JPH08300299A - Working member and manufacture thereof - Google Patents

Abstract

PURPOSE: To reduce a tensile stress working in a moment whenever a workpiece is stamped out, checking an extent of fatigue, and to prevent the separation and falling-off of a wear resistant film from occurring by forming a film being harder than a base material on the sidepiece inclusive of a cutting edge pf a base substance, and installing a cavitied part on a cutting edge end face to be faced to the workpiece of the base substance. CONSTITUTION: A film 3 being harder than a base material 1 is formed on the surface of a edge side face 2 of a punch consisting of this base material 1. An edge end face 4 of the punch is made up of a horizontal surface 6 in an area between a part separated as long as a distance of a. 2 to 2 times over the thickness of a workpiece from a cutting edge 5 and this edge 5, and a cavitied part 7 of an area excepting this horizontal surface in the edge end face 4. This cavitied part 7 is installed in the edge end face to be faced to the workpiece of the base material 1, whereby an extent of mass in a part where both compression and tensile stresses are work, so that it works so as to reduce the tensile stress to be produced in and around the cutting edge 5 of the punch in a moment whenever the workpiece is stamped out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing member and a method for manufacturing the same, and more particularly to a die part such as a punch and a die used for punching a material to be processed.

[0002]

2. Description of the Related Art FIG. 5 is described in Reference-2 New Pressing Handbook (Nikkan Kogyo Shimbun, 1993) p2.
It is a schematic sectional drawing which showed the punch and die for conventional punching. With reference to FIG. 5, the punch 101 has a cutting edge side surface 102, a cutting edge end surface 103, and a cutting edge 104. Further, the cutting edge side surface 1 of the die 105 is located at a position spaced apart from the cutting edge side surface 102 of the punch 101 by a predetermined distance.
The die 105 is installed so that 06 is located. On the cutting edge face 107 of the die 105, the work material 108 is
Is placed.

As a base material for the punch 101 and the die 105, a steel material or a cemented carbide having a hardness and toughness as large as possible is generally used in consideration of durability when used in punching and workability into a desired shape. To be Punch 101
As a manufacturing method of, the cutting edge side surface 102 and the cutting edge end surface 103 having a desired shape are formed by mechanical processing such as cutting or grinding, or electric power processing. As a result, the cutting edge 104 is also formed. Incidentally, in the conventional punch 101 and die 105, a wear-resistant coating may be formed on the surface of the punch 101 and the die 105 in order to prolong the service life.

FIG. 6 is a drawing showing the shape of a conventional round punch for a press die described in JIS-B-5009. As shown in FIG. 6, conventionally, the cutting edge end face 103 of the punch 101 and the cutting edge end face 107 of the die 105 in FIG.
Are the cutting edge side surface 102 and the cutting edge side surface 106, respectively.
It was composed of a plane orthogonal to.

FIG. 7 is a sectional view showing a conventional coating punch for punching. The wear resistant coating 109 was formed on the cutting edge end surface 103 and the cutting edge side surface 102 which are formed by a plane orthogonal to the cutting edge side surface 102.

[0006]

First, when the material 108 to be processed is punched using the conventional punch 101 for punching and the die 105 shown in FIG. 5, it occurs in the vicinity of the cutting edge 104 of the punch 101. The internal stress to be applied will be described. FIG. 8 is a graph showing changes in internal stress generated near the cutting edge 104 of the punch 101.

After the punching process is started, the punch 101 descends and the cutting edge face 103 of the punch 101 is formed on the surface of the material 108 to be processed placed on the cutting edge face 107 of the die 105.
At the moment of collision, the cutting edge 1 inside the punch 101
A large compressive stress is generated near 04. After that, the impact force of the collision is relieved and the compressive stress is temporarily reduced, but as the punch 101 is pushed into the work material 108, the compressive stress inside the punch 101 gradually increases due to the shear resistance of the work material 108. As the punch 101 is further pushed, a crack is generated in the material to be processed 108, and as the processing further progresses and the shearing surface of the material to be processed 108 in the plate thickness direction increases, the shear resistance of the material to be processed 108 decreases. Then, the compressive stress inside the punch 101 gradually decreases. Finally, the material 108 to be processed is broken.

The compressive force applied to the punch 101 is instantly removed at the moment of this breakage, but at this time, the elasticity stored in the constant volume from the end surface 103 of the cutting edge of the punch 101 as internal energy by the compressive stress. The strain is rapidly released, and the cutting edge face 103, which is the free end, is displaced in the pushing direction with a large acceleration. At the next moment, in the process of absorbing the impact displacement energy by the elasticity of the punch 101, a large tensile stress acts inside the punch 101. It is known that the magnitude of the tensile stress generated inside the punch 101 at the moment of this fracture sometimes reaches a value comparable to the magnitude of the compressive stress generated in the preceding stage,
It goes without saying that the state of this stress change also applies to the die 105.

As described above, the conventional punch 1 for punching is used.
01 and the vicinity of the cutting edge of the die 105, compressive stress and tensile stress are repeatedly generated at each punching process.

FIG. 9 shows a yield stress of 24 Kgf / mm ² , using a conventional punching punch having a diameter of 1.5 mm, which is described in a new press working handbook (Nikkan Kogyo Shimbun, 1993) p3. It is the surface pressure distribution in the vicinity of the cutting edge of the punch when punching a 1 mm thick thin plate. The horizontal axis of FIG. 9A is the cutting edge 104 of FIG.
Represents the distance along the cutting edge face 103, with
The horizontal axis of FIG. 9B represents the distance along the cutting edge side surface 102 with the cutting edge 104 of FIG. 5 as the origin.

From this graph, it can be seen that the largest pressure acts on the edge portion of the cutting edge. Even if it is judged in consideration of this and that the tensile stress generated inside the punch at the moment of breaking the material to be processed is due to the mass of the portion existing on the end face side of the cutting edge of the punch itself, The position where the values of the compressive stress and the tensile stress repeatedly generated for each time become maximum is a portion on the side surface of the cutting edge, which is slightly apart from the cutting edge.

Therefore, in the conventional punching punch and die shown in FIGS. 5 and 6, the portion on the side of the cutting edge, which is slightly apart from the edge of the cutting edge, is repeatedly compressed at each punching operation. The material fatigue progresses due to the stress and tensile stress, and linear cracks and dropout of the material particles occur at the location.

Further, in the conventional coating punch and die for punching shown in FIG. 7, due to the occurrence of linear cracks and dropping of material particles due to the above-mentioned material fatigue, the resistance to corrosion formed on the side surface of the cutting edge is increased. There is a problem that the abradable coating film peels off and falls off, and as a result, the effect of improving the life of the coating film is insufficient.

Further, the occurrence of linear cracks and falling of material particles due to material fatigue can be suppressed by using a mold material having excellent fatigue strength, but since they are brittle materials, they are not used during use. Chipping is likely to occur. That is, a high hardness material for ensuring fatigue strength and wear resistance and a high toughness material for ensuring fracture resistance are contradictory, and a punch and a die satisfying both of them cannot be realized. For this reason, conventionally, both base material fatigue and chipping, which lead to peeling or falling of the coating film on the surface, are prevented,
There is a problem that it is difficult to manufacture a punch and a die that can make full use of the abrasion resistance of the coating film.

The present invention has been made to solve the above problems, and in the processing member, it is formed on the surface of the base material while suppressing the generation of cracks on the side surface of the cutting edge of the base material. The purpose is to extend the life by preventing the abrasion-resistant coating from peeling off. Another object of the present invention is to manufacture a processing member having a long life stably and with high productivity in a method for manufacturing a processing member.

[0016]

According to a first aspect of the present invention, a base body, a coating film formed on a side surface of the base body including a cutting edge and harder than the base material, and a depression edge surface facing a workpiece are depressed. It is a processed member provided with a part.

According to a second aspect of the present invention, the distance from the cutting edge of the first aspect to the depression is 1.2 to 2 times the thickness of the workpiece.

According to a third aspect of the present invention, a substrate, a coating film formed on a side surface including a cutting edge of the substrate and harder than the substrate, and a cutting edge end surface of the substrate facing the workpiece are the surface of the workpiece. And a at least one second surface inclined with respect to the first surface.

According to a fourth aspect of the present invention, in the third aspect, the angles at which a plurality of surfaces constituting the cutting edge face are adjacent to each other are 170 degrees or more and less than 180 degrees.

According to a fifth aspect of the present invention, a layer harder than other portions is formed at a predetermined depth on a side surface of the base which is separated from the cutting edge by a predetermined distance or more, and a coating harder than the base is formed on the side surface of the base. is there.

According to a sixth aspect of the present invention, in the fifth aspect, a layer harder than other portions is provided on the side surface of the base body separated by 0.05 mm or more from the cutting edge.

According to a seventh aspect of the present invention, there is provided a first step of forming a layer harder than other portions at a predetermined depth on a side surface of the base, which is separated from the cutting edge by a predetermined distance or more, and the cutting of the base. And a second step of forming a coating film harder than the base body on the side surface including the blade edge.

According to an eighth aspect of the present invention, in the second aspect of the present invention, at least one of a martensite phase, a nitride, a boride, a carbon compound, a titanium compound and a tungsten compound is used in the second step by local heating or ion irradiation. It is a manufacturing method of the member for processing of Claim 7 which forms.

[0024]

According to the present invention, since the mass of the portion where the compressive stress and the tensile stress act is reduced by providing the recessed portion on the end face of the cutting edge of the substrate which faces the work piece, the work material is punched at the moment. It works to reduce the tensile stress generated near the cutting edge of the punch. This is because the tensile stress is proportional to the mass of the compressed portion. Since the tensile stress can be reduced, fatigue can be suppressed, and the abrasion resistant coating formed on the side surface of the cutting edge can be prevented from peeling off or falling off. This makes it possible to maximize the effect of improving the life of the coating film, and to obtain a die component for punching having a long life.

According to the present invention, the end face of the cutting edge facing the workpiece is constituted by the first surface parallel to the surface of the workpiece and the second surface inclined with respect to the first surface. The punching of the work piece is sequentially performed by punching by the second surface after punching by the first surface. First, the first surface collides with the work piece and is compressed. However, since the first surface has a smaller area than the entire end face of the cutting edge facing the work piece, the volume of the portion that receives the compression force is small, and therefore, The tensile stress generated at the moment of punching the first surface is reduced. Next, the second surface collides with the work piece and is compressed. However, since the second surface has a smaller area than the entire cutting edge face, the volume of the portion that receives the compressive force is small, and thus the second surface is compressed. The tensile stress generated at the moment of punching the surface can be reduced. As described above, since the generation of the tensile stress is dispersed over time, it is possible to suppress the fatigue of the punch base metal and prevent the abrasion resistant coating formed on the side surface of the cutting edge from peeling off or falling off. This makes it possible to obtain a die part for punching which has good wear resistance and is excellent in long-term reliability.

The invention of claims 5 and 6 does not reduce the tensile stress itself, but by forming a layer harder than other portions on the side surface of the substrate, fatigue due to repeated compressive pressure and tensile stress is reduced. Work to prevent.

[0027]

【Example】

Example 1. FIG. 1 is a sectional view showing a shape near a cutting edge portion of a punch for punching according to a first embodiment of the present invention. In the first embodiment, a coating 3 having a hardness higher than that of the base material 1 is formed on the surface of the cutting edge side surface 2 of the punch made of the base material 1. The cutting edge face 4 of the punch is a horizontal plane 6 in a region between the cutting edge 5 and a portion separated from the cutting edge 5 by a distance 1.2 to 2 times the thickness of the workpiece to be punched.
And a recessed portion 7 in a region of the cutting edge end surface 4 excluding the horizontal plane 6. The base material 1 is made of tool steel, for example. The coating 3 is made of titanium nitride, for example, and has excellent wear resistance. The depth of the depression 7 from the horizontal plane 6 is 0.3 to
It is 10 mm.

Next, with reference to FIG. 1, a method of manufacturing the mold component of the first embodiment will be described. First, the tool steel prepared as the base material 1 is subjected to machining such as cutting, grinding and polishing. As a result, the base material 1 is finished into a desired shape that satisfies the required accuracy. At this time, in order to prevent seizure of the material to be processed and chipping (chipping) of the base material 1 at the time of punching, and to avoid local abrasion and peeling of the coating film 3, the cutting edge side surface 2 and the cutting edge are provided. It is desirable to finish the surface roughness of the base material 1 at a portion of the end face 4 which is in contact with the workpiece to 1 μm. When using a steel material as the base material 1, alloy tool steel (JIS: SKD, etc.)
And high speed tool steel (JIS: SKH) are subjected to heat treatment such as quenching and tempering to prepare them to a desired hardness.
The hardness at this time is Rockwell hardness HRC 58 to 64 in order to secure sufficiently large hardness and appropriate toughness.
It is desirable to set the degree.

Next, using a machining method such as turning, grinding, and drilling, a region other than the horizontal plane 6 in the cutting edge face 4 is dug to form a depression 7. This time,
The width of the horizontal surface 6 from the cutting edge 5 must be 1.2 to 2 times the thickness of the workpiece to be punched. If this width is twice or more the thickness of the workpiece to be punched, the effect of reducing the mass of the substrate 1 in the cutting edge face 4 becomes insufficient,
It is not possible to expect a decrease in the tensile stress that occurs on the cutting edge side surface 2 near the cutting edge of the punch at the moment of breaking the work piece during use of the punch, and therefore it is possible to suppress the fatigue phenomenon of the relevant portion of the base material 1. It will be impossible.

Further, for example, when a mild steel material having a thickness of about 1 mm is punched, the strain distribution in the cutting edge face 4 of the punch has a large value in the region from the edge portion to 0.25 mm. When the width from the cutting edge 5 is 1.2 times or less of the thickness of the workpiece to be punched,
This is inconvenient because the strength near the edge of the cutting edge is insufficient and the base material 1 may buckle or break. In addition, the horizontal surface 6 of the depression 7
If the depth from is less than 0.3 mm, the cutting edge face 4
The effect of reducing the mass of the base material 1 in the inside becomes insufficient, and reduction of tensile stress generated on the cutting edge side surface 2 near the cutting edge 5 of the punch cannot be expected at the moment of breaking the work piece during use of the punch. Therefore, it becomes impossible to suppress the fatigue phenomenon of the relevant portion of the base material 1. Further, if the depth of the depressed portion 7 from the horizontal surface 6 is 10 mm or more, the strength in the vicinity of the cutting edge is insufficient and buckling or breakage of the substrate 1 occurs, which is inconvenient.

Next, processing powder and processing oil are completely removed from the surface of the punch base material 1 finished in a predetermined shape by ultrasonic cleaning with acetone or the like. After that, the substrate 1 is quickly accommodated in the film forming vacuum layer. If a certain period of time is required between the completion of cleaning and the film formation, the substrate 1 is placed and stored in a clean environment such as a desiccator. Such work is important work in order to prevent deterioration of film purity and film adhesion in the film formation in the next step.

Next, for example, the ion plating method
By using a physical film forming method such as a dynamic ion beam mixing method or a chemical vapor deposition method, the cutting edge side surface 2
And on the surface of the cutting edge face 4, TiN, TiC, Cr
A hard coating 3 such as N, TiCN, Al ₂ O ₃ having excellent wear resistance is formed.

Through the above steps, the abrasion-resistant coating 3 formed on the side surface of the cutting edge is prevented from peeling and falling off.
It is possible to obtain a die part for punching which has excellent wear resistance and is excellent in long-term reliability.

In the above embodiment, the physical film forming method or the chemical vapor deposition method is used to form the abrasion resistant film 3, but the hard Cr film is formed by using, for example, the electrolytic plating method. Then, the coating 3 can be easily formed without using a vacuum device. Further, even if the hardness of the surface layer is improved by using the induction hardening method, an effect similar to that of forming the hard coating 3 is achieved.

The punching punch of the first embodiment shown in FIG. 1 is formed by the manufacturing method as described above.

FIG. 2 is a sectional view showing the shape in the vicinity of the cutting edge of a punch for punching according to the second embodiment of the present invention. In the second embodiment, the coating 3 having a hardness higher than that of the base material 1 is formed on the surfaces of the cutting edge side surface 2 and the cutting edge end surface 4 of the punch made of the base material 1. The cutting edge face 4 of the punch is a horizontal plane 6 parallel to the surface of the workpiece to be punched, which has a width 1.2 to 2 times the thickness of the workpiece to be punched from the cutting edge 5 toward the center of the edge face 4. The surfaces adjacent to each other are composed of _one or more inclined surfaces 8 ₁ to 8 _n contacting each other at an angle of 170 degrees or more and less than 180 degrees. The base material 1 is made of, for example, tool steel, the coating film 3 is made of, for example, titanium nitride, and has excellent wear resistance as in the case of the first embodiment.

Example 2. Next, with reference to FIG. 2, a method of manufacturing the mold component of the second embodiment will be described. First, the tool steel prepared as the base material 1 is subjected to machining such as cutting, grinding and polishing. As a result, the base material 1 is finished into a desired shape that satisfies the required accuracy.

Next, using a machining method such as turning, grinding, and drilling, removal processing is applied to the region of the cutting edge end surface 4 excluding the horizontal plane 6 to form inclined surfaces 8 ₁ to 8 _n . The cutting edge surface 4 is composed of a first surface 6 parallel to the surface of the workpiece and second surfaces 8 ₁ to 8 _n inclined with respect to the first surface 6. At this time, the width from the cutting edge 5 of the horizontal plane 6 is
It is necessary to set the thickness to 1.2 to 2 times the thickness of the workpiece to be punched for the same reason as in the first embodiment.
Further, when the angle formed by the inclined surface 8 ₁ adjacent to the horizontal surface 6 or the angle formed by the adjacent inclined surfaces 8 ₁ to 8 _n is smaller than 170 degrees, a portion where the ridge line contacting both surfaces and the cutting edge 5 intersect Since a sharp angle is formed and a concentrated load is applied at the time of punching, there is a problem that chipping of the relevant portion is likely to occur.

Then, in the same manner as in the first embodiment, the punch is cleaned and the hard coating 3 having excellent wear resistance is formed on the surfaces of the cutting edge side surface 2 and the cutting edge end surface 4, and the cutting edge side surface is formed. It is possible to obtain a die part for punching, in which abrasion-resistant coating 3 formed on 2 is prevented from peeling and falling off, has good abrasion resistance and is excellent in long-term reliability.

In the above embodiment, the inclined surfaces 8 ₁ to 8 _n
However, the inclined surface 8 having a curved shape may be formed as shown in FIG. In this case, as the punching process progresses and the cutting edge end face 4 of the punch is pushed into the workpiece, shearing by the cutting edge 5 having the curved shape of the inclined surface 8 proceeds smoothly over time. Since the compressive stress generated inside the punch during this process is dispersed over time, the compressive stress can be reduced as compared with the conventional technique in which the compressive stress is generated all at once. The tensile stress is also dispersed over time and can be significantly suppressed.

By the above manufacturing method, the punching punch of the second embodiment shown in FIG. 2 or 3 is formed.

Example 3. FIG. 4 is a sectional view showing a material structure in the vicinity of a cutting edge portion of a punching punch according to a third embodiment of the present invention. In the third embodiment, in the surface area on the side surface 2 of the cutting edge of the punch made of the substrate 1, the distance from the cutting edge 5 is 0.1 mm to 2.5 mm.
A hardened layer 9 having a hardness higher than that of the base material is formed in a region extending from the surface of the cutting edge side 2 to a depth of 0.4 mm, and the cutting edge includes a region from the cutting edge 5 to the hardened layer 9. A coating 3 having a hardness higher than that of the base material is formed on the side surface of the blade. The base material 1 is made of, for example, tool steel,
The coating 3 is made of titanium nitride, for example, and has excellent wear resistance as in the case of the first embodiment.

Next, with reference to FIG. 4, a method of manufacturing the mold part of the third embodiment will be described. First, the tool steel prepared as the base material 1 is subjected to machining such as cutting, grinding and polishing. As a result, the base material 1 is finished into a desired shape that satisfies the required accuracy.

Next, in the atmosphere, while rotating the punch around the central axis so that the peripheral speed of the surface of the cutting edge side surface 2 becomes 20 mm / sec, the beam center is moved from the cutting edge 5 on the surface of the cutting edge side surface 2. A spot diameter of 5 mm, an output of 1 kW, and a donut mode CO ₂ laser beam are applied to a position of 1.3 mm. As a result, a width of about 2.5 m
A cured film 9 having a thickness of m and a thickness of about 0.4 mm is formed. This time,
In order to increase the CO ₂ laser beam absorptivity of the surface of the substrate 1, anti-reflection processing such as lubrite treatment is necessary.

As shown in FIG. 9, the strain distribution in the cutting edge face 4 of the punch is 0.25 mm from the edge when punching a mild steel material having a thickness of about 1 mm, for example.
Since the value is large in the following region, when the thickness of the hardened layer 9 is 0.3 mm or less, the base material 1 at the time of punching
The effect of suppressing fatigue is insufficient, which is inconvenient. Further, when the thickness of the hardened layer 9 is 0.6 mm or more, the bending strength of the punch surface layer is insufficient and chipping during punching is likely to occur, which is inconvenient. Further, when the area of the hardened layer 9 extends from the cutting edge 5 on the cutting edge side surface 2 to 0.05 mm, the bending strength in the vicinity of the cutting edge 5 is insufficient and punching is performed. The risk of chipping sometimes becomes extremely large, which is practically inconvenient.

Then, in the same manner as in the first embodiment, a hard coating 3 having excellent wear resistance is formed on the surfaces of the punch cleaning and the cutting edge side surface 2 and the cutting edge end surface 4, and the cutting edge side surface is formed. It is possible to obtain a die part for punching, in which abrasion-resistant coating 3 formed on 2 is prevented from peeling and falling off, has good abrasion resistance and is excellent in long-term reliability.

[0047]

According to the first aspect of the present invention, since the recessed portion is provided on the end face of the cutting edge of the substrate facing the workpiece, the tensile stress that acts at the moment of punching the workpiece can be reduced. As a result, fatigue can be suppressed, and the abrasion resistant coating can be prevented from peeling off and falling off.

In the second aspect, the distance from the edge of the cutting edge to the depressed portion is 1.2 to 2 times the thickness of the workpiece, so that the effect of the first aspect can be exerted more effectively.

According to a third aspect of the present invention, a cutting edge end surface of the metal substrate facing the workpiece is provided with a first surface parallel to the workpiece surface and at least one second surface inclined with respect to the first surface. Since the surface is formed, the punching by the first surface and the punching by the second surface are sequentially performed, so that the tensile stress can be reduced. As a result, fatigue can be suppressed, and the abrasion resistant coating can be prevented from peeling and falling off.

According to the fourth aspect of the present invention, the adjoining angles of the plurality of surfaces constituting the cutting edge end face are set to 170 degrees or more and less than 180, so that the effect of the third aspect can be exerted more effectively.

According to a fifth aspect of the present invention, since a harder portion than the other is formed at a predetermined depth on the side surface of the metal substrate at a predetermined distance or more from the cutting edge, fatigue due to repeated compressive stress and tensile stress is caused. Can be suppressed, and the abrasion resistant coating can be prevented from peeling and falling off.

According to the sixth aspect of the present invention, since the harder portion than the side surface of the metal substrate is separated from the edge of the cutting edge by 0.05 mm or more, chipping hardly occurs.

According to a seventh aspect of the present invention, the first step of forming a portion harder than the other at a predetermined depth in a portion separated from the cutting edge of the side surface of the metal base by a predetermined distance or more, and the cutting edge of the metal base is formed. Since the step of forming a coating film harder than that of the metal base on the side surface containing the metal base does not occur, the metal base does not crack or fall off the base material particles. This makes it possible to manufacture a processing member having good wear resistance and excellent long-term reliability.

According to an eighth aspect, at least one of a martensite phase, a nitride, a boride, a carbon compound, a titanium compound and a tungsten compound is formed by locally heating or ion-irradiating a portion harder than the other portions of the seventh aspect. Therefore, it is possible to manufacture a machined member having both a sufficiently high cutting edge strength and wear resistance.

[Brief description of drawings]

FIG. 1 is a sectional view showing a shape near a cutting edge portion of a punch for punching according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a shape near a cutting edge portion of a punching punch according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a shape in the vicinity of a cutting edge portion of another punch for punching according to the second embodiment of the present invention.

FIG. 4 is a sectional view showing a shape near a cutting edge portion of a punch for punching according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing a conventional punch and die for punching.

FIG. 6 is a shape view of a conventional press-type round punch.

FIG. 7 is a sectional view showing a conventional coating punch for punching.

FIG. 8 is a graph showing internal stress generated in the vicinity of a cutting edge of a conventional punch for punching.

FIG. 9 is a graph showing a surface pressure distribution in the vicinity of a cutting edge of a conventional punch for punching.

[Explanation of symbols]

1 Base Material 2 Cutting Edge Side Surface 3 Coating 4 Cutting Edge Edge Surface 5 Cutting Edge 6 First
Surface 7 depressed portion 8 ₁ second surface 8 ₂ second surface 8 _n second surface 9 harder than the other

Claims (8)

[Claims] 1. A base body made of metal, a coating harder than the base material formed on a side surface including a cutting edge of the base body, and a recessed portion at a cutting edge end surface of the base body facing a workpiece. A processing member provided with. 2. The processing member according to claim 1, wherein the distance from the cutting edge to the depression is 1.2 to 2 times the thickness of the workpiece. 3. A metal substrate, a coating harder than the substrate formed on a side surface including a cutting edge of the substrate, and a cutting edge end surface of the substrate facing the workpiece is parallel to the surface of the workpiece. A working member having a first surface and at least one second surface inclined with respect to the first surface. 4. The processing member according to claim 3, wherein adjacent angles of a plurality of surfaces constituting the cutting edge face are 170 degrees or more and less than 180 degrees. 5. A metal substrate having a side portion distant from the cutting edge by a predetermined distance or more and a portion harder than the other at a predetermined depth, and a coating film formed on the side surface of the substrate and harder than the base body. Processing material. 6. The processing member according to claim 5, wherein the predetermined distance is 0.05 mm. 7. A first step of forming a harder portion than a cutting edge at a predetermined depth on a side surface of the metal substrate at a predetermined distance or more from the cutting edge, and a cutting edge of the metal substrate. Second, forming a coating harder than the base on the side surface including the second
The manufacturing method of the member for processing containing the process of these. 8. The method according to claim 7, wherein the second step forms at least one of a martensite phase, a nitride, a boride, a carbon compound, a titanium compound and a tungsten compound by local heating or ion irradiation. Manufacturing method of processing member.