JPH03138032A - Pressing method for sheet metal parts, working method for die and its die - Google Patents

Abstract

PURPOSE:To omit the finishing process and to press the plate to the required shape without any obstacle by cutting the contact surface of the die with the sheet metal parts by a small pitch with the machine tool, forming the prescribed shape and then pressing the sheet metal parts. CONSTITUTION:The contact surface 4a of the die 4 of the upper die 2 is formed in the state of mirror finished surface with grinding. Next, the contact surfaces 6a and 7a of the blank holder 7 and the punch 6 of the lower die 1 are cut while moving the cutter 10a of the machine tool by a small pitch. At this time, because the cutter 10a machines by a small pitch, so the mountain part 12 of cut remainder are caused to remain. Next, the cutter 10a is shifted its position by a half interval of the pitch p and executes work of cutting, by which the cut remainder mountain parts 12 are cut off and formed to the trapezoid shape and the smooth surface of small ruggedness is formed, and so the pressing work of the required shape is executed without any obstacle.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for press forming sheet metal parts such as aluminum alloy plates and steel plates, a method for processing a mold used for the press process, and a mold for the press process.

(Prior Art) Conventionally, relatively large molds used for press working of sheet metal parts with smooth surfaces, such as inner and outer parts of automobiles, are usually made by making a model of the mold using styrofoam. Next, after applying a resin solvent to form a hardened layer on the surface, the model is surrounded with sand, and in this state, the mold is made by the so-called FMC method, in which molten metal made of iron-based material is injected and Styrofoam etc. are burned. A blank mold is manufactured, and then the surface of the blank mold is sequentially subjected to rough machining, finishing machining, polishing, etc., thereby manufacturing a desired mold that takes into account springback, elongation, etc. of the sheet metal part. The molds manufactured in this manner are usually used to press sheet metal parts on a trial basis to perform quality inspections, etc., and then are actually used in automobile production lines or the like.

In addition, in manufacturing this type of mold, the contact surface of the mold that comes into contact with the sheet metal part during press processing is used to prevent distortions, scratches, etc. from occurring in the sheet metal part and to prevent its smoothness from being impaired. In order to make the bent parts of the sheet metal parts in the press process slide against the contact surface of the mold and easily deform, the contact surface is polished until it becomes a mirror surface. BACKGROUND OF THE INVENTION In molds used for press working of sheet metal parts, such as outer panel parts, which require high precision surface smoothness, the contact surfaces are carefully polished. In recent years, devices have been developed that automatically perform this polishing process when the contact surface of the cough mold has a relatively flat shape, but when the contact surface has a relatively complex curved shape, Currently, this is still done manually.

However, since the contact surface of the mold is manually polished in this way, the polishing process requires a great deal of labor and time, which has been an obstacle to improving the manufacturing efficiency of the mold.

In addition, in such manual polishing, distortions may occur due to subtle waviness in the shape of the contact surface of the mold due to differences in the skill level and experience of the workers. When press working a sheet metal part, there is a risk that the sheet metal part may not be reliably machined into a desired shape, such as the smoothness of the sheet metal part being impaired. In order to prevent distortion of the contact surface of the mold, the sheet metal parts are pressed on a trial basis as described above, and the contact surface of the mold is polished again according to the results. However, this polishing process often requires several corrections, which adds to the time required to manufacture the mold and, in turn, prevents the mold from being used in automobiles. This caused a delay in the schedule for putting the product on the production line.

(Problems to be Solved) The present invention eliminates such inconveniences, reduces the time required from manufacturing a mold to pressing a sheet metal part using a mold, and also makes it possible to It is an object of the present invention to provide a press working method that allows processing into a desired shape without any problems.

In addition, the contact surface of the mold that can process the sheet metal part into a desired shape without any problems can be efficiently formed without manual polishing. The purpose is to provide a mold processing method.

Further, it is an object of the present invention to provide a mold machined by the mold processing method, which can hold the surface of the sheet metal part smoothly with high precision during press working of the sheet metal part using the mold. purpose.

Furthermore, it is possible to further improve the slipperiness of the contact surface of the welding die, where slipping occurs between all parts of the plate during press working of sheet metal parts, in a die machined by the die processing method. The purpose of the present invention is to provide a mold that can improve the durability of the mold.

(Means for Solving the Problems) As a result of various studies, the inventors of the present invention found that sheet metals, such as inner panel parts of automobiles, which do not require very high precision in shape and surface smoothness due to press working, In press working of parts, if the contact surface of the mold for press working with the sheet metal part is cut into a predetermined shape at a sufficiently small pitch, the height of the unevenness created on the contact surface by the cutting process can be reduced. can be made sufficiently small, and therefore, the die after cutting can be used as is to press the sheet metal part into the desired shape while maintaining the required surface smoothness. We learned that it is possible.

For example, even in sheet metal parts such as automobile exterior parts that require relatively high precision in shape and surface smoothness due to press processing, the contact surface of the mold after the cutting process has a high degree of unevenness. Specifically, the height of the unevenness is made sufficiently small relative to the thickness of the sheet metal part for sheet metal parts with a thickness of 0.6 to 1.2 pans, which are often used in automobile exterior parts. If the sheet metal part is processed so that the surface roughness is 2% or less of the sheet metal part, the welding die can be used as is to press the sheet metal part into the desired shape while maintaining the required smoothness of the surface. It has been found that it is possible to maintain the smoothness of the surface of the sheet metal part that does not come into contact with the contact surface of the welding die with high precision.

Therefore, in order to achieve the above object, the press working method for sheet metal parts of the present invention is a step of forming the contact surface of the mold with the sheet metal part into a predetermined shape by cutting the contact surface with the sheet metal part with a machine tool at a small pitch. and a step of pressing the sheet metal part using a mold obtained by omitting the finishing step of the contact surface after the cutting.

In order to achieve the above object, the method for processing a mold of the present invention is a method for processing a mold for press working a sheet metal part, in which the contact surface of the mold with the sheet metal part is machined. It is characterized by being formed into a predetermined shape required for press working by cutting with a machine at a small pitch.

Furthermore, the present invention is characterized in that, after the cutting process, a step of polishing or cutting the uncut mountain portions remaining between the cut portions of the contact surface into a substantially trapezoidal shape is provided.

Alternatively, the method is characterized in that a step of applying a solid lubricant to the cut portion of the contact surface is provided after the cutting process.

Further, the mold of the present invention is a mold for press working a sheet metal part having a thickness of 0.6 to 1.2 mm, and includes a step of polishing or cutting the uncut mountain portion into a substantially trapezoidal shape. The present invention is characterized in that the uncut ridges are polished or cut to a height of 2% or less of the thickness of the sheet metal part using a mold processing method.

Alternatively, the height of the uncut mountain portion from the solid lubricant applied to the cutting portion by a mold processing method comprising the step of applying the solid lubricant to the contact surface may be determined by the thickness of the sheet metal part. A mold characterized in that the amount is 2% or less.

Furthermore, in a mold processed by such a mold processing method, plating with chromium, nickel, etc. is applied at least to a portion of the contact surface where slippage occurs between the sheet metal part and the sheet metal part during press working of the sheet metal part. It is characterized by having undergone

Alternatively, the contact surface is coated with a solid lubricant containing molybdenum, carbon, or the like.

(Function) According to the press working method for sheet metal parts of the present invention, after cutting the contact surface of the mold with the sheet metal part with the machine tool at a small pitch, the sheet metal part is manufactured using the mold as it is. Since press working is performed, the manual work of polishing the contact surface of the mold is omitted, making it possible to shorten the time from manufacturing the welding mold to pressing using the mold. In this case, the contact surface of the welding die can be formed into a smooth surface with sufficiently small irregularities by cutting at a small pitch, and therefore, the shape and surface smoothness caused by press working are not too great. For sheet metal parts that do not require high precision, it is possible to press them into a desired shape with sufficient precision while maintaining surface smoothness.

According to the mold machining method of the present invention, the contact surface of the mold is cut at a small pitch by the machine tool in the same manner as described above, thereby omitting manual polishing of the sheet metal part. Since the contact surface is formed into a predetermined shape required for press working, it is possible to form the contact surface in a short time, and by cutting the contact surface at a small pitch, it is possible to form a smooth surface with sufficiently small irregularities. It is possible to form it on a surface.

In this case, the height of the unevenness of the contact surface is further reduced by polishing or cutting the uncut mountain portions remaining between the cut portions of the contact surface into a substantially trapezoidal shape after the cutting process, It is possible to form a smoother contact surface.

Alternatively, even if the solid lubricant is applied to the contact surface after the cutting process and the solid lubricant is applied to the cut portion of the contact surface, the height of the uncut mountain portion may be higher than the cut portion. As a result, the height of the unevenness on the contact surface is further reduced,
It is possible to form a smoother contact surface.

Further, according to the mold for press working a sheet metal part having a thickness of 0.6 to 1.2 mm of the present invention, the uncut mountain portion is polished or cut into a substantially trapezoidal shape, or the cutting By applying the solid lubricant to the location, the height of the uncut peaks is set to 2% or less of the thickness of the sheet metal part, so that the contact surface is formed smoothly with high precision. Using the mold, it is possible to press the sheet metal part into a desired shape with high precision while maintaining surface smoothness. In particular, during the press working, the surface of the sheet metal part that does not come into contact with the contact surface is hardly affected by slight irregularities on the contact surface, and the smooth state before the press work is maintained.

In addition, in a mold processed by the above-mentioned mold processing method, when plating with chromium, nickel, etc. is applied to the portion of the contact surface where slippage occurs between the sheet metal part and the sheet metal part, a friction mold is used to plate the contact surface with chromium or nickel. When press working sheet metal parts, the plated parts have better sliding properties, making it easier to deform the sheet metal parts into the desired shape, and reducing wear on the contact surfaces of the molds. Decrease.

This also applies when the solid lubricant is applied to the contact surface of the mold.

(Example) An example of a press working method of a sheet metal part, a working method of a metal mold, and a mold thereof according to the present invention will be explained with reference to FIGS. 1 to 4. Fig. 1 is an explanatory cross-sectional view of the entire press molding device;
4 to 4 are explanatory diagrams for explaining a method of processing a mold of the press molding apparatus.

In FIG. 1, 1 is a lower mold, 2 is an upper mold that is lowered toward the lower mold 1, and the upper mold 1 is provided with a die 4, which is a metal mold, on the lower surface of a ram 3.

The lower mold 1 includes a bunch 6 which is a mold provided on a bolster 5.
and a blank holder 7, which is a mold, which is fitted onto the punch 6 so as to be able to rise and fall freely, and the blank holder 7 is urged toward the upper die 2 via a cushion pin 8.

In this press forming apparatus, as shown in the first figure, a sheet metal part W to be press-worked, specifically, a sheet metal part W having a thickness of 0.7 m with a smooth surface used for interior and exterior parts of automobiles, etc.
An iron plate m is mounted on the contact surface 7a formed on the upper surface of the blank holder 7 and in contact with the sheet metal part W, and in this state, the upper mold 2 is lowered toward the lower mold.

At this time, the die 4 of the upper die 2 first contacts the sheet metal part W at the position of the blank holder 7 with the contact surface 4a formed on the lower surface thereof, which contacts the sheet metal part W, and the blank holder 7 and the sheet metal part W. is pressed down, whereby the center portion of the sheet metal part W comes into contact with a contact surface 6a formed on the upper surface of the punch 6 and with the sheet metal part W.

Next, as the upper mold 2 descends, the sheet metal part W is pressed between the contact surface 6a of the bunch 6 and the contact surface 4a of the die 4, and is bent to follow the shape of both contact surfaces 6a, 4a. and molded into a predetermined shape. After the molding, the sheet metal part W
The surfaces of the four dies are painted.

In such a press forming apparatus, the die 4 is manufactured by the conventional method described above, and its contact surface 4a is polished.
l) Formed into a mirror surface, bunch 6 and blank holder 7
were manufactured by applying the processing method of the present invention to these contact surfaces 6a and 7a as described below.

Next, a method of processing the contact surface 6a of the bunch 6 will be explained with reference to FIGS. 2 to 4.

When manufacturing the bunch 6, first, the material mold 9 shown in the second figure was created by the above-mentioned FMC method.

Next, the upper surface of the material mold 9 is machined, for example, by an NC machine tool 10 into which predetermined shape data has been input, as shown in FIGS. 2 and 3.
It was cut to have substantially the same shape as the contact surface 6a of the bunch 0.

Specifically, in this example, the tool diameter R=
N equipped with a 50φ ball end mill cutter 10a
Using the C machine tool 10, cutter 10a is set at pitch P.
= 1 mm, and the upper surface of the blank mold 9 was cut according to the above shape data while moving along the upper surface.

At this time, as shown in FIG. 3, the cutter 10a cuts the upper surface of the blank mold 9 at a pitch P = 1 mm, so there are uncut peaks 12 between the cut locations 11 of the blank mold 9 by the cutter 10a. remains, and its height h is 0.01 to 0.
．． It was 04mm.

The upper surface of the material mold 9 cut in this way is then shot blasted using, for example, a blasting device 13 as shown in the fourth figure to polish the uncut ridges 12 to give it a rounded shape. It is approximately trapezoidal.

More specifically, in this shot blasting, the injection nozzle 13a of the blasting device 13 is moved along the upper surface of the blank mold 9 at the pitch 1 rail, using the shape data in the cutting process, and each uncut ridge is 12, the uncut mountain portion 12 was polished into a substantially trapezoidal shape by spraying an abrasive material 14 from the spray nozzle 13a. At this time, the height H from the material mold 9 of the injection nozzle 13a and the inclination angle θ with respect to the material mold 9 are controlled to be constant at all times, and the jetting time of the abrasive 14 is appropriately controlled. The height h of each uncut mountain portion 12 is 2% or less of the thickness of the sheet metal part W, that is, 0.014 mm.
Polished until the following. Through this polishing process, the upper surface of the blank mold 9 became the contact surface 6a, thereby obtaining the bunch 6. In this case, the height of the unevenness of the contact surface 6a, that is, the height h of the uncut peak portion 12 is 0.01% or less of the thickness of the sheet metal part W as described above.
Since it is 4 mm or less, the contact surface 6a is a highly precise and smooth surface.

On the other hand, the blank holder 7 was manufactured in exactly the same manner as the bunch 6, and its contact surface 7a was processed as described above to form a highly accurate and smooth surface.

In the press forming apparatus equipped with the bunch 6, blank holder 7, and die 4 manufactured as described above, the contact surfaces 6a, 7a of the bunch 6 and blank holder 7 are formed into highly precise and smooth surfaces as described above. Along with being
Since the contact surface 4a of the die 4 is formed into a mirror surface, when the sheet metal part W is pressed as described above, the surface of the sheet metal part W is hardly distorted or scratched, and its smoothness is maintained. Then, the sheet metal part W could be pressed into a desired shape.

After the press working, when the surface of the four dies of the sheet metal part W, that is, the surface that does not come into contact with the bunch 6 and the blank holder 7, is painted, the height of the unevenness of the painted surface is, for example, It fell within the range of 0.1 mm or less, which is considered a good painted surface for a plate part. This means that
As described above, by polishing the uncut peaks 12 of the contact surfaces 6a and 7a of the bunch 6 and the blank holder 7 until the height h becomes 2% or less of the thickness of the sheet metal part W, in particular, The die 4 side surface of the sheet metal part W is not affected by the unevenness caused by the uncut peaks 12 of the contact surfaces 6a and 7a of the bunch 6 and blank holder 7, and maintains the smooth state before the press working. Indicates that the press work has been performed.

Therefore, the bread 6 and blank holder 7 manufactured by this processing method have a contact surface 6a.

Even though 7a is not polished, it can be applied without any problem to pressing not only interior parts of automobiles, but also exterior parts that require high precision and surface smoothness.

In this case, when the sheet metal part W is an inner plate part of an automobile, the height of the unevenness of the contact surface 6a of the punch 6, that is, the height h of the uncut mountain part 12, is reduced by the cutting process. 0.0 which is sufficiently smaller than the thickness (017mm)
1 to 0.04 mm, and similarly, the contact surface 7a of the blank holder 7 is also formed sufficiently smoothly by the cutting process described above, so the uncut ridges 12 of these contact surfaces 6a and 7a are polished. Even if this work is omitted and the punch 6 and blank holder 7 are used as is in the cutting process, the sheet metal part W can be pressed without any problems while maintaining the smoothness of the surface to the required level of accuracy. be.

In this embodiment, the uncut mountain portion 12 was polished by shot blasting, but the polishing process is not limited to this, and it is of course possible to use shot peening, a grindstone, etc. The above cutting process is performed using NC
This is not limited to the C machine tool 10, and may be performed by, for example, a well-known copying process.

In addition, the uncut peak portion 12 is made into a substantially trapezoidal shape by polishing in order to reduce its quality h. For example, after the aforementioned cutting is performed by the NC machine tool 10, the cutter 10a is moved to the pitch P. If the NC machine tool performs cutting at the pitch P in the same manner as described above with the position shifted by half the distance, the uncut crest 12 will be cut. 12 may be cut until its height h becomes 2% or less of the thickness of the sheet metal part W. In this case, the uncut mountain portion 12 has a trapezoidal shape with both sides protruding.

Next, a method for manufacturing the punch 6 of such a press molding apparatus by applying another example of the mold processing method of the present invention will be described with reference to FIG. FIG. 5 is an explanatory diagram for explaining the processing method.

In this manufacturing method, the manufacturing method described above is the same as shown in FIGS. 2 and 3 until the upper surface of the material mold 9 is cut using an NC machine tool 10 or the like, and after the cutting process, as shown in FIG. A punch 6 was obtained by applying a solid lubricant 15 containing molybdenum, carbon, etc. to the upper surface of the material mold 9 as shown in FIG.

More specifically, as shown in FIG. 5, the lubricant application nozzle 1
The solid lubricant 15 is injected from the lubricant application nozzle 16 to each of the cutting locations 11 while moving the solid lubricant 6 along the upper surface of the blank mold 9 at the pitch P, so that the solid lubricant 15 is filled in the cutting locations 11. Lubricant 15 was applied. At this time, by appropriately controlling the injection time etc. of the lubricant application nozzle 16, the solid lubricant 1 can be applied to the cutting area 11.
5, the height ho of the uncut peak portion 12 is 2% or less of the thickness of the sheet metal part W, i.e., 0.0, as described above.
Apply the solid lubricant 15 until the thickness is 14 mm or less,
This formed the contact surface 6a of the punch 6 including the fixed lubricant 15. In this case, the height of the unevenness of the contact surface 6a, that is, the solid lubricant 1 applied to each cutting location 11
Since the height h from 5 to the tip of the uncut crest 12 is 2% or less of the thickness of the sheet metal part W, similar to the punch described above, a highly precise and smooth contact surface 6a is obtained. .

When the sheet metal part W is press-worked using such a punch 6, the sheet metal part W can be press-worked, regardless of whether the sheet metal part W is an inner panel part or an outer panel part of an automobile, as described above. The sheet metal part W could be pressed into a desired shape while maintaining its smoothness with high precision without causing any distortion or scratches on the surface.

It goes without saying that even when the blank holder 7 is manufactured in the same manner as the punch 6, the sheet metal part W can be pressed without any problem.

Next, another example of the mold of the present invention will be described with reference to FIG. FIG. 6 is an explanatory sectional view thereof.

This mold has a chrome plated 17 as shown in the sixth figure on a relatively large curvature portion 6a+ of the contact surface 6a of the punch 6 which has been processed as shown in the fourth figure by the above-described processing method.
It has been subjected to

The large curvature portion 6a of the contact surface 6a is formed between the sheet metal part W and the sheet metal part W when the sheet metal part W is bent relatively greatly during the press working of the sheet metal part W, as shown by the imaginary line in the figure. This is the part where slipping occurs (hereinafter referred to as the slipping part),
By applying chromium plating 17 to the sliding portion 6a+ as described above, the sheet metal part W becomes more slippery (and therefore easier to bend along the contact surface 6a) during press molding of the sheet metal part W.

Therefore, similarly, the contact surfaces 6a, 7a of the punch 6, blank holder 7 and die 4.

By applying chrome plating to the sliding portion 4a, the sliding properties of the sliding portion are improved, and the sheet metal part W can be reliably formed into a predetermined shape. By improving the sliding properties of the sliding portion, its wear is reduced, and therefore,
The durability of the punch 6, blank holder 7, and die 4 is improved.

Note that the above-mentioned plating is not limited to the chromium plating 15, but even nickel plating can produce the same effect as described above.

In addition, in order to improve the sliding properties of the contact surfaces 6a, 7a, 4a of the punch 6, blank holder 7, and die 4 with respect to the sheet metal parts W as described above, it is necessary to use the solid lubricant 1 described above.
5 to each contact surface 6a, ? It may be applied to areas a and 4a.

Incidentally, in order to improve the slipperiness as described above in the punch 6 etc. processed as shown in the fifth figure, for example, before applying the solid lubricant 15 to the cutting part 11, the contact surface 6a is When the uncut mountain portion 12 of the sliding portion is polished in advance by shot blasting or the like, and the solid lubricant 15 is applied to each cutting location, the uncut mountain portion 12 of the sliding portion is absorbed into the solid lubricant 15. It is also possible to further improve the slipperiness of the sliding portion by leaving the solid lubricant 15 buried in the solid lubricant 15, or by polishing the uncut peaks 12 in the sliding portion of the contact surface 6a. .

(Effects) As is clear from the above description, according to the method for press working sheet metal parts of the present invention, after cutting the contact surface of the mold with the sheet metal part with the machine tool, the mold can be used as is. By press-forming the sheet metal parts and omitting the polishing of the contact surface of the friction mold, it is possible to significantly shorten the time from manufacturing the friction mold to pressing using the friction mold. By cutting the friction-type contact surface at a small pitch, it is possible to form a smooth surface with sufficiently small irregularities. It can be pressed into a desired shape without any problems.

According to the mold processing method of the present invention, the contact surface of the rubbing mold is cut at a small pitch using a machine tool to form a predetermined shape required for press working of sheet metal parts. It is possible to form a smooth contact surface with sufficiently small irregularities to maintain the surface smoothness of the sheet metal part during press processing using a mold, and therefore, manual polishing of the contact surface can be omitted. The processing time of the rubbing mold can be significantly shortened, and the manufacturing efficiency of the mold can be improved.

In this case, furthermore, after the cutting process, the remaining uncut peaks remaining between the cut parts of the contact surface are ground or cut into a substantially trapezoidal shape, or the solid lubricant is applied to the cut parts of the contact surface. By coating, the height of the uncut mountain part,
That is, the height of the unevenness of the contact surface can be further reduced to form a smoother contact surface, and therefore, the surface smoothness of the sheet metal part can be more reliably maintained during press processing using the mold. be able to.

Further, according to the mold for press working a sheet metal part having a thickness of 0.6 to 1.2 mm according to the present invention, the uncut mountain portion is polished or cut into a substantially trapezoidal shape, or the aforementioned By applying a solid lubricant to the cutting area, the height of the uncut peak is 2% or less of the thickness of the sheet metal part, and the contact surface is formed smoothly with high precision. Using this method, sheet metal parts can be pressed into desired shapes with high precision while maintaining surface smoothness. In this case, especially during the press working, the surface of the sheet metal part that does not come into contact with the contact surface is almost unaffected by slight irregularities on the contact surface, and the smoothness before the press work is surely improved. Therefore, even sheet metal parts such as automobile exterior parts, which require high precision surface smoothness, can be pressed without any problem.

Further, in a mold processed by the above mold processing method, when plating is applied to a portion of the contact surface where slippage occurs between the contact surface and the sheet metal component, or when a solid lubricant is applied to the contact surface. , the slipperiness of the part of the contact surface where slippage occurs between the sheet metal part and the sheet metal part is improved, and the sheet metal part can be pressed into a desired shape more reliably, and
The durability of the mold can be improved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view of a press forming method to press a sheet metal part, a method for processing a mold, and a press forming apparatus to which an example of the mold is applied according to the present invention, and FIGS. 2 to 4 are processing of the mold. FIG. 5 is an explanatory diagram for explaining another example of the mold processing method, and FIG. 6 is an explanatory sectional view of another example of the mold of the present invention. be. 6.7...Mold 10...Machine tool 12...Uncut mountain portion 17...Plating

Claims (1)

[Claims] 1. A method of press working a sheet metal part using a die, the contact surface of the die with the sheet metal part being cut into a predetermined shape by a machine tool at small pitches. A method for press working a sheet metal part, comprising a step of forming the part, and a step of pressing the sheet metal part using a mold obtained by omitting the finishing step of the contact surface after the cutting process. 2. A mold processing method for press working sheet metal parts, in which the contact surface of the mold with the sheet metal parts is cut with a machine tool at a small pitch to form a predetermined shape required for press working. A mold processing method characterized by: 3. The mold processing method according to claim 2, further comprising the step of polishing or cutting into a substantially trapezoidal shape uncut mountain portions remaining between the cut portions of the contact surface after the cutting process. 4. Claim 2, further comprising a step of applying a solid lubricant to the cut portion of the contact surface after the cutting process.
Processing method of the described mold. 5. A mold for press working a sheet metal part having a thickness of 0.6 to 1.2 mm, wherein the height of the uncut mountain portion is adjusted to the height of the sheet metal part by the mold processing method according to claim 3. A mold characterized by being polished or cut to 2% or less of the thickness of the mold. 6. A mold for press working a sheet metal part having a thickness of 0.6 to 1.2 mm, wherein the solid lubricant applied to the cutting part by the mold processing method according to claim 4 is A mold characterized in that the height of the uncut mountain portion is 2% or less of the thickness of the sheet metal part. 7. In a mold processed by the method for processing a mold according to claim 3, at least a portion of the contact surface where slippage occurs between the sheet metal part and the sheet metal part during press working is made of chromium, nickel, etc. A mold characterized by being plated with. 8. In a mold processed by the mold processing method according to claim 3, molybdenum, carbon, etc. are added to at least a portion of the contact surface where slippage occurs between the sheet metal part and the sheet metal part during press working of the sheet metal part. A mold characterized by being coated with a solid lubricant containing.