JP2007289968A - Press die set, method for forming stepped portion, and pressed product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a press die set, which press die set can decrease the generation of warping in flat planes continued to the front part and the rear part of stepped portions of a plate in forming the stepped portion on the plate, and further to provide a method for forming the stepped portion utilizing the same press die set, and further to provide a pressed product formed by the same method for forming the stepped portion. <P>SOLUTION: The press die set 1 comprises an upper die 2 having upper die projected portion 2a, and a lower die 3 having a lower die projected portion 3a. The clearance S between the upper die projected portion 2a and the lower die projected portion 3a is within a range from 70 to 120% of the thickness t of a metal plate 10 before press work. The stepped portion 11 is formed on the flat planes of the metal plate 10 by pressing the metal plate 10 utilizing the press die set 1. The pressed product has the stepped portion 11 of the metal plate 10, wherein the thickness of stepped portion is within a range from 70 to 100% of the thickness t of the metal plate 10 before press work. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a press die, a step processing method using the press die, and a pressed product formed by the step processing method.

  In a press-processed product in which a step is formed on a part of a plate material, the step is sometimes processed by half-cut processing (see, for example, Patent Document 1).

  As shown in FIG. 5, such a half-cut process is performed by setting the press die 101 so as to eliminate the clearance between the side surface of the convex portion 120 of the upper mold 102 and the side surface 130 of the convex portion of the lower mold 103. A step 111 is formed by applying a pressing force to the metal plate 110, which is a processed material, by the press die 101 to cause the metal plate 110 to undergo shear deformation.

JP-A-9-129208

  However, the conventional half-cut processing has a problem in that a large warp is generated in the flat portions 112 and 112 before and after the step in the processed metal plate 10 (pressed product). In particular, for a workpiece having a thin member thickness (for example, 0.5 mm or less), it is difficult to control the warp because the thinner the member thickness is, the easier the deformation occurs, with respect to the difference in strain. Further, a press-processed product having a large ratio of the outer dimension to the member thickness tends to amplify the generated distortion and tends to be difficult to control warpage.

  The present invention has been made to solve the above-described problems, and in the case where a step is formed on a plate material, a press metal that can reduce the occurrence of warpage in a flat portion before and after the step. It is an object of the present invention to propose a mold, a step processing method using this press die, and a press-worked product formed by this step processing method.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a press die for performing step processing on a flat portion of a workpiece, and is formed along a designed flat shape of the step. An upper mold having a convex part and a lower mold having a convex part formed along the planar shape of the step, and the clearance between the convex part of the upper mold and the convex part of the lower mold is It is characterized by being in the range of 70% or more and 120% or less of the member thickness before processing the workpiece.

  The invention described in claim 2 is the press die according to claim 1, characterized in that the clearance is a member thickness before processing the workpiece.

  According to such a press die, it is possible to reduce the occurrence of warpage in the flat portions before and after the step as the step is processed on the workpiece, thereby enabling high-quality press processing. Here, if the clearance between the upper convex portion and the lower convex portion is less than 70%, there is a large possibility that a warp larger than the same thickness as that required for precision parts will occur. Become. On the other hand, if the clearance is larger than 120%, the spring back after processing is large, and it becomes difficult to obtain a predetermined step size. In addition, the height of the preferable level | step difference shape | molded by the said press metal mold | die is below the member thickness before the process of a workpiece, More preferably, it is 1/3-2/3 with respect to the member thickness before the process of a workpiece. Is within the range.

  According to a third aspect of the present invention, there is provided an upper mold having a convex portion formed along the designed planar shape of the step, and a lower mold having a convex portion formed along the planar shape of the step. A step processing method for forming the step on a flat portion of the workpiece by applying a pressing force, wherein the thickness of the step portion of the workpiece is the thickness of the workpiece before processing the workpiece. It is characterized in that it is molded so as to be in the range of 70% to 100%.

  According to such a step processing method, the warp of the flat portion continuous to the step formed by press working is reduced as compared with the conventional method, and the flatness is well formed. Here, when the member thickness of the step portion is smaller than 70%, there is a high possibility that a warp larger than the same thickness as the plate thickness required as a precision component is generated. In addition, the preferable height of the level | step difference shape | molded by the said level | step difference processing method is below the member thickness before processing of a workpiece, More preferably, it is 1/3-2/3 with respect to the member thickness before processing of a workpiece. Within range.

  The invention according to claim 4 is a press-processed product in which a step portion is formed on a flat portion of a workpiece, and a member thickness of the step portion is 70% of a member thickness before processing of the workpiece. It is characterized by being in the range of 100% or less. Here, if the member thickness of the stepped portion of the press-processed product is smaller than 70%, there is a high possibility that a warp larger than the plate thickness as required as a precision part will occur.

  The invention according to claim 5 is the press-worked product according to claim 4, wherein the maximum dimension is in a range of 25 times to 700 times the thickness of the workpiece before processing. It is characterized by that. It should be noted that if the maximum dimension of the pressed product is smaller than 25 times the thickness of the material before processing the workpiece, there is sufficient rigidity to suppress deformation against the strain generated by the pressing, and therefore according to the present invention. It is possible to obtain the required accuracy regardless of whether it is a pressed product. On the other hand, if it is larger than 700 times, it is difficult to suppress warping as required for precision parts.

  Furthermore, the invention according to claim 6 is the press-worked product according to claim 4 or claim 5, wherein a member thickness of the workpiece before processing is 0.5 mm or less. Yes.

  Such a press-formed product is formed in a flat portion with a high-quality step according to the plate thickness of the work material, the shape dimension of the press work product with respect to the plate thickness of the work material, the step shape, etc. This is preferable because warpage and deformation are reduced. In addition, the height of the preferable level | step difference in the said press-work product is below the member thickness before processing of a workpiece, More preferably, it exists in the range of 1/3-2/3 with respect to the member thickness before processing of a workpiece. It is.

  According to the press die of the present invention and the step processing method using this press die, in the case of forming a step in the plate material, it becomes possible to reduce the occurrence of warpage in the flat part before and after the step, It becomes possible to provide high-quality pressed products.

The best mode for carrying out the present invention will be described in detail with reference to the drawings. In the present embodiment, a case where a part of a cartridge that stores a magnetic medium, more specifically, a shutter member of the cartridge is molded as a press-processed product will be described.
In the drawings to be referred to, FIG. 1A is a cross-sectional view showing a press die according to the present embodiment, and FIG. 1B is an enlarged view showing a part of FIG. 2A and 2B are diagrams showing a press-processed product according to this embodiment, where FIG. 2A is a perspective view, and FIG. 2B is an enlarged cross-sectional view. FIG. 3 is a diagram showing the relationship between the clearance between the convex portions of the upper die and the lower die and the warpage of the pressed product, where (a) has no clearance, and (b) has the same clearance as the member thickness. Each case is shown. FIG. 4A is a plan view showing the measurement direction of warpage in the demonstration experiment, FIG. 4B is a schematic view showing the method of measuring warpage, and FIG. 4C is an explanatory view showing the direction of warpage.

  A press die 1 according to the present embodiment is a press die 1 for applying a step process to a flat portion of a metal plate 10 that is a workpiece, and is designed as shown in FIG. An upper mold 2 having an upper mold convex portion (convex portion) 2a formed along the planar shape of the step and a lower mold having a lower mold convex portion (convex portion) 3a formed along the planar shape of the step. 3 is provided.

  In this embodiment, by applying a pressing force to the metal plate 10 by the press die 1, as shown in FIGS. 2 (a) and 2 (b), the flat portion 12 of the metal plate 10 (pressed product 15) is applied. Then, the step 11 is formed along the circumferential direction, and the pressed product 15 is formed. And the quality of the plane parts 12 and 12 which continue to the level | step difference 11 is ensured so that curvature may not arise with a level | step difference process (it is reduced). In addition, according to the press die 1 and the level | step difference processing method which concern on this embodiment, when the plate | board thickness t of the metal plate 10 is thin, it exists in the tendency for the effect which reduces curvature to become larger. In particular, the plate thickness t is effective when it is 0.5 mm or less, preferably 0.3 mm or less, more preferably 0.25 mm or less (see FIG. 1B). In the drawing, reference numeral 13 denotes a boss formed by burring the center of the metal plate 10. Reference numeral 14 denotes an edge wall formed by drawing the peripheral edge of the metal plate 10.

  As shown in FIG. 1B, the press die 1 has a clearance S between the side surface of the upper mold convex portion 2 a of the upper mold 2 and the side surface of the lower mold convex portion 3 a of the lower mold 3. It is configured to have the same width as the previous member thickness t. The clearance S is not limited as long as it is within the range of 70% to 120%, and preferably 80% to 100%. Moreover, the material which comprises the press metal mold | die 1 (upper mold | type 2 and lower mold | type 3) is not limited, It is suitably from the well-known material which has the intensity | strength which does not deform | transform by the press work of the metal plate 10. Select and use.

  As shown in FIG. 1A, the upper mold 2 is formed with an upper mold convex portion 2 a according to the outer diameter of the step 11 of the press-processed product 15. In the present embodiment, the height of the upper mold convex portion 2a is formed to be 1/3 to 2/3 of the member thickness t before the metal plate 10 is processed. The upper mold convex portion 2 a is formed on the outer periphery of the concave portion 2 b by forming a substantially circular concave portion 2 b in the central portion of the upper mold 2 in accordance with the shape of the step 11. Needless to say, the shape of the upper mold convex portion 2a is not limited, and is appropriately set according to the shape of the step 11 of the designed press-worked product 15.

  As shown in FIG. 1A, the lower mold 3 is formed with a lower mold convex portion 3 a according to the inner diameter of the step 11 of the press-processed product 15. In the present embodiment, the lower mold convex portion 3 a is formed so that the height thereof is 1/3 to 2/3 of the member thickness t before the metal plate 10 is processed. As shown in FIG. 1B, the lower mold convex portion 3a can be inserted into the inner space of the upper mold convex portion 2a with a predetermined clearance S secured between the lower mold convex portion 2a and the upper mold convex portion 2a. It is formed into a shape.

  In addition, the lower mold | type 3 which concerns on this embodiment is formed in the substantially circular column shape by planar view. The diameter of the lower mold 3 is formed according to the shape of the metal plate 10. In this embodiment, as shown in FIG. 1A, the edge wall 14 formed on the periphery of the metal plate 10 in the previous step. It is formed in the outer diameter along the inner surface. In addition, a substantially circular boss hole 3b is formed in the approximate center of the lower mold 3, and the boss 13 formed on the metal plate 10 in the previous process is configured not to be deformed during the step processing. Yes. Here, the boss hole 3b of the lower mold 3 is formed as necessary, and is not necessarily formed. Further, the shape of the lower die 3 is not limited to a circular shape in plan view, and may be formed according to the shape of the press-worked product 15 that is appropriately designed, such as a rectangle, an ellipse, and other polygons.

  In the present embodiment, the upper die 2 is lowered from above the metal plate 10 so that the metal plate 10 is stepped, but it goes without saying that the lower die 3 may be raised from below. In addition, the pressing direction to the metal plate 10 is not limited.

  Moreover, although the upper mold | type convex part 2a or the lower mold | type convex part 3a shall be integrally formed about the upper mold | type 2 and the lower mold | type 3, respectively, The structure of the press metal mold | die 1 is not limited to this. For example, by forming the upper mold convex portion 2a from a separate member, the upper mold convex portion 2a is processed with respect to the metal plate 10 held between the upper mold 2 and the lower mold 3, thereby forming a step. It is good also as a structure which processes.

Next, the step machining method according to the present embodiment will be described.
In this embodiment, as shown in FIGS. 2A and 2B, the metal plate 10 (press-processed product 15) is substantially circular, and the height h 1 is 1 / th of the member thickness t before the metal plate 10 is processed. The case where the step 11 of 3 to 2/3 is formed will be described. In addition, the shape of the level | step difference 11 is not limited to circular, According to the intended purpose of the press work product 15, it can be shape | molded suitably in arbitrary shapes.
Moreover, in this embodiment, the maximum dimension of the projection shape seen from the press pressing direction of the press-processed product 15 is within a range of 25 to 700 times the plate thickness t before processing of the metal plate 10, preferably 50. However, the shape of the pressed product 15 is not limited to the above.

  The step processing according to the present embodiment includes a placement step of placing the metal plate 10 on the lower mold 3 and a pressing step of forming the step 11 by applying a pressing force to the metal plate 10 from above with the upper die 2. Become.

<Arrangement process>
The arranging step is a step of arranging the metal plate 10 on which the boss 13 and the edge wall 14 are formed on the surface of the lower mold 3. At this time, the metal plate 10 is arranged so that the boss 13 is inserted into the boss hole 3 b formed in the center of the lower mold 3, and the side wall 14 extends along the outer periphery of the lower mold 3.

  In the placement step, the upper die 2 is placed at a raised position, and a gap is formed between the upper die 2 and the lower die 3 so that the metal plate 10 can be moved.

<Pressing process>
The pressing step is a step of performing step processing by processing the upper die 2 from above the metal plate 10 arranged on the upper surface of the lower die 2 by the arranging step and applying a pressing force. At this time, the upper mold 2 and the lower mold 3 are formed so that the upper mold convex part 2a and the lower mold convex part 3a are fitted to each other with a clearance S, respectively. A step 11 is formed on the flat portion 12 of the metal plate 10 by the step of the lower mold 3.

  In the present embodiment, since the metal plate 10 is disposed in a state where the boss 13 and the edge wall 14 that are pre-formed on the metal plate 10 are engaged with the boss hole 3b and the peripheral edge of the lower mold 3, respectively, The metal plate 10 does not move and can be processed with high accuracy. Needless to say, a member for fixing the metal plate 10 may be provided separately or formed on the press die 1.

  In the pressed product formed by the step processing method, the member thickness t1 of the step 11 is in the range of 70% to 100%, preferably in the range of 80% to 95% of the plate thickness t before processing of the metal plate 10. Formed inside. The member thickness t <b> 1 is measured by an optical measurement microscope or a non-contact dimensional measuring device in the substantially normal direction of the step shape portion.

  According to the press die according to the present embodiment and the step machining method using this press die, a clearance equivalent to the member thickness t of the metal plate 10 is provided between the upper mold convex portion 2a and the lower mold convex portion 3a. Since S is secured, it is possible to reduce the load on the metal plate 10 during press processing and reduce the occurrence of distortion in the metal plate 10 as compared with the conventional half-cut processing in which the metal plate 10 is punched out. It becomes. For this reason, the curvature which arises in the plane part 12 which continues to the level | step difference 11 of the shape | molded press work goods 15 is reduced, and it becomes possible to provide a high quality press work goods. Therefore, for example, with respect to the step processing of precision parts, such as a shutter of a recording disk cartridge, if the flat surface portion 12 is warped, the opening / closing movement is hindered and the required function cannot be exhibited. It is possible to apply.

  Further, in the press die 1, the clearance S between the upper die 2 and the lower die 3 is configured to be substantially the same as the plate thickness t of the metal plate 10, so that the shape of the step 11 after processing is uniformly formed. The

As mentioned above, although preferred embodiment was described about this invention, this invention is not limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the meaning of this invention.
For example, in the above embodiment, the thickness of the metal plate is 0.5 mm or less, but the member thickness of the workpiece that can be processed by the press die and the burring method according to the present invention is not limited. It may be set appropriately.

  Further, the material of the workpiece is not limited. For example, the same effect can be obtained by using any of stainless steel SUS304-SP, aluminum (Al), and stainless steel SUS304-CSP. .

Moreover, it cannot be overemphasized that the press metal mold | die of this invention may be used as an individual metal mold | die, and may be used as a part of progressive metal mold | die.
Further, in the above-described embodiment, the case where the press-processed product is formed in a substantially circular shape has been described, but it goes without saying that the press-processed product is not limited to a circular shape, for example, an ellipse, a rectangle, and other It may be a polygon or the like.

  Furthermore, in the above-described embodiment, the case where the part of the cartridge that stores the magnetic medium, more specifically, the case where the shutter member of the cartridge is formed as the press-processed product has been described. However, the press mold and the step processing method of the present invention Needless to say, the usage, shape, etc. of the pressed product are not limited.

  Hereinafter, the results of a demonstration experiment for improving the quality of a pressed product by the press die and the step processing method according to the present invention will be described.

  In this demonstration experiment, a press mold (conventional press mold) in which the clearance S is 0 mm between the upper mold convex portion 2a and the lower mold convex portion 3a, and the clearance S is the member thickness t of the metal plate 10 are used. With the press die 1 (the press die according to the present invention) configured as described above, the flat plate 12 of the press-work product 15 (metal plate 10) before and after the step processing is performed on the metal plate 10, respectively. By measuring the amount of warpage, the quality improvement effect (reduction of warpage of the flat surface portion) by the step processing method using the press die 1 according to the present invention was verified.

  In this demonstration experiment, a metal plate 10 (stainless steel SUS304-SP) having a member thickness of 0.15 mm is used. And about the plane part 12 of the press-processed goods 15 (metal plate 10) before and behind level | step difference process, the change of the curvature of A, B, C of 3 directions shown to Fig.4 (a) was measured, and the comparison was performed. In this demonstration experiment, the press work product 15 was molded so that the height of the step was ½ (0.075 mm) of the member thickness t before the metal plate 10 was processed.

  As shown in FIG. 4B, the warpage is measured by measuring the coordinates of three points (a, b, c) at the base of the boss 13 with a laser displacement meter L to form a virtual plane Z. Then, by measuring the displacement of the plane portion 12 while moving the laser displacement meter L in the A direction, B direction, and C direction of the metal plate 10 on which the boss 13 is formed, the coordinates of the three points a, b, and c are used. The warpage of the flat surface portion 12 with respect to the formed virtual surface Z is measured. Here, as shown in FIG. 4C, the warpage +-is defined as + for the warpage to the opposite side of the protruding portion of the boss 13 and-for warpage to the boss 13 side.

  As shown in FIG. 3A, when the clearance S is 0 as in the conventional step processing method (half-cut processing), all three directions A, B, and C warp by about 300 mm. Increased results. On the other hand, when the clearance S is the member thickness t (0.15 mm), as shown in FIG. 3B, the change in warpage is 200 mm or less even in the largest direction (A direction). Therefore, compared with the conventional step processing method by half-cut processing in which the clearance S is zero, according to the step processing method of the present invention in which the clearance S is secured about the member thickness t of the workpiece, the warp generated in the flat surface portion 12 is achieved. The result was greatly reduced.

  In addition, the same tendency was shown as a result of having performed the same test about the board | plate material made from aluminum (Al), and stainless steel (SUS304-CSP) as the metal plate 10. As shown in FIG.

(A) is a cross-sectional view which shows the press die concerning this embodiment, (b) is an enlarged view which shows a part of (a). It is a figure which shows the press work goods which concern on this embodiment, Comprising: (a) A perspective view, (b) is an expanded sectional view. It is a figure which shows the relationship between a clearance and the curvature of a press-work product, (a) shows the case where there is no clearance, (b) shows the case where it has the same clearance as member thickness, respectively. (A) is a top view which shows the measurement direction of the curvature in verification experiment, (b) is the schematic which shows the measuring method of curvature, (c) is explanatory drawing which shows the direction of curvature. It is sectional drawing which shows the conventional press metal mold | die.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Press die 2 Upper mold 2a Upper mold convex part 3 Lower mold 3a Lower mold convex part 10 Metal plate (working material)
11 Step 12 Flat part 15 Press work S Clearance t Member thickness

Claims (6)

A press die for applying a step process to a planar portion of a workpiece,
An upper mold having a convex portion formed along the planar shape of the designed step;
A lower mold having a convex portion formed along the planar shape of the step,
A press die, wherein a clearance between the convex portion of the upper mold and the convex portion of the lower mold is in a range of 70% or more and 120% or less of a member thickness before the workpiece is processed.   2. The press die according to claim 1, wherein the clearance is a member thickness before the workpiece is processed. An upper mold having a convex portion formed along the planar shape of the designed step;
A step processing method of forming the step on the flat portion of the workpiece by applying a pressing force with a lower mold having a convex portion formed along the planar shape of the step,
A step processing method, wherein the step thickness portion of the workpiece is shaped so that the member thickness is in a range of 70% to 100% of the thickness of the workpiece before the workpiece is processed. It is a press-processed product in which a stepped portion is formed on the flat portion of the workpiece,
The press-processed product, wherein a member thickness of the stepped portion is in a range of 70% to 100% of a member thickness before processing of the workpiece.   5. The press-worked product according to claim 4, wherein a maximum dimension is in a range of 25 to 700 times a thickness of a member before the workpiece is processed.   The pressed product according to claim 4 or 5, wherein a member thickness of the workpiece before processing is 0.5 mm or less.

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