JP5391099B2 - Method and apparatus for forming minute unevenness - Google Patents

Description

  The present invention relates to a method and apparatus for forming minute irregularities on a workpiece (workpiece).

  Conventionally, for example, Patent Document 1 relates to a sliding surface structure, and a slide surface (sliding surface) that is in sliding contact with a thrust load is formed by a special barrel polishing process, and an infinite number of independent minute recesses are randomly formed. It is described that in the presence of a lubricant such as a lubricating oil, the minute depression functions as an oil reservoir so as to reduce the friction coefficient of the sliding surface and improve the seizure resistance.

  Patent Document 2 relates to a sliding surface structure, and a linearly polarized laser is irradiated on the sliding surface to form a grating portion composed of a plurality of concave and convex portions having a predetermined shape and size, thereby reducing the friction coefficient. It is described to do so.

Here, as a method of forming a plurality of minute depressions on the sliding surface, it is assumed that the minute depressions are accurately formed in a short time by pressing.
For example, in Patent Document 3, when a dynamic pressure generating groove is formed in a thrust plate by pressing, pressurization is performed a plurality of times with 80% of the pressing force required to obtain a predetermined groove depth as one pressing force. In doing so, a method is described that enables the formation of a dynamic pressure generating groove having a predetermined depth on the sliding surface while suppressing the overall deformation of the workpiece.

  Further, for example, Patent Document 4 relates to a coining method for forming a predetermined uneven pattern by pressing a punch mold having an uneven pattern on the surface (thrust bearing surface) of the work and deforming the punch mold. Before the step of forming a predetermined concavo-convex pattern, punching is performed by adding a step of forming a raised portion around a portion where a concavo-convex pattern with a sufficient depth cannot be formed only by pressing a punch die. In the coining processing method using a mold, a method is described which enables formation of an uneven pattern having a good depth.

Japanese Patent Laid-Open No. 3-172608 JP 2008-89091 A Japanese Patent Laid-Open No. 5-60127 JP-A-6-254629

  However, when the inventors conducted various research experiments, in the method described in Patent Document 3, for example, when the density of the recesses is increased, 80% of the applied pressure required to form a recess having a desired depth is obtained. Even if the pressure is applied, the workpiece itself is compressed and deformed in the thickness direction (the depth direction of the recess) before the recess having a sufficient depth is formed, thereby forming a recess having a sufficient depth. The occurrence of a phenomenon that it was impossible to do so was confirmed.

  In addition, in the method described in Patent Document 4, since a step of forming a raised portion is added, the manufacturing is complicated, and it is difficult to set a raised amount and the like. As in the method described in Patent Document 3, the workpiece itself is compressed and deformed in the thickness direction (the depth direction of the recess) by the applied pressure, and a recess having a sufficient depth can be formed. There is a fear that it will disappear.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method and apparatus for forming a micro unevenness capable of accurately forming a plurality of micro unevenness while being simple and inexpensive.

For this reason, the method for forming micro unevenness according to the present invention is as follows.
A method for forming a micro unevenness when forming a predetermined number of micro concave portions in a predetermined area of a workpiece using a press device,
While forming the predetermined number of micro concave portions by dividing the number of micro concave portions to be formed at a time smaller than the predetermined number into a plurality of times ,
The number of micro-recesses formed at one time is the product of twice the shear strength of the workpiece and the pressure-receiving area of the die when forming the micro-recesses to the desired recess depth of the micro-recesses. A method for forming fine irregularities, wherein the number is equal to or less than a value obtained by dividing by a forming pressure per one convex portion on the die side determined accordingly .

In addition, the micro uneven forming apparatus according to the present invention,
When forming a predetermined number of minute recesses in a predetermined area of the workpiece,
While forming the predetermined number of micro concave portions by dividing the number of micro concave portions to be formed at a time smaller than the predetermined number into a plurality of times ,
The number of micro-recesses formed at one time is the product of twice the shear strength of the workpiece and the pressure-receiving area of the die when forming the micro-recesses to the desired recess depth of the micro-recesses. The number is equal to or less than the value obtained by dividing by the molding pressure per one convex portion on the die side determined accordingly .
According to such a micro uneven forming method and apparatus according to the present invention, the forming pressure (coining pressure) before the shear depth of the workpiece (workpiece) becomes a predetermined value or more and the recess depth reaches the target, It is possible to avoid the fear that the workpiece (workpiece) yields and the height of the workpiece (workpiece) decreases, making it impossible to form a recess having a predetermined depth. A plurality of minute irregularities with a depth can be accurately formed.

In the present invention, the predetermined region of the object to be processed can be divided into a plurality of shapes and formed.
As a result, the predetermined region of the workpiece (workpiece) has, for example, a complicated shape, an expansion region having a relatively large area, and a region having a relatively small area (for example, a narrow size having a small size in the vertical and horizontal directions). Even in the case where a region and a long and slender region are mixed, a plurality of minute irregularities having a predetermined depth can be accurately formed.

  In the present invention, when a predetermined region of the object to be processed includes a relatively elongated region and a region expanded in the width direction, the region expanded in the width direction is defined as a relatively elongated region. It can be characterized in that it is divided into regions having a width dimension equal to or less than that and molded a plurality of times.

  According to the present invention, it is possible to provide a method and apparatus for forming a micro unevenness capable of forming a plurality of micro unevenness with high accuracy while being simple and inexpensive.

It is a front view which shows roughly the whole structure of the press apparatus (micro uneven | corrugated shaping | molding apparatus) which concerns on one embodiment of this invention. It is a figure which shows typically the punch and several convex part which are used with the press apparatus which concerns on embodiment same as the above. It is a perspective view which shows the outline of a scroll type air compressor. It is a figure which expands and shows the structural example of the fixed scroll of a scroll-type air compressor, a scroll groove | channel, a scroll wrap, and a movable scroll. (A) is a figure which shows the example of 1 aspect at the time of dividing | segmenting A part (expansion area | region) of the fine coining uneven | corrugated shaping | molding part of the workpiece | work which concerns on embodiment same as the above according to the width dimension of B part (elongate area | region). is there. It is a figure which shows an example of the punch used in the example of FIG. (A) is a figure which shows the FEM calculation result of the stress which arises in each recessed part of a workpiece | work when dividing | segmenting a shaping | molding area | region like the example of FIG. 5 (A), and (B) is FIG.5 (B). It is a figure which shows the FEM calculation result of the stress which arises in each recessed part of a workpiece | work in the case of shape | molding by pressing the whole forming area | region uniformly like the example of. (A) is a diagram schematically showing a deformation mode of a work when forming a relatively narrow forming width with a corresponding punch width when forming a portion having no (or less) surplus around the punch, (B) is a figure which shows typically the deformation | transformation aspect of the workpiece | work at the time of shape | molding a comparatively wide shaping | molding width | variety with an appropriate punch width | variety, when shape | molding the site | part which does not have surplus around a punch. (A) is a figure which shows typically the deformation | transformation aspect of the workpiece | work at the time of shape | molding a comparatively narrow shaping | molding width | variety with a suitable punch width | variety, when shape | molding the site | part which has surplus around a punch, (B) It is a figure which shows typically the deformation | transformation aspect of the workpiece | work at the time of shape | molding a comparatively wide shaping | molding width | variety with a suitable punch width | variety, when shape | molding the site | part with a surplus margin around a punch.

  Hereinafter, a method and apparatus for forming a micro unevenness according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  On the workpiece surface, the depth is about several thousandths of a millimeter (more specifically, for example, about 0.002 to 0.01 mm), and the diameter is about a few millimeters (more specifically, for example, φ0 In the press working that forms a plurality of minute recesses of about .1 to 0.2 mm), when the press work is performed by position control that controls the position of the die, the workpiece material thickness is on the order of several thousandths of mm or less. In reality, it is difficult to supply a workpiece controlled with high accuracy, so in actual press work, pressure control that controls the press pressure can be adopted. Many.

  However, when press working is performed under pressure control, a plurality of small concave portions having a depth of about several thousandths of a millimeter and a diameter of about several millimeters are formed on the workpiece surface in the order of thousands or tens of thousands. If an attempt is made to increase the number of minute recesses, the thickness of the workpiece itself (thickness in the direction along the direction of action of the pressing force) becomes thinner due to plastic deformation, with a certain value as a boundary. The inventors have confirmed through experiments and the like that a phenomenon occurs in which minute irregularities having a desired depth cannot be accurately formed.

  Such a phenomenon is caused by the relationship between the punch stress applied to the minute unevenness forming portion of the workpiece surface and the average stress when the punch stress is viewed as the entire workpiece.

That is, for example, if the punching surface pressure required to mold one recess having a depth of 0.005 mm and a size of φ0.2 mm on the workpiece surface is 700 MPa, the molding force is 22 N (= (0.2 mm × 0 2 mm × π / 4) × 700 N / mm ² ) is required.

For example, if one such recess is formed on a workpiece having a size of φ9 mm, height (thickness) H = 4 mm, and shear resistance (shear strength) of 161 MPa, the average stress acting on the entire workpiece is:
22N / (9 ² mm ² × π / 4) = 0.35 MPa, and no stress that changes the height of the entire workpiece is generated.

  However, when the number of concave portions to be formed increases and exceeds a certain number, a stress that reduces the workpiece height is generated. Such reduction in the workpiece height during molding pressurization makes it difficult to mold a recess having a desired depth.

  The press apparatus and method for forming minute irregularities according to the present invention are made from such a viewpoint, and enable a plurality of minute irregularities to be accurately formed.

  FIG. 1 schematically shows the overall configuration of a press apparatus (micro unevenness forming apparatus) 1 for forming micro unevenness according to the present embodiment.

  An upper die (die) 20 is attached to the lower part of the slide 10 which is connected to the reciprocating mechanism of the pressing device 1 and reciprocated (pressed).

  A lower mold 30 is provided opposite to the upper mold 20 that is reciprocated via the slide 10, and the lower mold 30 is supported by the cushion device 40, and the cushion device 40 is connected to the press device 1 via the bolster 50. Are supported by a frame (not shown).

  A punch 21 for forming predetermined minute irregularities on the work 2 is attached to the lower surface of the upper mold 20, and the work 2 is supported on the upper surface of the lower mold 30 on the opposite side across the work 2. A die 31 is attached.

  As shown in FIGS. 2 (A) and 2 (B), the lower surface of the punch 21 has a plurality of protrusions 22 that protrude from the workpiece 2 to form a plurality of minute irregularities having a predetermined depth. Is formed. The convex portion 22 can be formed by a technique such as etching.

  More specifically, for example, the punch 21 is an SUS632 aging-treated product, and can be composed of a metal plate-like element having a thickness of about 0.15 mm to 0.2 mm. For example, about 10,000 protrusions having a diameter of 0.2 mm are formed as a plurality of convex portions (coining punches) 22 on the facing surface by etching or the like. 2A and 2B, the display of the protrusions 22 is simplified, and a part of the plurality of protrusions 22 is extracted and enlarged and schematically displayed. The punch 21 may be manufactured from a hardened and hardened product of SUS420J2 or SUS440C.

  As the workpiece 2, an element having a sliding surface (sliding surface) that comes into sliding contact with a thrust load, for example, a thrust bearing or a scroll such as a scroll compressor made of a material corresponding to FC250 can be assumed. .

  Here, as shown in FIG. 3 and FIG. 4A, the scroll compressor includes a fixed scroll 51 having a spiral scroll groove 51A, a groove side surface of the scroll groove 51A, which is accommodated in the scroll groove 51A, and a predetermined width. A movable scroll 52 having a spiral scroll wrap 52A that engages with a gap is disposed facing each other, and by rotating the movable scroll 52 relative to the fixed scroll 51, the groove side surface of the scroll groove 51A and the scroll wrap 52A are arranged. The compressed air is discharged from the discharge port by compressing the air in the predetermined gap with the side surface.

  Here, the contact surfaces of the fixed scroll 51 and the movable scroll 52 in the facing direction are slid at a relatively high speed (sliding contact) while maintaining contact with a predetermined surface pressure in order to maintain airtightness. Therefore, for example, minute irregularities are formed on the contact surface of the fixed scroll 51 (or / and the movable scroll 52) (corresponding to the workpiece 2) to reduce the friction coefficient of the sliding surface and improve the seizure resistance. It is hoped that

  When a fixed scroll 51 is assumed as the workpiece 2, as shown in FIGS. 4 (A) and 4 (B), the area where the minute unevenness is to be formed is near the portion A of the sliding surface of the workpiece 2. This is an extended region that is expanded in the lateral direction along the moving surface (region that spreads relatively evenly in each direction), and in the vicinity of the portion B, an area where the minute irregularities are to be formed is an elongated region.

  An experiment conducted by the inventor using the press apparatus 1 shown in FIG. 1 including the case where minute unevenness is formed on a workpiece in which such an extended region and an elongated region are mixed will be described below.

In the experiment, the fixed scroll 51 of the scroll compressor is used as the work 2, and the minute coining concavo-convex molding portion (the inner region of the two-dot chain line X in FIG. 1900 mm ² ), 40900 recesses with a diameter of 0.20 mm are formed at a depth of 0.01 ± 0.002 mm.

  The mold used is a mold corresponding to a part for forming minute irregularities using a flat die 31 and a punch 21 having minute projections as shown in FIGS. 2 (A) and 2 (B). Corresponding minute irregularities are formed on the part of the mold, and the mold corresponding to the part where the minute irregularities are not molded is made thinner than the thickness of the penetration or the concave part so that it does not contact the workpiece 2 during molding. It is configured.

The total area (area of the fine coining unevenness forming portion X) of the A portion (area expansion region) and the B portion (elongated region) shown in FIG. 4A is 1679 mm ² , and the ratio is about 3 : 7 (= A part area: B part area) and 504 mm ² : 1175 mm ² .
In addition, the number of recessed portions formed in the A part and the B part is A part: B part = 1270 pieces: 28630 pieces (= 3: 7).

(1) 28630 minute convex portions (coining punches) 22 are formed in a portion corresponding to the B portion of the workpiece 2 of the punch 21, and the depth of the concave portion in the B portion of the workpiece 2 using the punch 21. An experiment was conducted in which the coining pressure (molding pressure) was increased via the hydraulically driven cushion device 40 shown in FIG.
As a result, when the work stress of the B1 part (see FIG. 4B) in the B part of the work 2 shown in FIG. 4A becomes 335 MPa, the work height of the B part decreases by 0.05 mm. Thus, the depth of the recessed portion thus formed was limited to 0.008 mm, and the target of the recessed portion depth of 0.01 mm could not be achieved.
This is because the coining pressure exceeded 322 MPa, which is twice the shear strength of 161 MPa of the work 2, so that the material (work 2) yielded before the recess depth reached the target, and the B of work 2 It is thought that the height of the part decreased.

(2) Next, as a result of experimentally determining the punch forming surface pressure (σ) at which the recess depth of the workpiece 2 is 0.01 mm, which is the target, it was obtained that σ = 1640 MPa. Therefore, the molding load in the case of molding a recess having a diameter of 0.2 mm is p = 52N.
Twice the shear strength of the workpiece 2 is 322 MPa, and the die area (die pressure receiving area) (S = B1 portion) that receives the pressing of a plurality of coining punches (small convex portions formed on the punch 21) 22 is 1175 mm. ^Since the thickness of the workpiece 2 does not decrease (the workpiece 2 does not yield), if the number of coining punches is n,
Since 2τ> pn / 1175, from n <1175 × 2τ / p,
The coining punch number n is 7276 (pieces) or less.
Therefore, since 28630 (pieces) / 7276 (pieces) = 3.9, the die area is not changed and the coining punch density is set to about ¼ so that 28630 (pieces) are formed in four times (steps). The number of punches is 7157 twice and 7158 twice (7157 × 2 + 7158 × 2 = 28630), and the punch position is changed in each process (even if punches 21 having different punch positions are prepared for each process) (Alternatively, the punch 21 is common to each process, but the mounting position or the mounting position of the work 2 may be changed.) By forming, the thickness of the work 2 is not reduced in the B part. It is considered that a predetermined number (28630) of minute recesses can be formed.
Therefore, when an experiment was performed in which a predetermined number (28630) of minute recesses were formed in four steps, a minute recess having a depth of 0.01 mm ± 0.002 mm was formed in B portion (elongated region) of the work 2. Individual molding was possible, and the thickness of the workpiece 2 was not reduced.

  (3) Next, so that the A part and the B part of the work 2 can be formed in four times (steps), the die surface pressure is unchanged for the A part of the work 2 and the coining punch density is reduced to 1/4. The number of coining punches in the A portion per time is 3067 twice, 3068 twice (3067 × 2 + 3068 × 2 = 1270), the number of coining punches in the A portion + the number of coining punches in the B portion = 3068 The punch position is changed in each step by the number of +7157 pieces = 10225 minute convex portions (coining punches) 22 (a punch 21 having a different punch position may be prepared for each step, or common to each step) Although the punch 21 is mounted, or the mounting position of the workpiece 2 may be changed), the punching was performed with a surface pressure of punch surface pressure σ = 1640 MPa.

  As a result, the depth average of the recesses formed in the A portion is about 0.005 mm, the depth average of the recesses formed in the B portion is about 0.013 mm, and the recesses formed in the A portion and the B portion It was confirmed that there was a large variation in the depth of the recesses between the recesses formed in the above.

  This is because the area where the coining punch (small convex portion) 22 is installed is larger in the A portion (expanded region) than in the B portion (elongated region). The total amount of elastic deformation of the mold) is larger in the A portion than in the B portion. As a result, the average recess depth in the A portion (expanded region) is shallower than the average recess depth in the B portion (elongated region). (See the work stress generation mode (substantially equally distributed load) in FIG. 2B, the stress variation shown in FIG. 7, the work deformation mode shown in FIG. 9).

  In other words, the value obtained by dividing the load applied to the entire workpiece by the total area of all punches is 1640 MPa, but actually, the punch surface pressures different in the A portion at the outer peripheral portion and the inner portion of the A portion due to the reasons described above. Therefore, it is considered that the surface pressure of 1640 MPa or more is applied to the portion B because the punch surface pressure of the inner portion of the portion A is low. It is considered that a variation in the depth of the concave portion was generated between the concave portion formed into the concave portion and the concave portion formed into the B portion.

(4) From the results of (1) to (3) described above, the present inventor has arranged the arrangement area (arrangement) of the plurality of coining punches 22 arranged on the punch 21 corresponding to the A portion of the workpiece 2. (Region: die pressure receiving area) is divided into an area (region) equivalent to the arrangement area (arrangement region: die pressure receiving area) of the plurality of coining punches 22 arranged corresponding to the part B of the work 2. I tried to mold it.
As a result, it was confirmed that the concave part of the A part and the concave part of the B part can be molded at a depth of 0.01 mm ± 0.002 mm.

  This is because the arrangement area (arrangement region) of the plurality of coining punches 22 corresponding to the A portion of the workpiece 2 is changed to the arrangement area (arrangement region) of the plurality of coining punches 22 corresponding to the B portion of the workpiece 2. 9A (for example, by reducing the arrangement area of the coining punch 22 from FIG. 9B to FIG. 9A), as shown in FIG. Compared to 9 (B), the amount of elastic deformation of the work 2 can be made substantially equal between the A part and the B part by reducing the amount of deflection of the inner part due to the bending deformation that occurs in the expansion region. When a punch surface pressure σ = 1640 MPa is applied, a surface pressure of 1640 MPa is applied to the B portion, and a surface pressure of 1640 MPa is equally applied to the A portion. Variation is suppressed, part A and B It is believed that it was possible to accurately shape the minute recesses in both depth 0.01 mm ± 0.002 mm.

Thus, this experiment
For part B (elongated area), the molding process is divided into four times, and the entire part B is covered with the same density, but the coining punch position is different while covering the entire elongate area of part B. A predetermined number of recesses having a desired depth are formed in
As for the A part (expanded area), the A part (expanded area) is divided into a plurality of parts so that the area of the A part to be formed in one molding is equivalent to the elongated area of the B part (for example, FIG. 5). (A), as shown schematically in FIG. 5 (B) and FIG. 6, the number of coining punches is set so that each divided area has the same surface pressure as the area B. It was confirmed that it was possible to form a predetermined number of recesses having a desired depth in the entire portion A by performing molding on different regions for each process using the punch 21 thus prepared.

  Here, depending on the setting conditions such as the area of the A part and the B part, the number of micro unevenness (coining punch number) and the depth of the concave part, the number of divisions of the area of A part and the number of divisions of the molding process of B part are It is assumed that the entire area of the A part and the B part cannot be molded as desired with the same number of moldings. By setting the number of coining punches and the punch area so as not to reduce the thickness, the entire area of the A part and the B part can be formed as desired.

  When a relatively elongated area and a relatively expanded area are mixed in a predetermined area of the workpiece (workpiece), the relatively expanded area is relatively elongated. It can also be set as the structure divided | segmented into the area | region below the width dimension equivalent to an area | region, and shape | molding in multiple times.

  For example, when there is an unformed region of a recess in the A portion with the same number of moldings as the B portion, the remaining region of the A portion is formed with the number of coining punches that does not reduce the thickness of the work 2. Thus, a predetermined number of recesses having a desired depth can be formed on the entire A portion.

  By the way, as described in the above item (3), the present inventors have confirmed the existence of a phenomenon in which the depth variation of the recesses occurs in the outer peripheral portion and the inner portion of the portion A (expanded region). Etc. obtained the following knowledge as a result of attempting a more detailed analysis of this phenomenon by FEM calculations, experiments with actual machines, and the like.

  That is, for example, even if the same load is applied using the punch 21 having the same convex density as shown in FIGS. 5A and 5B and FIG. It was clarified that the stress generated in the portion pressed by the convex portion (coining punch 22) is different (see FIGS. 7A and 7B).

  In the case of FIG. 5B, since the load is applied to all of the elongated regions, the entire molding region undergoes plastic deformation after causing uniform elastic deformation. Therefore, as shown in FIG. The stress applied to the (coining punch 22) is substantially uniform.

  On the other hand, in the case of FIG. 5 (A), since there is a surplus around the molding region, bending deformation occurs in the molding region, and the amount of deflection of the inner portion is larger than that of the outer peripheral portion. Thus, the stress applied to the convex part of the inner part is smaller than that of the outer peripheral part.

  That is, as shown in FIGS. 8A and 8B, when there is no surplus around the convex portion (coining punch 22) of the punch 21, the work 2 is extended and the entire forming region is uniform. Therefore, it is possible to form a plurality of recesses with high accuracy with little variation in the depth of the recesses to be formed. However, as shown in FIG. 9A and FIG. When there is a relatively large amount of surplus around the (coining punch 22) (for example, when forming the portion A (extended region) in FIG. 4 by dividing the forming region as shown in FIG. 5A). In other words, bending deformation occurs in the work 2 and the amount of deflection of the inner portion of the punch 21 becomes larger than that of the outer peripheral portion.

  For this reason, in order to form a plurality of concave portions with high accuracy, it is required to suppress variation in the depth of the concave portions between the outer side and the inner side portion of the punch 21. However, FIG. 9A and FIG. As shown in FIG. 9B, for example, as shown in FIG. 9B, the amount of deflection (and thus the variation in the depth of the recesses in the outer and inner portions) decreases as the width L of the punch 21 is reduced. In addition, the width L (that is, the vertical size or the horizontal size) of the punch 21 may be set so that the deflection amount of the work 2 in the outer portion of the punch 21 is within the range of the product tolerance of the recess depth. desirable.

  As a result, when there is a relatively large amount of surplus around the convex portion (coining punch 22) of the punch 21 (for example, the portion A (extended region) in FIG. 4 is divided into the forming region as shown in FIG. 5A). Even in the case of molding, the amount of internal deflection between the outer and inner portions of the punch 21 is larger than that of the outer peripheral portion, and the depth variation of the recesses between the outer and inner portions of the punch 21 increases. Occurrence of the phenomenon can be suppressed, so that a plurality of concave portions can be formed with high accuracy.

  In addition, according to the present invention, even in a case where an extended region having a relatively large area and a region having a relatively small area are mixed in a predetermined region of the workpiece (workpiece), a plurality of predetermined depths are provided. Although minute irregularities can be accurately formed, the elongated region has been described as a representative example in this embodiment as a region having a relatively small area. However, the present invention is not limited to this, for example, in the vertical and horizontal directions. The present invention can also be applied to a narrow region having a small size.

  In addition, various modifications can be made without departing from the scope of the present invention.

  According to the method and apparatus for forming micro unevenness according to the present invention, it is advantageous that a plurality of micro unevenness can be accurately formed while having a simple and inexpensive configuration.

1 Press device (micro uneven forming device)
2 Workpiece (processed object)
10 Slide 20 Upper mold (mold)
21 Punch 22 Coining punch (small convex part)
30 Lower mold 40 Cushion device 50 Bolster

Claims (6)

A method for forming a micro unevenness when forming a predetermined number of micro concave portions in a predetermined area of a workpiece using a press device,
While forming the predetermined number of micro concave portions by dividing the number of micro concave portions to be formed at a time smaller than the predetermined number into a plurality of times ,
The number of micro-recesses formed at one time is the product of twice the shear strength of the workpiece and the pressure-receiving area of the die when forming the micro-recesses to the desired recess depth of the micro-recesses. A method for forming fine irregularities, wherein the number is equal to or less than a value obtained by dividing by a forming pressure per one convex portion on the die side determined accordingly . 2. The method for forming fine irregularities according to claim 1, wherein the predetermined region of the object to be processed is formed by being divided into a plurality of parts. When a relatively elongated area and an area expanded in the width direction coexist in a predetermined area of the workpiece, the area expanded in the width direction is equal in width to the relatively elongated area. The method according to claim 2 , wherein the fine unevenness forming method according to claim 2 , wherein the fine unevenness forming method is performed in a plurality of times by dividing into regions having dimensions or less. When forming a predetermined number of minute recesses in a predetermined area of the workpiece,
While forming the predetermined number of micro concave portions by dividing the number of micro concave portions to be formed at a time smaller than the predetermined number into a plurality of times ,
The number of micro-recesses formed at one time is the product of twice the shear strength of the workpiece and the pressure-receiving area of the die when forming the micro-recesses to the desired recess depth of the micro-recesses. A micro uneven forming apparatus characterized in that the number is equal to or less than a value obtained by dividing by a forming pressure per one convex portion on the die side determined accordingly . The micro uneven | corrugated shaping | molding apparatus of Claim 4 which divides | segments and shape | molds the predetermined area | region of a to-be-processed object into plurality. When a relatively elongated area and an area expanded in the width direction coexist in a predetermined area of the workpiece, the area expanded in the width direction is equal in width to the relatively elongated area. 6. The micro uneven forming apparatus according to claim 5 , wherein the micro uneven forming apparatus according to claim 5 , wherein the micro uneven forming apparatus is divided into regions having dimensions or less and is formed a plurality of times.