JP5314383B2 - Mold for press bending machine - Google Patents

Description

  The present invention relates to a die for a press bending machine, and in particular, it is possible to reliably perform a step bending process of various heights on a blank (metal plate) of various hardness by a simple setup operation and to generate defects such as bending flaws. It relates to molds that can be used without any problems.

  There are various types of press bending machines, such as press brakes, but the processing is basically done by setting a blank between the punch (upper die) and the die (lower die), and then the male part of the punch and the die. The female part of the mold is matched, a bending load is applied to the blank, and the blank is plastically deformed.

  Of the press bending processes, the step bending process is frequently applied to many parts of the pressed product, but the height of the step (hereinafter also referred to as the step bending height) is often different depending on the part of the product. Therefore, when the so-called V-shaped is used for the step bending process, it is necessary to replace the mold every time the step bending height is different, which is very complicated and requires a large number of molds, resulting in high cost. turn into.

  Therefore, a mounting step portion having an L-shaped cross section is formed at the tip portion of the punch and die facing each other, and the punch and die are mounted on the press bending machine and blocked on the punch and die mounting step portion. Is set to be replaceable, positioned by the rising surface of the mounting step portion, and the block is held on the mounting step portion by the magnetizing action of a mounting screw or magnet, and the tip corner surface or the block upper surface orthogonal to the block There have been proposed press bending machine dies in which a molding surface is constituted by a rising surface (Patent Document 1, Patent Document 2).

Japanese Utility Model Publication No. 55-122921 JP 2003-117607 A

  However, in the press bending machine mold described in the conventional publication, when step bending is performed on a soft blank, in order to ensure high bending accuracy, R (curvature) of the end corner surface perpendicular to the block is reduced. There was a need, but if the block is bent stepwise on a hard blank, defects such as bending scratches may occur, and it is necessary to replace it with a block with a large R, and the replacement work is still complicated. there were.

In view of such problems, the present invention is capable of performing press bending with various heights on a blank having various hardnesses reliably and without causing defects such as bending flaws by a simple set-up operation. An object is to provide a machine mold.

  Therefore, a press bending machine die according to the present invention is a punch for press bending machine in which a blank is stepped by applying a bending load by a die and a die matching operation of a male part and a female part. A mounting step portion having a male portion formed at a predetermined distance in the width direction when viewed from the center line of the step bending process and having a rising surface as a positioning portion at the tip portions facing each other of the die Is formed so as to extend in the direction of the opposite male part that is continuous with the male part, and a female block having a rectangular cross section is placed on the upper surface of the placement step part. The female block is positioned by the rising surface of the stepped portion, and the female block is formed with the mold surface constituting the female portion extending in the rising direction with respect to the mounting plane, while the female block has a rectangular cross section. The four tips of Na is characterized in that at least one corner curvature is formed so as to be different from the other three corners curvature.

  The main feature of the present invention is that the curvature of at least one of the four tip corners of the female block constituting the female part of the punch and die is made different from the curvature of the other three corners.

  For example, if at least one tip corner of the female block is formed in a large R corresponding to a hard blank and the other tip corner is formed in a small R corresponding to a soft blank, a step bending process is performed on the hard blank. When forming the molding surface with a large R corner, it is possible to reliably perform step bending without causing defects such as bending flaws, and small when bending to a soft blank. If the molding surface is constituted by the corners of the tip of R, step bending can be performed reliably with high accuracy.

  One of the features of the present invention is that a mounting step is formed continuously on the male part of the punch and die, the female block is mounted on the upper surface, and the female block is positioned by the rising surface of the mounting step. It is in the point which was made to do.

  As a result, the bending load is received at the rising surface of the mounting step portion through the female block due to the die and the male and female portions of the punch and die, so that the female block is displaced due to the bending load. There is no such thing, and a desired step bending process can be performed.

  As a result, there is no need to firmly fix the female block with bolts as in the prior art, and the female block can be held on the mounting plane with a magnet. Therefore, the female block can be exchanged and the spacer can be inserted while the mold is attached to the press bending machine, so fine adjustment to ensure the parallelism of the bending line is very easy and in a short time. It can be carried out.

  When finely adjusting the step bending height and parallelism, a spacer may be interposed between the female block and the upper surface of the mounting step portion. In addition, a spacer can also be interposed between the female block and the rising surface of the mounting step. In particular, in the present invention, since the female block is held on the upper surface of the mounting step portion by the magnet, the spacer can be inserted and removed very easily.

  The magnet may be provided on the female block side, may be provided on the upper surface side of the mounting step portion, or may be provided on both. However, if the magnet protrudes, the female block can be placed or removed. May get in the way. Therefore, it is preferable to form a recess on the back surface of the female block and / or the upper surface of the mounting step portion, and fit the magnet flush with the recess.

  The female block and the spacer may be made of any material that does not impair the magnetic adhesion force of the female block by the magnet.

  Hereinafter, the present invention will be described in detail based on specific examples. 1 to 4 show a preferred embodiment of a press bending machine mold according to the present invention. In the figure, the mold is composed of a combination of a punch 10 and a die 20. In the punch 10, the main body 12 has a substantially side-inverted triangular shape, and an upper end portion of the main body 12 is integrally formed with a mounting portion 11 for a press bending machine (not shown), and the mounting portion 11 has a substantially constant thickness. It has a solid shape that is continuous in the length direction.

  On the other hand, the main body 22 of the die 20 has a substantially inverted triangular side surface, and a mounting recess 21 to a press bending machine (not shown) is integrally formed on the bottom surface, and the mounting recess 21 has a substantially constant depth. It has a continuous shape in the length direction.

  In addition, male portions 13 and 23 having a substantially right angle are formed at opposite end portions of the punch 10 and the main bodies 12 and 22 of the die 20 with a predetermined distance in the width direction when viewed from the center line a of the step bending process. And formed continuously in the longitudinal direction.

  Further, a mounting step portion 14 having an L-shaped cross section is continuous with one mold surface of the male mold portions 13 and 23 at the opposed tip portions of the punch 10 and the main bodies 12 and 22 of the die 20 and the mold surface. The rising surfaces 15 and 25 at the end of the mounting steps 14 and 24 are formed in the same direction, and the vertical surfaces of the mounting steps 14 and 24 are perpendicular to the mounting steps 14 and 24. Are formed so as to be parallel to each other.

  Circular recesses 17 and 27 are formed in the center of the upper surfaces of the mounting steps 14 and 24, and disk-shaped magnets 18 and 28 are fitted and fixed to the circular recesses 17 and 27, respectively. Yes.

  In addition, female blocks 16 and 26 are placed on the upper surfaces of the placing steps 14 and 24 and are magnetically attached and held by the magnets 18 and 28. The rear end surfaces of the female blocks 16 and 26 are positioned by contacting the rising surfaces 15 and 15 of the mounting steps 14 and 24.

  The female blocks 15 and 25 are manufactured to have a rectangular cross section, and of the four tip corners, two are formed at the same 0.2R, the other one is formed at 0.4R, and the other is formed at 0.6R. The mold surfaces 19 and 29 constituting the female mold portion can be selected depending on which surface of the female blocks 15 and 25 is placed on the upper surfaces of the placement steps 14 and 24. The mold surfaces 15 and 25 extend in a direction perpendicular to the upper surfaces of the mounting steps 14 and 24.

  When the blank W is step-bended, the blank W is set between the punch 10 and the die 20, the punch 10 is lowered, and the opposing male and female mold parts are subjected to mold matching operation to apply a bending load to the blank W. The step portion is bent into the blank W.

  At that time, the bending load accompanying the lowering of the male mold portions 13 and 23 is transmitted to the rising surfaces 15 and 25 of the mounting step portions 14 and 24 through the female blocks 16 and 26 and is received by the rising surfaces 15 and 25. The female blocks 16, 26 are not displaced and a predetermined step bending process can be performed.

  When step bending is performed by the method shown in FIG. 3 (a), the step bending height is determined by the width L of the female blocks 16, 26, so the step bending height is changed. In this case, as shown in FIG. 4, the female blocks 16 and 26 having a width L are prepared, and the prepared female blocks 16 and 26 are attached to the press bending machine while the punches 10 and the main bodies 12 and 22 of the die 20 are attached. Replace with mold blocks 16, 26.

  Further, when finely adjusting the step bending height or ensuring the parallelism of the bend line, the spacer 30 may be placed on the upper surfaces of the female blocks 16 and 26 and the mounting step surfaces 14 and 24 and / or as needed. It inserts between the surfaces 15 and 25 and performs.

  Further, instead of the method shown in FIG. 3 (a), the blank W can be step-bent by the method shown in FIG. 3 (b).

  By the way, when the blank W having different hardness is subjected to step bending, there is a concern about defects such as bending flaws. Therefore, when bending the soft blank W, the female blocks 16 and 26 are placed on the upper surfaces of the placement steps 14 and 24 so that the surfaces continuous to the 0.2R tip corners become the mold surfaces 19 and 29, respectively. . As a result, the soft blank W can be step bent with high accuracy.

  When step bending a hard blank W, the female blocks 16 and 26 are placed on the top surfaces of the mounting step portions 14 and 24 so that the surfaces continuous with the 0.4R or 0.6R tip corners become the mold surfaces 19 and 29, respectively. Placed on. As a result, the hard blank W can be surely subjected to step bending without causing defects such as bending flaws.

It is a principal part expanded sectional view which shows preferable embodiment of the metal mold | die for press bending machines which concerns on this invention. It is a schematic perspective view which shows the said embodiment. It is a cross-sectional side view which shows typically the system of two step bending processes in the said embodiment. It is a figure which shows typically the operation | work which changes the height of the step bending of the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Punch 13 Male part 14 Mounting step part 15 Standing surface 16 Female block 17 Recess 18 Magnet 19 Mold surface 20 Die 23 Male part 24 Mounting step part 25 Standing surface 26 Female block 27 Recess 28 Magnet 29 Mold surface 30 Spacer W Blank

Claims (3)

In a die for a press bending machine, in which a blank is stepped by applying a bending load by a die and a die part matching operation of a punch and a die,
A male part is formed at a front end of the punch (10) and the die (20) facing each other with a predetermined distance in the width direction when viewed from the center line (a) of the step bending process, and rises. A mounting step portion (14, 24) having the surface (15, 25) as a positioning portion is formed to extend in the direction of the opposite male portion that is continuous with and opposite to the male portion,
A female block (16, 26) having a rectangular cross section is placed on the upper surface of the placement step (14, 24), and a rising surface (15, 25) of the placement step (14, 24). ), The female block (16, 26) is formed so that the mold surface constituting the female mold portion extends in a direction to rise with respect to the upper surface of the mounting step (14, 24),
A recess (17, 27) is formed on the back surface of the female block (16, 26) and / or the upper surface of the mounting step (14, 24), and a magnet is formed in the recess (17, 27). (18,28) are fitted flush and the female block (16,26) is held interchangeably,
To bend without bending a blank with a hard curvature at two corners located at both ends of one long side of the rectangular cross section of the four corners of the rectangular shape of the female block (16, 26). Compared to the curvatures of the two corners of one long side equal to each other, in order to bend a soft blank with high precision, the curvature of the two corners located at both ends of the other long side is different from each other with a small curvature And a mold for a press bending machine, which is formed to have a large curvature.   The step bending height can be finely adjusted by providing a spacer (30) between the female block (16, 26) and the upper surface of the mounting step (14, 24). Mold for press bending machine.   A spacer (30) is interposed between the female block (16, 26) and the rising surface (15, 25) of the mounting step (14, 24) so that the female block (14, 24) The die for a press bending machine according to claim 1, wherein the advance / retreat position can be finely adjusted.

Images