 14, arrange as a scrap 24, a part separated from the workpiece 20 by shearing, on a tip end part 18B of a counter punch 18, move the counter punch 18 toward the product 22 side in a state of arranging the scrap 24 on the upper side, then bring an outer edge of the scrap 24 into contact with an end face of the supported product 22 for folding and deforming the outer edge of the scrap 24, thereby coining.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to scrap coining methods and shearing equipment.

Conventionally, when shearing to obtain a processed material (product) by shearing the work material (steel plate), scrap generated by partial punching of the steel plate or cutting of the end is used as a coining punch without discarding it. The scrap coining method to do is known.

For example, Patent Document 1 describes a scrap coining method in which the end face of a punched material punched from a workpiece using a shearing device is brought into contact with the end face of the sheared surface of the processed material (product) on a die and rubbed against each other. Have been described. Hereinafter, the process including the scrap coining method is also simply referred to as “coining”. Patent Document 1 states that a steel sheet having a sheared surface having excellent hydrogen embrittlement resistance and fatigue strength can be manufactured by coining.

International Publication No. 2016/136909

Here, when the product obtained from a relatively high-strength steel plate and the scrap are rubbed against each other, the load generated between the product and the scrap during coining becomes large. When the load at the time of coining becomes large, in order to reduce the burden on the shearing machine side that receives the load, it is necessary to bear the burden of additional capital investment such as increasing the capacity of the impact mitigation device such as gas cushion, and shearing. The problem arises that the cost of the processing equipment increases.

In view of the above problems, it is an object of the present disclosure to provide a scrap coining method capable of suppressing an increase in the cost of a shearing machine used for scrap coining, and a shearing machine.

In the scrap coining method according to the first aspect of the present disclosure, the die, the holder sandwiching the work material between the dies, the punch arranged with a clearance between the dies, and the punch facing each other. Using a shearing device equipped with a counter punch, the work piece is sheared by a die and a punch to form a product, the product is supported between the die and the holder, and by shearing. The part separated from the work material is placed on the tip of the counter punch as scrap, and the counter punch is moved toward the product side with the scrap placed on the upper side, and the outer edge of the scrap is supported. By contacting the end face of the scrap, the outer edge of the scrap is bent and deformed while shearing.

In the first aspect, when the counter punch is moved toward the product side after shearing, the outer edge of the scrap is bent and deformed when the scrap is coined in contact with the end face of the product. Due to the bending deformation, the load generated between the product and the scrap during coining is absorbed, so that the load on the shearing machine side that receives the load is reduced. Therefore, there is no need to increase the capacity of the impact mitigation device such as a gas cushion.

The shearing apparatus according to the second aspect of the present disclosure faces a die, a holder that sandwiches the work material between the dies, a punch arranged with a clearance between the dies, and the punch. It is provided with a base portion and a counter punch provided on the workpiece side of the base portion and having a tip portion having a diameter reduced from the base portion.

In the second aspect, as in the first aspect, the load generated between the product and the scrap during coining is absorbed by the bending deformation of the outer edge of the scrap, so that the load on the shearing machine side that receives the load is reduced. Will be done. Therefore, there is no need to increase the capacity of the impact mitigation device such as a gas cushion. Further, the counter punch has a tip portion whose diameter is reduced from the base portion, and scrap is arranged on the upper side of the tip portion. Therefore, compared to the case of coining in which the tip portion has the same diameter as the base portion and the upper surface of the tip portion is flat, the outer edge of the scrap is smoothed along the shape of the reduced diameter tip portion during coining. Can be bent and deformed.

According to the present disclosure, it is possible to provide a scrap coining method capable of suppressing an increase in the cost of a shearing machine used for scrap coining, and a shearing machine.

It is sectional drawing explaining the structure of the shearing processing apparatus which concerns on embodiment of this disclosure. 2A to 2F are perspective views illustrating various patterns applicable as the superstructure of the counter punch of the shearing apparatus according to the present embodiment. It is sectional drawing explaining the shearing processing method using the shearing processing apparatus which concerns on this Embodiment when the outer edge of scrap protrudes to the outside of the base of a counter punch (the 1). It is sectional drawing explaining the shearing processing method using the shearing processing apparatus which concerns on this Embodiment when the outer edge of scrap protrudes to the outside of the base of a counter punch (the 2). It is sectional drawing explaining the shearing processing method using the shearing processing apparatus which concerns on this Embodiment when the outer edge of a scrap is located inside the base of a counter punch (the 1). FIG. 2 is a cross-sectional view illustrating a shearing method using the shearing apparatus according to the present embodiment when the outer edge of the scrap is located inside the base of the counter punch (No. 2). It is sectional drawing explaining the shearing processing method using the shearing processing apparatus which concerns on a comparative example (the 1). It is sectional drawing explaining the shearing processing method using the shearing processing apparatus which concerns on a comparative example (the 2). It is sectional drawing explaining the structure of the shearing processing apparatus which concerns on the modification of this Embodiment. It is sectional drawing explaining another pattern applicable as the superstructure of the counter punch of the shearing machine which concerns on the modification. FIG. 11A is a graph illustrating the relationship between the protrusion ratio D / L and the maximum load P during coining in Example 1, and FIG. 11B is a graph showing the protrusion ratio D in Example 1. It is a graph explaining the relationship between / L and the reduction amount Δσ of the residual stress. FIG. 12A is a graph illustrating the relationship between the protrusion ratio D / L and the maximum load P during coining in Example 2, and FIG. 12B is a graph showing the protrusion ratio D in Example 2. It is a graph explaining the relationship between / L and the reduction amount Δσ of the residual stress. FIG. 13 (A) is a graph illustrating the relationship between the protrusion ratio D / L and the maximum load P during coining in Example 3, and FIG. 13 (B) is a graph showing the protrusion ratio D in Example 3. It is a graph explaining the relationship between / L and the reduction amount Δσ of the residual stress. FIG. 14 (A) is a graph illustrating the relationship between the protrusion ratio D / L and the maximum load P during coining in Example 4, and FIG. 14 (B) is a graph showing the protrusion ratio D in Example 4. It is a graph explaining the relationship between / L and the reduction amount Δσ of the residual stress. FIG. 15A is a graph illustrating the relationship between the protrusion ratio D / L and the maximum load P during coining in Example 5, and FIG. 15B is a graph showing the protrusion ratio D in Example 5. It is a graph explaining the relationship between / L and the reduction amount Δσ of the residual stress. FIG. 16A is a graph illustrating the relationship between the protrusion ratio D / L and the maximum load P during coining in Example 6, and FIG. 16B is a graph showing the protrusion ratio D in Example 6. It is a graph explaining the relationship between / L and the reduction amount Δσ of the residual stress. FIG. 17A is a graph illustrating the relationship between the protrusion ratio D / L and the maximum load P during coining in Example 7, and FIG. 17B is a graph showing the protrusion ratio D in Example 7. It is a graph explaining the relationship between / L and the reduction amount Δσ of the residual stress. FIG. 18A is a graph illustrating the relationship between the protrusion ratio D / L and the maximum load P during coining in Example 8, and FIG. 18B is a graph showing the protrusion ratio D in Example 8. It is a graph explaining the relationship between / L and the reduction amount Δσ of the residual stress. It is a graph which explains the relationship between the diameter-thickness ratio W / T and the reduction amount Δσ of the residual stress in Example 9 to Example 11 in the case of D <0.

This embodiment will be described below. In the description of the drawings below, the same parts and similar parts are designated by the same reference numerals or similar reference numerals. However, the relationship between the thickness and the plane dimension in the drawing, the ratio of the thickness of each device and each member, etc. are different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following explanation. In addition, there are parts where the relationships and ratios of the dimensions of the drawings are different from each other.

<Structure of shearing equipment>
As shown in FIG. 1, the shearing apparatus 10 according to the present embodiment is, for example, a hydraulic press machine that is arranged in a steel mill and can perform piercing processing by punching a workpiece 20 to form a circular hole. be. The shearing apparatus 10 includes a die 12, a holder 14, a punch 16, and a counter punch 18.

The shearing apparatus 10 has a clearance 15 between the inner surface of the die 12 and the outer surface of the punch 16 and the outer surface of the counter punch 18. FIG. 1 illustrates a state in which a clearance 15 having a constant width L is formed between the position A1 on the inner surface of the die 12 and the position A2 on the outer surface of the counter punch 18. The clearance 15 is determined by the product of the thickness T of the work material 20 and the clearance ratio preset according to the desired processing quality.

A moving device (not shown) is connected to the punch 16 and the counter punch 18, respectively. The moving device can be realized by, for example, an electric motor, a hydraulic pressure mechanism, or the like. By the moving device, the die 12 and the punch 16 can move independently and relative to each other along the direction orthogonal to the horizontal plate surface of the workpiece 20 (vertical direction in FIG. 1).

The work material 20 is a steel plate which is a metal material in the present embodiment. In the present disclosure, the work material 20 is not limited to the metal material, and any material such as wood or resin material can be adopted. The work material 20 has a certain thickness T and is sandwiched horizontally between the die 12 and the holder 14 before punching. In this embodiment, "high strength" means that the tensile strength of the steel sheet is about 980 MPa or more. The definition of the tensile strength of the steel sheet is based on, for example, "ISO 6892-1: 2009".

FIG. 1 illustrates a state in which the work material 20 is separated into a product 22 and a scrap 24 immediately after the work material 20 is punched and before coining. In the present embodiment, the holes of the die are substantially circular in a plan view, and the diameter W of the punched holes, which is the diameter of the holes of the die (distance between the dies in the left-right direction in FIG. 1), and the scrap 24. It is the same as the diameter (diameter). Therefore, the radius RS of the scrap 24 before coining is half the diameter W of the punched hole (diameter W of the scrap 24 before coining).

The holder 14 is arranged on the die 12 and sandwiches the work material 20 with the die 12. The punch 16 is a columnar punching member, and is arranged on the upper side of the workpiece 20 in FIG. 1 before punching. The punch 16 descends from above with respect to the work material 20 in the portion not sandwiched between the die 12 and the holder 14, and punches the work material 20 into a circular shape.

(Counter punch)
The counter punch 18 is a columnar pushing member, and before punching, the counter punch 18 faces the punch 16 on the same straight line along the moving direction of the punch 16 under the workpiece 20 in FIG. Have been placed. The counter punch 18 has a base portion 18A and a tip portion 18B provided on the workpiece 20 side of the base portion 18A. At the time of punching, the scrap 24 is formed by punching the punch 16, and the formed scrap 24 is placed on the tip portion 18B of the counter punch 18 located on the lower side. Further, after punching, the counter punch 18 pushes the scrap 24 toward the upper side in FIG. 1, so that coining is performed.

(base)
In this embodiment, the diameter of the base 18A of the counter punch 18 and the diameter of the punch 16 are the same. Therefore, the radius RCP of the base 18A and the radius of the punch 16 are the same. In FIG. 1, the upper part of the columnar shape of the base 18A is partially exemplified, and the shape of the lower part is omitted. The shape of the lower portion of the base portion 18A may be columnar like the upper portion, or may be wider or reduced in diameter from the upper portion. The shape of the lower part of the base 18A is arbitrary as long as it holds as a counter punch 18.

(Tip)
The tip portion 18B is a spherical (dome-shaped) region provided in the upper part of the counter punch 18, and is directed from the base portion 18A side (lower side in FIG. 1) to the workpiece 20 side (upper side in FIG. 1). It is curved in an arc shape so as to gradually reduce its diameter. The reduced diameter portion of the tip 18B facilitates bending of the outer edge of the scrap 24 during coining.

The apex B of the tip portion 18B in FIG. 1 is the uppermost portion of the counter punch 18 and is in contact with the lower surface of the scrap 24. In the present embodiment, a line that passes through the apex B and is perpendicular to the horizontal plate surface of the workpiece 20 is defined as the reference line C. Further, in the present embodiment, the reference line C is a central axis line passing through the center of the bottom circle of the cylinder of the counter punch 18. The shape of the upper portion of the counter punch 18 of the present embodiment including the base portion 18A and the tip portion 18B is rotationally symmetric with respect to the reference line C. In the present embodiment, the distance between the contact point with the scrap 24 (vertex B) and the outer surface of the counter punch 18 is the same as the radius RCP of the base 18A.

In the present disclosure, the holes (punched holes) of the product are not limited to a perfect circle in a plan view, and may be a distorted circular shape such as an ellipse or a broad bean. Even if the hole (punched hole) of the product has a distorted circular shape, the area between the contact point between the tip portion 18B and the scrap 24 and the outer surface of the base portion 18A is reduced in diameter, and the cross-sectional view shows. The tip portion 18B may have a height H so that a certain distance is formed.

The tip portion 18B has a constant height H. The tip portion 18B in FIG. 1 has a relatively flat shape, but the shape of the tip portion 18B of the counter punch 18 of the present disclosure is not limited to this, and the outer edge of the scrap 24 can be bent. As long as it is, it can be changed as appropriate.

As another shape of the tip portion of the present disclosure, for example, as shown in FIG. 2A, the tip portion 18B may have a spherical shape in which the radius RS and the height H of the scrap 24 are equal to each other. In other words, the shape of the tip portion 18B in FIG. 2A is spherical, and the radius of curvature of the tip portion 18B is smaller than the radius of curvature of the reduced diameter portion of the tip portion 18B in FIG.

Further, as shown in FIG. 2B, the tip portion 18B may have a flat upper surface. In other words, in the shape of the tip portion 18B in FIG. 2 (B), the upper portion of the sphere head is cut out to form a flat upper surface. The surface of the region between the top surface and the base 18A is curved and has a smaller diameter than the base 18A.

Further, as shown in FIG. 2C, the tip portion 18B may be conical and the tip portion 18B may be pointed upward. That is, the surface of the tip portion 18B is not an arc-shaped curved surface but a linear inclined surface in a cross-sectional view. In the present disclosure, the shape of the tip portion 1 that is pointed toward the upper side is not limited to a conical shape, and may be another geometric shape such as a pyramid shape.

Further, as shown in FIG. 2D, the tip portion 18B may have a truncated cone shape having a flat upper surface including the apex B. The surface of the region between the top surface and the base 18A is tapered and gradually reduced in diameter from the base 18A. Further, as shown in FIG. 2E, the tip portion 18B may be a columnar shape having a diameter reduced from that of the columnar base portion 18A.

Further, as shown in FIG. 2F, the tip portion 18B may be formed by superimposing a plurality of cylindrical portions. The plurality of cylindrical portions are arranged so as to have a smaller diameter toward the upper side. The number of superposed cylindrical portions can be set arbitrarily. Even if the tip portion 18B has a plurality of cylindrical portions formed in a stepped shape by superposition as in the tip portion 18B of FIG. 2 (F), the diameter is gradually reduced toward the upper side, and the diameter is gradually reduced. At that time, the outer edge of the scrap 24 can be bent.

<Scrap coining method>
Next, a scrap coining method using the shearing apparatus 10 according to the present embodiment will be described with reference to FIGS. 3 to 6. First, before punching, the work material 20 is sandwiched and supported by the die 12 and the holder 14. Further, the counter punch 18 is in contact with the work material 20, and a predetermined pressure (back pressure) is applied to the work material 20.

In each of the scrap coining methods of the present embodiment described below, as an operation at the time of coining, a case where the scrap 24 is pressed against the product 22 and the scrap 24 is pushed until it penetrates the upper side of the product 22 is exemplified. ing. However, in the coining of the present disclosure, the operation of pressing the scrap against the product and pushing it until it penetrates upward is not essential. For example, from the surface (lower surface) of the work material on the die side to the height of the boundary between the sheared surface and the fracture surface, to a certain area where a partial height is formed on the end face of the work material. , Scrap may be pushed in.

The effect of reducing residual stress can be obtained even by coining the operation of partially pushing the scrap into the product without penetrating the upper side of the product. When the scrap is not penetrated, it may not be required to strictly align the position of the scrap arranged on the counter punch with the position of the punched hole as compared with the case of penetrating the scrap. In this case, it is not necessary to apply a predetermined pressure to the work material by bringing the counter punch into contact with the work material before punching.

Next, the moving device is operated to lower the punch 16, and the work material 20 is punched out by the die 12 and the punch 16 to form the product 22. The formed product 22 is supported between the die 12 and the holder 14. On the other hand, the portion separated from the work material 20 becomes scrap 24. As shown in FIG. 1, the scrap 24 is sandwiched and supported by the punch 16 and the counter punch 18, and is placed on the tip portion 18B of the counter punch 18 in a state where a predetermined pressure (back pressure) is applied. Be placed.

Next, as shown in FIG. 3, the punch 16 and the counter punch 18 are integrally raised toward the product 22 side while supporting the scrap 24 arranged on the tip portion 18B.

The ascending movement of the punch 16 and the counter punch 18 brings the outer edge of the scrap 24 into contact with the end face of the hole in the product 22 supported by the die 12 and the holder 14. Further, by raising the punch 16 and the counter punch 18 integrally, the outer edge of the scrap 24 is pressed against the end face of the hole of the product 22, and the outer edge of the scrap 24 faces the lower side in FIG. It bends and deforms. Further, when ascending, the outer edge of the scrap 24 first contacts the end face of the product 22 and loads the shearing apparatus 10, so that coining is performed. Bending deformation is plastic deformation. Then, after the bending deformation, the scrap 24 is pulled up above the product 22 by further raising the punch 16 and the counter punch 18 integrally.

Here, when the scrap 24 is pulled upward from the product 22, the outer edge of the scrap 24 may be considered separately as a case where it protrudes to the outside of the base 18A of the counter punch 18 and a case where the scrap 24 is located inside the base 18A. It is possible. The present inventors have obtained the finding that the effect of reducing the load or the effect of reducing the residual stress of the product 22 can be obtained in each case.

Specifically, first, as shown in FIGS. 4 and 6, the protrusion width at which the outer edge of the scrap 24 projects to the outside of the base 18A of the counter punch 18 measured along the width L direction of the clearance 15 is defined as D. Set. As shown in FIGS. 4 and 6, the protrusion width D is a virtual state in which the shape of the tip portion 18B and the shape of the center of the deformed scrap 24 are aligned with each other and are in close contact with each other. Can be set under certain conditions. The setting of the protrusion width D can be obtained by, for example, numerical analysis such as the finite element method.

In other words, when the scrap coining method of the present disclosure is applied to actual shearing, the state in which the scrap is completely in close contact with the tip of the counter punch after coining or when the scrap is pulled upward from the product is not satisfied. Not required. In practice, the scrap may be partially lifted from the tip.

As shown in FIG. 4, when the outer edge of the scrap 24 protrudes to the outside of the base 18A of the counter punch 18, it is defined as the case where the protrusion width D is positive (D> 0). Further, as shown in FIG. 6, when the outer edge of the scrap 24 is located inside the base portion 18A of the counter punch 18, it is defined as the case where the protrusion width D is negative (D <0). Hereinafter, the case where D> 0 and the case where D <0 will be described separately. The case where the protrusion width D is zero (zero) is included in the case where D <0. That is, in the present embodiment, when D = 0, it is considered that the same behavior as in the case of D <0 where the outer edge of the scrap 24 does not contact the product 22 occurs.

(When D> 0)
As shown in FIG. 4, when the outer edge of the scrap 24 protrudes to the outside of the base 18A of the counter punch 18 when the scrap 24 is pulled upward from the product 22, the shape of the tip 18B and the center of the deformed scrap 24 It is in close contact with the shape of. Further, the outer edge of the scrap 24 projects to the outside of the base 18A of the counter punch 18. In FIG. 4, the position A3 of the outer edge of the protruding scrap 24 is exemplified inside the clearance 15. Further, the radius RS of the scrap 24 after the bending deformation in FIG. 4 is shorter than the radius RS of the scrap 24 before the bending deformation in FIG. 1.

Therefore, when the punch 16 and the counter punch 18 are raised after the scrap 24 is bent and deformed, the scrap 24 is raised while the protruding outer edge is maintained in contact with the product 22. Therefore, when D> 0, the coining by the scrap 24 continues even after the bending deformation.

When D> 0, the load reduction effect is obtained by setting the protrusion ratio D / L with respect to the width of the clearance 15 of the protrusion width D within a certain range. In this embodiment, the protrusion ratio D / L is set to less than 0.8 so that the load reduction effect can be enhanced, as will be described later with reference to Examples 1 to 8. Further, in the present embodiment, it is more preferable that the protrusion ratio D / L is set to less than 0.6 from the viewpoint that the load reduction effect can be further enhanced.

(When D <0)
On the other hand, as shown in FIG. 5, after punching, the entire lower surface of the scrap 24 may not be in close contact with the surface of the tip portion 18B at the time when the outer edge of the scrap 24 first contacts the end surface of the product 22 and is bent and deformed. be. In FIG. 5, the position of the outer edge of the protruding scrap 24 and the radius of the scrap 24 are not shown for the sake of clarity. Then, as shown in FIG. 6, the diameter of the scrap 24 becomes smaller than the diameter W of the punched hole due to the deformation due to the coining.

Therefore, when the scrap 24 is pulled upward from the product 22, if the outer edge of the scrap 24 is located inside the base 18A of the counter punch 18, the outer edge of the scrap 24 does not protrude to the outside of the base 18A of the counter punch 18. ..

When D <0, the rigidity of the scrap 24 has a great influence on the effect of reducing the residual stress. Therefore, in the present embodiment, when D <0, the effect of reducing the residual stress is the diameter-thickness ratio W / of the diameter W of the punched hole (diameter W of the scrap 24 before coining) to the thickness T of the workpiece 20. It is obtained by setting T within a certain range. In the present embodiment, the diameter-thickness ratio W / T is set to less than 500 so as to enhance the effect of reducing the residual stress, as described with reference to Examples 9 to 11 which will appear later. .. Further, in the present embodiment, the diameter-thickness ratio W / T is more preferably set to less than 60 from the viewpoint that the effect of reducing the residual stress can be further enhanced.

<Comparison example>
On the other hand, as shown in FIG. 7, in the case of the shearing apparatus 10Z according to the comparative example, the tip portion 18B of the counter punch 18 is not provided with a portion having a diameter reduced from that of the base portion 18A. The upper portion of the counter punch 18 of the comparative example has a cylindrical shape having a base portion 18A and a tip portion 18B having the same diameter as the base portion 18A. Therefore, when the counter punch 18 rises after punching and the outer edge of the scrap 24 and the end face of the product 22 first come into contact with each other, the load generated by the contact becomes larger than in the case of the present embodiment.

Further, the scrap 24 is supported in close contact with each other from above and below by punches 16 and counter punches 18 having the same diameter. Therefore, as shown in FIG. 8, when the punch 16 and the counter punch 18 are raised and the scrap 24 is pulled up to the upper side of the product 22, the bending deformation of the outer edge of the scrap 24 as in the present embodiment is substantially present. Difficult.

<Modification example>
The shearing apparatus 10 according to the present embodiment shown in FIGS. 1 to 6 is a shearing apparatus 10 in which the center of the workpiece 20 is punched to form a hole, and the shearing apparatus 10 is performed. Then, it is not limited to this, and can be applied to other shearing processes. The shearing apparatus 10A according to the modified example illustrated in FIG. 9 is a shearing apparatus capable of performing trim processing for cutting the outer peripheral portion of the workpiece 20. The shearing apparatus 10A according to the modified example can be used, for example, in a process of processing or manufacturing a steel part. In addition, it may be arranged in a hot rolling line of a steel mill or the like. The shearing apparatus 10A can be applied to a crop shear or the like that cuts an end portion of a steel plate as a work material 20 into a straight line or a curved line.

The shearing apparatus 10A according to the modified example includes a die 12, a holder 14, a punch 16, and a counter punch 18, similarly to the shearing apparatus 10 according to the present embodiment. In the case of the shearing apparatus 10A illustrated in FIG. 9, unlike the case of piercing, the end face of the product 22 to be coined exists only on one side (the left side in FIG. 9).

Therefore, the tip portion 18B of the counter punch 18 is provided with a reduced diameter portion only on the portion on the left side of the boundary position B1 in FIG. Although not shown, the reduced diameter portion extends linearly in the direction penetrating the paper surface of FIG. A flat upper surface is formed on the portion of the tip portion 18B on the right side of the boundary position B1 in FIG. The surface of the region between the top surface and the base 18A is tapered.

Further, in FIG. 9, the reference line C is a line perpendicular to the horizontal plate surface of the workpiece 20 passing through the boundary position B1 at the left end of the upper surface where the tip portion 18B of the counter punch 18 and the scrap 24 are in contact with each other. be. In the modified example, the distance RCP of the area of the reduced diameter portion between the contact point (boundary position B1) between the tip portion 18B and the scrap 24 and the outer surface of the base portion 18A is between the reference line C and the outer surface of the base portion 18A. Defined in. Since the other configurations of the shearing apparatus 10A according to the modified example are the same as the members having the same name in the shearing apparatus 10 according to the present embodiment, duplicate description will be omitted.

The scrap coining method using the shearing apparatus 10A according to the modified example is the same as that of the present embodiment. However, in the case of the shearing apparatus 10A capable of performing trimming, a member that hinders the movement of the scrap 24 in the horizontal direction of the scrap 24 is not provided as in the region on the right side of the scrap 24 in FIG. There can be a space that has been scraped. Therefore, unless the scrap 24 is securely sandwiched and supported by the punch 16 and the counter punch 18, the scrap 24 may not be completely held during coining. As a result, at the time of coining, the scrap 24 may move horizontally due to the reaction force from the product 22, and the position of the scrap 24 on the counter punch 18 may shift.

Therefore, in the case of the modified example, the area of the upper surface is set to, for example, the counter punch 18 so that the flat upper surface of the tip portion 18B, which is the region in contact with the scrap 24, has a certain area required for supporting the scrap 24. It is preferable to set it to about half or more of the radius RCP of. However, the area of the upper surface is not limited to this and can be changed as appropriate.

As shown in FIG. 10, in the shearing apparatus 10B capable of performing trim processing, even if the tip portion 18B of the counter punch 18 is configured to have a diameter-reduced portion line-symmetrical with respect to the reference line C. good. That is, the shape of the tip portion 18B in FIG. 10 is the same as the shape of the tip portion 18B in FIG. 1, and curved portions having a diameter reduced from that of the base portion 18A are formed on both sides of the reference line C passing through the apex B. There is. Further, the shape of the tip of the counter punch of the shearing apparatus capable of performing trimming may be tapered or curved, or may have the same cross section as in FIGS. 9 and 10 and may have a stepped shape or the like.

Further, in FIGS. 9 and 10, the case of trim processing for linear cutting has been exemplified, but in the present disclosure, trim processing for curved cutting may be used. Specifically, for example, the curved portion of the cutting line is subdivided into a plurality of straight line portions, and each of the subdivided straight line portions has a counter having a reduced diameter tip portion as in the case of FIGS. 9 and 10. Shearing may be performed so that the coining using the punch is performed.

Next, the relationship between the protrusion ratio D / L and the maximum load applied to the shearing apparatus 10 will be described with reference to Examples 1 to 8 below.

(Example 1)
In Example 1, a 980 MPa class steel sheet is prepared as the work material 20, and piercing is performed using a shearing apparatus 10 provided with a counter punch 18 having a spherical tip portion 18B in FIG. 2 (A). bottom. Further, the thickness T of the steel plate was set to 0.5 mm, the clearance ratio was set to 10% of the thickness T, and the width L of the clearance 15 was set to 0.05 mm. Further, the diameter W of the punched hole was set to 30 mm. The diameter-thickness ratio W / T was 60. Further, the radius RCP of the counter punch 18 was set to 15 mm. Then, by changing the height H of the tip portion 18B, the radius RS of the scrap 24 after coining was changed to a plurality of patterns.

Then, the protrusion width D, the protrusion ratio D / L, the maximum load P during coining, and the reduction amount ΔP of the maximum load P were measured in each case of the different radii RS. Further, on the end face of the product 22 after coining, the residual stress in the plate thickness direction (vertical direction in FIG. 1) and the residual stress in the plate width direction (horizontal direction in FIG. 1) were measured, respectively. For the measurement of the residual stress, a known method such as an X-ray method or a drilling method can be adopted. In the present embodiment, the residual stress is measured by irradiating the center of each of the plate thickness direction and the plate width direction on the end face with X-rays having a beam diameter of 500 μm. The residual stress may be measured together with the load by analysis using simulation software or the like.

Further, piercing was performed using the shearing apparatus 10Z according to the comparative example, which was provided with a counter punch 18 having no reduced diameter portion and having the same shape as the base portion at the tip portion. Other conditions in the comparative example are the same as in the case of the first embodiment. Then, the difference between the maximum load P of Example 1 and the maximum load P of the comparative example was calculated as the reduction amount ΔP of the maximum load P.

Further, in the shearing apparatus 10Z according to the comparative example, the residual stress of the product 22 obtained when the shearing was completed by performing only punching without performing coining was measured as a reference reference value. In the shearing process in which only punching is performed, the processing conditions other than the coining are the same as in the case of the first embodiment. Then, the difference between the residual stress of Example 1 and the residual stress of the reference reference value was calculated as the reduction amount Δσ of the residual stress. The measurement results are shown in Table 1 and FIG. 11 below.

In FIGS. 11 to 18 below, in the protrusion ratio D / L on the horizontal axis, D / L = 1 corresponds to a comparative example. Further, as the value of D / L becomes smaller, the value of the height H of the tip portion in each embodiment becomes larger. If the residual stress σ value shown in the table is positive, it means that the residual stress is tensile residual stress, and if the residual stress σ value is negative, it means that the residual stress is compressive residual stress. means. In the present embodiment, it is preferable that the residual stress tends toward compression, that is, the value of the residual stress σ becomes small, from the viewpoint of ensuring the quality of the product 22.

As shown in FIG. 11A, in Example 1, it can be seen that the smaller the protrusion ratio D / L, the smaller the maximum load P. Further, as shown in FIG. 11B, it can be seen that the effect of reducing the residual stress is also obtained in Example 1. For example, when the protrusion ratio D / L is 0.4 mm, the reduction amount Δσ of the residual stress in the plate thickness direction is 552.29 MPa or more, and the reduction amount Δσ of the residual stress in the plate width direction is 1000. 37 MPa or more is obtained. The effect of reducing the residual stress of Example 1 is comparable to that of the comparative example, and is effective in actual shearing.

(Example 2)
In Example 2, a 980 MPa class steel sheet is prepared as the work material 20, and piercing is performed using a shearing apparatus 10 provided with a counter punch 18 having a spherical tip portion 18B in FIG. 2 (A). bottom. Further, the thickness T of the steel plate was set to 1.6 mm, the clearance ratio was set to 10% of the thickness T, and the width L of the clearance 15 was set to 0.16 mm. Further, the diameter W of the punched hole was set to 30 mm. The diameter-thickness ratio W / T was 18.75. Further, the radius RCP of the counter punch 18 was set to 10 mm. Then, by changing the height H of the tip portion 18B, the radius RS of the scrap 24 after coining was changed.

Then, the protrusion width D, the protrusion ratio D / L, the maximum load P during coining, and the reduction amount ΔP of the maximum load P were measured in each case. Further, the residual stress of the end face of the product 22 after coining was measured in each of the plate thickness direction and the plate width direction. Other measurement conditions are the same as in the case of Example 1. The measurement results are shown in Table 2 and FIG. 12 below.

As shown in FIG. 12A, it can be seen that in the second embodiment as well, the smaller the protrusion ratio D / L is, the smaller the maximum load P is. Further, as shown in FIG. 12B, it can be seen that the effect of reducing the residual stress is also obtained in Example 2. For example, when the protrusion ratio D / L is 0.3 mm, the reduction amount Δσ of the residual stress in the plate thickness direction is 538.13 MPa or more, and the reduction amount Δσ of the residual stress in the plate width direction is 980. 31 MPa or more is obtained. The effect of reducing the residual stress of Example 2 is effective in actual shearing as in the case of Example 1.

(Example 3)
In Example 3, a 980 MPa class steel sheet is prepared as the work material 20, and piercing is performed using a shearing apparatus 10 provided with a counter punch 18 having a spherical tip portion 18B in FIG. 2 (A). bottom. Further, the thickness T of the steel plate was set to 1.6 mm, the clearance ratio was set to 10% of the thickness T, and the width L of the clearance 15 was set to 0.16 mm. Further, the diameter W of the punched hole was set to 30 mm. The diameter-thickness ratio W / T was 18.75. Further, the radius RCP of the counter punch 18 was set to 15 mm. Then, by changing the height H of the tip portion 18B, the radius RS of the scrap 24 after coining was changed.

Then, the protrusion width D, the protrusion ratio D / L, the maximum load P during coining, and the reduction amount ΔP of the maximum load P were measured in each case. Further, the residual stress of the end face of the product 22 after coining was measured in each of the plate thickness direction and the plate width direction. Other measurement conditions are the same as in the case of Example 1. Example 3 differs from Example 2 only in the value of the radius RCP of the counter punch 18. The measurement results are shown in Table 3 and FIG. 13 below.

As shown in FIG. 13A, it can be seen that in the third embodiment as well, the smaller the protrusion ratio D / L is, the smaller the maximum load P is. Further, as shown in FIG. 13B, it can be seen that the effect of reducing the residual stress is also obtained in Example 3. For example, when the protrusion ratio D / L is 0.3 mm, the reduction amount Δσ of the residual stress in the plate thickness direction is 540.74 MPa or more, and the reduction amount Δσ of the residual stress in the plate width direction is 980. It is obtained at 09 MPa or more. The effect of reducing the residual stress in Example 3 is effective in actual shearing, as in the cases of Examples 1 and 2.

(Example 4)
In Example 4, a 980 MPa class steel sheet is prepared as the work material 20, and piercing is performed using a shearing apparatus 10 provided with a counter punch 18 having a spherical tip portion 18B in FIG. 2 (A). bottom. Further, the thickness T of the steel plate was set to 4 mm, the clearance ratio was set to 10% of the thickness T, and the width L of the clearance 15 was set to 0.4 mm. Further, the diameter W of the punched hole was set to 30 mm. The diameter-thickness ratio W / T was 7.5. Further, the radius RCP of the counter punch 18 was set to 15 mm. Then, by changing the height H of the tip portion 18B, the radius RS of the scrap 24 after coining was changed.

Then, the protrusion width D, the protrusion ratio D / L, the maximum load P during coining, and the reduction amount ΔP of the maximum load P were measured in each case. Further, the residual stress of the end face of the product 22 after coining was measured in each of the plate thickness direction and the plate width direction. Other measurement conditions are the same as in the case of Example 1. The measurement results are shown in Table 4 and FIG. 14 below.

As shown in FIG. 14A, it can be seen that in the fourth embodiment as well, the smaller the protrusion ratio D / L is, the smaller the maximum load P is. Further, as shown in FIG. 14B, it can be seen that the effect of reducing the residual stress is also obtained in Example 4. For example, when the protrusion ratio D / L is 0.1 mm, the reduction amount Δσ of the residual stress in the plate thickness direction is 489.29 MPa or more, and the reduction amount Δσ of the residual stress in the plate width direction is 977. 37 MPa or more is obtained. The effect of reducing the residual stress in Example 4 is effective in actual shearing, as in the cases of Examples 1 to 3.

(Example 5)
In Example 5, a 980 MPa class steel plate is prepared as the work material 20, and a shearing apparatus 10 provided with a counter punch 18 having a spherical tip portion 18B having a flat upper surface in FIG. 2B is used. Piercing was performed. Further, the thickness T of the steel plate was set to 1.6 mm, the clearance ratio was set to 10% of the thickness T, and the width L of the clearance 15 was set to 0.16 mm. Further, the diameter W of the punched hole was set to 30 mm. The diameter-thickness ratio W / T was 18.75. Further, the radius RCP of the counter punch 18 was set to 15 mm. Then, by changing the height H of the tip portion 18B, the radius RS of the scrap 24 after coining was changed.

Then, the protrusion width D, the protrusion ratio D / L, the maximum load P during coining, and the reduction amount ΔP of the maximum load P were measured in each case. Further, the residual stress of the end face of the product 22 after coining was measured in each of the plate thickness direction and the plate width direction. Other measurement conditions are the same as in the case of Example 1. The measurement results are shown in Table 5 and FIG. 15 below.

As shown in FIG. 15A, it can be seen that in the fifth embodiment as well, the smaller the protrusion ratio D / L is, the smaller the maximum load P is. Further, as shown in FIG. 15B, it can be seen that the effect of reducing the residual stress is also obtained in Example 5. For example, when the protrusion ratio D / L is 0.3 mm, the reduction amount Δσ of the residual stress in the plate thickness direction is 563.59 MPa or more, and the reduction amount Δσ of the residual stress in the plate width direction is 982. 28 MPa or more is obtained. The effect of reducing the residual stress in Example 5 is effective in actual shearing, as in the cases of Examples 1 to 4.

(Example 6)
In Example 6, a 980 MPa class steel plate was prepared as the work material 20, and piercing was performed using a shearing apparatus 10 provided with a counter punch 18 having a conical tip portion 18B in FIG. 2C. .. Further, the thickness T of the steel plate was set to 1.6 mm, the clearance ratio was set to 10% of the thickness T, and the width L of the clearance 15 was set to 0.16 mm. Further, the diameter W of the punched hole was set to 30 mm. The diameter-thickness ratio W / T was 18.75. Further, the radius RCP of the counter punch 18 was set to 15 mm. Then, by changing the height H of the tip portion 18B, the radius RS of the scrap 24 after coining was changed.

Then, the protrusion width D, the protrusion ratio D / L, the maximum load P during coining, and the reduction amount ΔP of the maximum load P were measured in each case. Further, the residual stress of the end face of the product 22 after coining was measured in each of the plate thickness direction and the plate width direction. Other measurement conditions are the same as in the case of Example 1. The measurement results are shown in Table 6 and FIG. 16 below.

As shown in FIG. 16A, it can be seen that in the sixth embodiment as well, the smaller the protrusion ratio D / L is, the smaller the maximum load P is. Further, as shown in FIG. 16B, it can be seen that the effect of reducing the residual stress is also obtained in Example 6. For example, when the protrusion ratio D / L is 0.3 mm, the reduction amount Δσ of the residual stress in the plate thickness direction is 563.59 MPa or more, and the reduction amount Δσ of the residual stress in the plate width direction is 993. 28 MPa or more is obtained. The effect of reducing the residual stress in Example 6 is effective in actual shearing, as in the cases of Examples 1 to 5.

(Example 7)
In Example 7, a 980 MPa class steel sheet was prepared as the work material 20, and trimming was performed using a shearing apparatus 10 equipped with a counter punch 18 having a tapered tip portion 18B in FIG. Further, the thickness T of the steel plate was set to 1.6 mm, the clearance ratio was set to 10% of the thickness T, and the width L of the clearance 15 was set to 0.16 mm. Further, the diameter W of the punched hole was set to 30 mm. The diameter-thickness ratio W / T was 18.75. Further, the radius RCP of the counter punch 18 was set to 15 mm. Then, by changing the height H of the tip portion 18B, the radius RS of the scrap 24 after coining was changed.

Then, the protrusion width D, the protrusion ratio D / L, the maximum load P during coining, and the reduction amount ΔP of the maximum load P were measured in each case. Further, the residual stress of the end face of the product 22 after coining was measured in each of the plate thickness direction and the plate width direction. Other measurement conditions are the same as in the case of Example 1. The measurement results are shown in Table 7 and FIG. 17 below.

As shown in FIG. 17A, it can be seen that in the seventh embodiment as well, the smaller the protrusion ratio D / L, the smaller the maximum load P. Further, as shown in FIG. 17B, it can be seen that the effect of reducing the residual stress is also obtained in Example 7. For example, when the protrusion ratio D / L is 0.3 mm, the reduction amount Δσ of the residual stress in the plate thickness direction is 520.59 MPa or more, and the reduction amount Δσ of the residual stress in the plate width direction is 1016. 28 MPa or more is obtained. The effect of reducing the residual stress in Example 7 is effective in actual shearing, as in the cases of Examples 1 to 6.

(Example 8)
In Example 8, a 300 MPa class aluminum plate is prepared as the work material 20, and piercing is performed using a shearing apparatus 10 provided with a counter punch 18 having a spherical tip portion 18B in FIG. 2 (A). carried out. Further, the thickness T of the steel plate was set to 1.6 mm, the clearance ratio was set to 10% of the thickness T, and the width L of the clearance 15 was set to 0.16 mm. Further, the diameter W of the punched hole was set to 30 mm. The diameter-thickness ratio W / T was 18.75. Further, the radius RCP of the counter punch 18 was set to 15 mm. Then, by changing the height H of the tip portion 18B, the radius RS of the scrap 24 after coining was changed.

Then, the protrusion width D, the protrusion ratio D / L, the maximum load P during coining, and the reduction amount ΔP of the maximum load P were measured in each case. Further, the residual stress of the end face of the product 22 after coining was measured in each of the plate thickness direction and the plate width direction. Other measurement conditions are the same as in the case of Example 1. The measurement results are shown in Table 8 and FIG. 18 below.

As shown in FIG. 18A, it can be seen that in the eighth embodiment as well, the smaller the protrusion ratio D / L is, the smaller the maximum load P is. Further, as shown in FIG. 18B, it can be seen that the effect of reducing the residual stress is also obtained in Example 8. For example, when the protrusion ratio D / L is 0.3 mm, the reduction amount Δσ of the residual stress in the plate thickness direction is 210.24 MPa or more, and the reduction amount Δσ of the residual stress in the plate width direction is 405. 11 MPa or more is obtained. The effect of reducing the residual stress of Example 8 is effective in actual shearing, as in the case of Examples 1 to 7. Further, it can be seen that the present disclosure can be applied even when the workpiece 20 is a metal material other than the high-strength steel plate, as in the aluminum plate of Example 8.

In this embodiment, as in Examples 1 to 8, it can be seen that the smaller the protrusion ratio D / L, the more the maximum load generated in the shearing apparatus 10 can be reduced. In particular, when the protrusion ratio D / L is less than 0.8, it can be seen that the load reduction effect is enhanced. Further, it can be seen that the load reduction effect is further enhanced by setting the protrusion ratio D / L to less than 0.6. It can also be seen that the residual stress on the end face of the product 22 is also reduced.

However, as shown in FIGS. 11 to 18, when the protrusion ratio D / L is negative, that is, when D <0, the influence of the protrusion ratio D / L on the load reduction effect is compared. It becomes smaller. Then, in order to control the reduction amount Δσ of the residual stress, the diameter-thickness ratio W / T is adjusted. Next, the relationship between the diameter-thickness ratio W / T and the residual stress reduction amount Δσ will be described with reference to Examples 9 to 11 below, especially when D <0. Although description is omitted, it goes without saying that the load reduction effect is also obtained in Examples 9 to 11.

(Example 9)
In Example 9, a 980 MPa class steel sheet is prepared as the work material 20, and piercing is performed using a shearing apparatus 10 provided with a counter punch 18 having a spherical tip portion 18B in FIG. 2 (A). bottom. The clearance ratio was 10% of the thickness T of the steel sheet. Further, the thickness T of the workpiece 20 was set to 2 mm and the diameter W of the punched hole was set to 30 mm so that the diameter-thickness ratio W / T = 15. Further, the radius RCP of the counter punch 18 was set to 15 mm. Then, on the end face of the product 22 after coining, the residual stress in the plate thickness direction and the residual stress in the plate width direction were measured, respectively.

Further, piercing was performed using the shearing apparatus 10Z according to the comparative example, which was provided with a counter punch 18 having no reduced diameter portion and having the same shape as the base portion at the tip portion. Further, in the comparative example, the shearing process was completed with punching without performing coining. Other conditions in the comparative example are the same as in the case of the ninth embodiment. Then, the difference between the residual stress of Example 9 and the residual stress of Comparative Example was calculated as the reduction amount Δσ of the residual stress.

The measurement results are shown in Table 9 below. The amount of reduction in residual stress Δσ in the plate thickness direction of Example 9 is represented by the data points marked with white circles (◯) on the leftmost side in FIG. Further, the reduction amount Δσ of the residual stress in the plate width direction of Example 9 is represented by the data points marked with black circles (●) on the leftmost side in FIG.

(Example 10)
In Example 10, the thickness T of the workpiece 20 was set to 1 mm and the diameter W of the punched hole was set to 60 mm so that the diameter-thickness ratio W / T = 60. Further, the radius RCP of the counter punch 18 was set to 30 mm. Other conditions are the same as in the case of Example 9. Then, the residual stress of the end face of the product 22 after coining was measured in each of the plate thickness direction and the plate width direction.

The measurement results are shown in Table 10 below. The amount of reduction in residual stress Δσ in the plate thickness direction of Example 10 is represented by the data point marked with a circle from the left in FIG. Further, the reduction amount Δσ of the residual stress in the plate width direction of Example 10 is represented by the data point marked with ●, which is the second from the left side in FIG.

(Example 11)
In Example 11, the thickness T of the workpiece 20 was set to 0.5 mm and the diameter W of the punched hole was set to 250 mm so that the diameter-thickness ratio W / T = 500. Further, the radius RCP of the counter punch 18 was set to 125 mm. Other conditions are the same as in the case of Example 9. Then, the residual stress of the end face of the product 22 after coining was measured in each of the plate thickness direction and the plate width direction.

The measurement results are shown in Table 11 below. The amount of reduction in residual stress Δσ in the plate thickness direction of Example 11 is represented by the data points marked with ◯ on the far right in FIG. Further, the reduction amount Δσ of the residual stress in the plate width direction of Example 11 is represented by the data points marked with ● on the far right side of FIG. 19 and partially overlapping the data points marked with ○.

As shown in Examples 9 to 11, in the present embodiment, when D <0, it can be seen that the smaller the diameter-thickness ratio W / T, the larger the amount of reduction in the obtained residual stress Δσ. In particular, it can be seen that the effect of reducing the residual stress is enhanced when the diameter-thickness ratio W / T is less than 500. Further, it can be seen that the effect of reducing the residual stress is further enhanced when the diameter-thickness ratio W / T is less than 60.

(Action effect)
In the present embodiment, when the counter punch 18 is moved toward the product 22 side after shearing, the outer edge of the scrap 24 is bent and deformed when the scrap 24 is coined in contact with the end face of the product 22. Since the load generated between the product 22 and the scrap 24 during coining is absorbed by the bending deformation, the load on the shearing device 10 side that receives the load is reduced. Therefore, there is no need to increase the capacity of the impact mitigation device such as a gas cushion.

Further, in the present embodiment, the counter punch 18 has a tip portion 18B having a diameter reduced from that of the base portion 18A, and the scrap 24 is arranged on the upper side of the tip portion 18B. Therefore, as compared with the case of coining in which the tip portion 18B has the same diameter as the base portion 18A and the counter punch 18 having a flat upper surface of the tip portion 18B is used, scrap is performed along the shape of the reduced diameter tip portion 18B during coining. The outer edge of the 24 can be smoothly bent and deformed.

Further, in the present embodiment, since the tip portion 18B is gradually reduced in diameter from the base portion 18A toward the work piece 20 side, the outer edge of the scrap 24 can be bent and deformed more smoothly. Therefore, the burden on the shearing apparatus 10 side can be further reduced.

Further, in the present embodiment, as shown in FIGS. 2 (B), 2 (D), 2 (E) and 2 (F), when the tip portion 18B has a flat upper surface, the flat upper surface is formed. As a result, the area in which the counter punch 18 comes into contact with the punch 16 increases, so that the scrap 24 can be supported more stably while the counter punch 18 is moving.

Further, in the present embodiment, as shown in FIG. 2C, when the tip portion 18B has a cone shape, the entire tip portion 18B is sharpened toward the upper side, so that the tip portion 18B is bent and deformed during coining. There is almost no unusable area, and bending can be performed reliably.

Further, in the present embodiment, a shearing machine 10 capable of performing piercing is realized. Therefore, the effect of reducing the coining load can be enhanced in the piercing process.

Further, in the present embodiment, after the outer edge of the scrap 24 is bent and deformed, the state in which the scrap 24 and the product 22 are in contact with each other may be maintained. Even after bending deformation, the coining is continued while the protruding outer edge of the scrap 24 is maintained in contact with the product 22, so that the coining time becomes longer, so that the effect of reducing the residual stress due to the coining can be enhanced. ..

Further, in the present embodiment, when the contact state between the outer edge of the scrap 24 and the product 22 is maintained after bending and deformation, the protrusion ratio D / L is set to less than 0.8, thereby reducing the load. Can be enhanced.

Further, in the present embodiment, when the contact state between the outer edge of the scrap 24 and the product 22 is maintained after bending and deformation, the protrusion ratio D / L is set to less than 0.6, thereby reducing the load. Can be further enhanced.

Further, in the present embodiment, after the outer edge of the scrap 24 is bent and deformed to perform coining, the outer edge of the scrap 24 is located inside the base 18A of the counter punch 18, and the outer edge of the scrap 24 comes into contact with the product 22. The condition may be avoided. After the bending deformation, the counter punch 18 moves while the outer edge of the scrap 24 and the product 22 are not in contact with each other, so that no further load is applied to the shearing apparatus 10.

Further, in the present embodiment, when the contact state between the outer edge of the scrap 24 and the product 22 is avoided after bending and deformation, the diameter-thickness ratio W / T is less than 500, so that the effect of reducing the residual stress is enhanced. be able to.

Further, in the present embodiment, when the contact state between the outer edge of the scrap 24 and the product 22 is avoided after bending and deformation, the diameter-thickness ratio W / T is less than 60, so that the effect of reducing the residual stress is further enhanced. Can be enhanced.

Further, in the present embodiment, since the workpiece 20 is a metal material, the effect of reducing the coining load at the time of coining using the metal material can be enhanced.

Further, also in the modified examples shown in FIGS. 9 and 10, when the counter punch 18 is moved toward the product 22 side after shearing as in the case of the present embodiment, the scrap 24 comes into contact with the end face of the product 22. At the time of shearing, the outer edge of the scrap 24 is bent and deformed. Since the load generated between the product 22 and the scrap 24 during coining is absorbed by the bending deformation, the load on the shearing device 10 side that receives the load is reduced. Therefore, there is no need to increase the capacity of the impact mitigation device such as a gas cushion.

Further, in the modified example, a shearing machine 10 capable of performing trimming is realized. Therefore, in the trim processing, the effect of reducing the coining load can be enhanced. Other effects of the shearing apparatus 10 according to the modified example are the same as in the case of the present embodiment.

<Other embodiments>
Although the present disclosure has been described by the embodiments disclosed above, this description is not limiting the present disclosure. It should be considered from this disclosure to those skilled in the art that various alternative embodiments, examples and operational techniques will be apparent.

For example, the present disclosure can be configured by partially combining the structures of the shearing apparatus shown in FIGS. 1 to 19. The present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the matters specifying the invention within the scope of claims reasonable from the above description.

10 Shearing equipment 12 Die 14 Holder 15 Clearance 16 Punch 18 Counter punch 18A Base 18B Tip 20 Work material 22 Product 24 Scrap A1 Die inner side position A2 Counter punch outer side position A3 Scrap outer edge position B Vertex B1 Boundary position C Reference line (central axis)
D Overhang width H Height L Clearance width RCP Counter punch radius (distance of reduced diameter area)
RS Scrap radius T Thickness W Punched hole diameter (scrap diameter before bending and deformation)

Claims (15)

With the die
A holder that sandwiches the work material with the die,
A punch placed with a clearance between the die and the punch,
A counter punch placed facing the punch and
Using a shearing machine equipped with
The work material is sheared by the die and the punch to form a product, the product is supported between the die and the holder, and the portion separated from the work material by the shearing is scrapped. Placed on the tip of the counter punch as
With the scrap placed on the upper side, the counter punch is moved toward the product side, and the outer edge of the scrap is brought into contact with the end face of the supported product to bend and deform the outer edge of the scrap while coining. do,
Scrap coining method. The counter punch has a base portion and a tip portion provided on the workpiece side of the base portion and having a diameter reduced from the base portion.
The scrap coining method according to claim 1. The reduced diameter portion of the tip portion is gradually reduced in diameter from the base side to the workpiece side.
The scrap coining method according to claim 2. The tip has a flat top surface and a reduced diameter region between the top surface and the base.
The scrap coining method according to claim 2 or 3. The tip is pointed upwards,
The scrap coining method according to claim 2 or 3. The shearing is piercing.
The scrap coining method according to any one of claims 1 to 5. The shearing is a trimming process.
The scrap coining method according to any one of claims 1 to 4. After the outer edge of the scrap is bent and deformed,
Match the shape of the tip with the shape of the center of the scrap in contact with the tip.
The outer edge of the scrap protrudes to the outside of the base of the counter punch, and the counter punch is moved while maintaining the state in which the outer edge is in contact with the product to continue coining after the bending deformation.
The scrap coining method according to any one of claims 1 to 7. Let L be the width of the clearance.
When D is the protrusion width at which the outer edge of the scrap protrudes to the outside of the base of the counter punch measured along the width direction of the clearance.
The protrusion ratio D / L of the protrusion width to the width of the clearance is less than 0.8.
The scrap coining method according to claim 8. The protrusion ratio D / L is less than 0.6.
The scrap coining method according to claim 9. After the outer edge of the scrap is bent and deformed,
The outer edge of the scrap is located inside the base of the counter punch, and the counter punch is moved while maintaining the state in which the outer edge is not in contact with the product.
The scrap coining method according to any one of claims 1 to 7. Let W be the diameter of the scrap before coining.
When the thickness of the work material is T,
The diameter-thickness ratio W / T of the diameter of the scrap to the thickness of the work piece is less than 500.
The scrap coining method according to claim 11. The diameter-thickness ratio W / T is less than 60.
The scrap coining method according to claim 12. The work material is a metal material.
The scrap coining method according to any one of claims 1 to 13. With the die
A holder that sandwiches the work material with the die,
A punch placed with a clearance between the die and the punch,
A counter punch which is arranged to face the punch and has a base portion and a tip portion provided on the workpiece side of the base portion and having a diameter reduced from the base portion.
Shearing equipment equipped with.

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