JP6651057B1 - Press forming apparatus and manufacturing method - Google Patents

Abstract

The press forming apparatus may be a press forming apparatus that presses and forms a heated work while cooling it. The press forming apparatus may include a first mold that supports the work. The press forming apparatus may include a second mold that is arranged to face the first mold. The first mold may include a punch having a first forming surface for forming a workpiece. The first mold may include a blank holder movably disposed along a side surface extending from the first forming surface of the punch and having a support surface that supports an end of the workpiece. The second mold may have a die portion facing the first molding surface and having a second molding surface for molding a workpiece. The second mold may have a trim part integrally formed with the die part. The trim part may have a blade part for cutting an end of the work. The die portion may have a flow passage for flowing a coolant for cooling the work along the second forming surface.

Description

  The present invention relates to a press forming apparatus and a manufacturing method.

Non-Patent Document 1 discloses a manufacturing method in which a heated work is pressed and formed while being cooled, and then a trim die is lowered to cut an end of the work. According to the above-mentioned manufacturing method, it is necessary to provide a hydraulic tanker and a reaction force generator such as a hydraulic generator for controlling the hydraulic tanker in the mold so that the trim die does not move ahead of the pad during molding. Patent Literature 1 describes that a trimming die and a blank holder are provided with a regulating portion that regulates a posture of a work so that the work does not contact a punch side cutting edge and a die side cutting blade during press forming before trimming. ing.
Non-Patent Document 1 “Press Technology August 2014”, Vol. 52, No. 8, pp. 22-23 “[Special Issue] Latest Trend of Hot Stamping Technology in Full-scale Development of Trim Manufacturing Method in Hot Stamping (Hot Stamping) Type”, Daily Kogyo Shimbun Patent Document 1 Patent No. 6256571

Issues to be solved

  When performing press forming such as hot stamping (also referred to as hot press forming or PHS), a forming die may be provided with a flow passage through which a coolant for cooling a work flows. However, depending on the shape of the work, it may be difficult to provide a flow passage in the forming die.

General disclosure

  The press forming apparatus according to one embodiment of the present invention may be a press forming apparatus that presses and forms a heated work while cooling it. The press forming apparatus may include a first mold that supports the work. The press forming apparatus may include a second mold that is arranged to face the first mold. The first mold may include a punch having a first forming surface for forming a workpiece. The second mold may have a die portion facing the first forming surface and having a second forming surface for forming a workpiece. The second mold may have a trim part integrally formed with the die part. The trim part may have a blade part for cutting the end of the work. The die portion may have a flow passage for flowing a coolant for cooling the work along the second forming surface.

  The first mold may include a blank holder movably disposed along a side surface extending from the first forming surface of the punch and having a support surface that supports an end of the workpiece.

  The trim portion may be integrally formed with the die portion by extending from the second molding surface and being fixed to a fixing surface of the die portion facing the blank holder.

  The trim part may be detachably fixed to the fixing surface of the die part.

  The trim portion may have a holding surface facing the support surface and holding the end of the work between the trim surface and the support surface, and the trim portion may have a protrusion that projects from the blade portion toward the blank holder.

  The second forming surface may include a step for bending the work to form the flange. The blade portion may be provided inside a tangent line that contacts the corner portion of the protrusion and the step portion.

  With the end of the work held between the support surface of the blank holder and the holding surface of the protrusion, the die and the trim are moved toward the first mold, and the blank holder is moved along the side of the punch. By moving, the work is pressed and formed by the first forming surface and the second forming surface, and before the die and the trim reach the bottom dead center, the blade cuts the end of the work. Good.

  The manufacturing method according to one embodiment of the present invention may be a manufacturing method of manufacturing a press-formed product by pressing and shaping a heated work while cooling it between a first mold and a second mold. The first mold may include a punch having a first forming surface for forming a workpiece. The first mold may include a blank holder movably disposed along a side surface extending from the first forming surface of the punch and having a support surface that supports an end of the workpiece. The second mold may include a die portion facing the first forming surface and having a second forming surface for forming a workpiece. The second mold may include a trim portion integrally formed with the die portion. The trim part may have a blade part for cutting the end of the work. The die portion may have a flow passage for flowing a coolant for cooling the work along the second forming surface. In the manufacturing method, the die and the trim are moved toward the first mold while the end of the work is held between the blank holder and the trim, and the blank holder is moved along the side surface of the punch. The method includes a step of pressing and forming the work by the first forming surface and the second forming surface, and cutting the end of the work by the blade before the die and the trim reach the bottom dead center. May be.

  The above summary of the present invention does not list all of the necessary features of the present invention. Further, a sub-combination of these feature groups can also be an invention.

It is a figure for explaining an example of a hot stamp type inside trim manufacturing method. It is a figure for explaining an example of a hot stamp type inside trim manufacturing method. It is a figure for explaining an example of a hot stamp type inside trim manufacturing method. It is a figure for explaining an example of a hot stamp type inside trim manufacturing method. It is an enlarged view of the part which forms the flange part of the work of a pad. It is a figure for explaining the press molding device concerning this embodiment. It is a figure for explaining the press molding device concerning this embodiment. It is a figure for explaining the press molding device concerning this embodiment. FIG. 3 is an enlarged view of a part of a die portion near a trim portion and a trim portion.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all combinations of the features described in the embodiments are necessarily essential to the solution of the invention.

  In hot stamp molding (also referred to as hot press molding or PHS), it is conceivable to cut after a press molded product has been cooled to have a strength equivalent to 1500 MPa. However, the strength (hardness) and residual stress of the cut portion of the press-formed product cut after cooling are high, and delayed fracture may occur. In order to prevent such delayed fracture, it is conceivable to cut a workpiece in a high temperature state before cooling. As a result, the strength (hardness) and residual stress of the press-formed product are reduced, and the possibility of delayed fracture can be reduced.

  FIGS. 1A, 1B, 1C, and 1D are diagrams for explaining an example of a hot stamp type trim manufacturing method for cutting a work in a high temperature state before being cooled. According to this manufacturing method, the heated work is pressed and molded while being cooled, and then the trim die is lowered to cut the end of the work.

  The press forming apparatus includes an upper die 10 and a lower die 30. The work 50 is arranged between the upper mold 10 and the lower mold 30. The upper mold 10 has a die holder 12, a trim die 14, a pad 16, and a reaction force generator 20 such as a hydraulic tanker. The pad 16 is disposed along the molding surface 16a, and has a flow passage 19 through which a coolant such as water for cooling the work 50 flows. The lower die 30 has a punch holder 32, a punch 34, a blank holder 36, and a reaction force generator 38 such as a spring. The punch 34 has a flow passage 39 through which a coolant such as water for cooling the work 50 flows along the forming surface 34a.

  The trim die 14 is fixed to the die holder 12. The pad 16 is connected to the reaction force generator 20 so as to be movable in a direction approaching and away from the die holder 12. The die holder 12 holds the reaction force generator 20.

  The punch 34 is fixed to the punch holder 32. The blank holder 36 is connected to the punch holder 32 via a reaction force generator 38 so as to be movable in a direction toward and away from the punch holder 32.

  As shown in FIG. 1B, the end 52 of the heated work 50 is held between the holding surface 14 a of the trim die 14 and the support surface 36 a of the blank holder 36. In this state, the die holder 12 receives the pressing pressure 11 and moves to the lower mold 30 side. At this time, the pad 16 receives the oil pressure 17 from the reaction force generator 20 and moves to the lower die 30 side together with the trim die 14. Thus, the work 50 is pressed and formed on the forming surface 16 a of the pad 16 and the forming surface 34 a of the punch 34.

  As shown in FIG. 1C, when the pad 16 moves to the bottom dead center, the hydraulic stroke received by the pad 16 is adjusted, and the pad 16 remains at the bottom dead center. The die holder 12 further receives the press pressure 11 and moves to the lower die 30 side. At this time, only the trim die 14 moves with respect to the punch 34. Thereby, the end 52 of the work 50 is cut by the corner blade 14 b of the trim die 14.

  According to the above-described manufacturing method, it is necessary to control the movement of the pad 16 by the oil pressure of the reaction force generator 20 so that the trim die 14 does not move ahead of the pad 16 during the press forming. However, installing the reaction force generator 20 may increase the cost. In addition, the provision of the reaction force generating device 20 may increase the size of the mold.

  FIG. 2 is an enlarged view of a portion surrounded by reference numeral 60 in FIG. 1C. In some press-formed products, the width w of the flange portion 54 of the work 50 is much shorter than the depth h of the deep drawing, and it may be difficult to secure the strength of the pad 16. Moreover, the pad 16 has a flow passage 19 through which a coolant such as water for cooling the work 50 flows. By forming the flow passage 19 inside the pad 16, the thickness 16c of the pad 16 is further reduced. Therefore, if the width of the flange portion of the press-formed product is narrow, it may be more difficult to arrange and process the flow passage 19 of the pad 16 while securing the strength of the pad 16.

  Therefore, the press forming apparatus according to the present embodiment performs trimming in a hot stamp forming process without using a hydraulic tanker. In addition, it is possible to arrange a flow passage in the pad while ensuring the strength of the pad regardless of the shape of the work.

  With reference to FIG. 3A, FIG. 3B, FIG. 3C, and FIG. 4, the press forming apparatus according to the present embodiment will be described.

  The hot press forming apparatus manufactures a press-formed product by pressing and forming the heated work 500 while cooling it. The hot press molding apparatus includes an upper mold 100 and a lower mold 200 as molds. The upper mold 100 is an example of a second mold. The lower mold 200 is an example of a first mold. The upper mold 100 may function as a first mold, and the lower mold 200 may function as a second mold. The lower mold 200 supports the work 500. The upper mold 100 is arranged to face the lower mold 200. The work 500 may be a plate material. The blank 500 may be a plate made of a metal material such as hard steel, mild steel, aluminum, titanium or copper.

  The lower mold 200 has a punch holder 202, a punch 204, a blank holder 206, and a reaction force generator 208 such as a spring. The punch 204 has a molding surface 204a for molding the work 500, facing the upper mold 100. The molding surface 204a is an example of a first molding surface. The blank holder 206 is movably disposed along a side surface 204b extending from the forming surface 204a of the punch 204 toward the punch holder 202, and has a support surface 206a that supports the end portion 502 of the work 500. The punch 204 is disposed along the molding surface 204a, and has a flow passage 209 through which a coolant for cooling the work 500 flows.

  The upper die 100 has a die holder 102, a die part 104, a movable pad 108, and a trim part 110. The die part 104 is fixed to the die holder 102. The die portion 104 has a forming surface 104a for forming the work 500, facing the forming surface 204a of the punch 204. The molding surface 104a is an example of a second molding surface. The die portion 104 is disposed along the molding surface 104a, and has a flow passage 109 through which a coolant for cooling the work 500 flows. The movable pad 108 has a flow passage 113 through which a coolant for cooling the work 500 flows. The upper mold 100 does not need to have the movable pad 108. The lower mold 200 may not have the blank holder 206.

  The trim part 110 may be formed integrally with the die part 104. This can suppress a decrease in the strength of the die portion 104. The trim portion 110 may be integrally formed with the die portion 104 by extending from the molding surface 104a and being fixed to the fixing surface 104b of the die portion 104 facing the blank holder 206. The trim part 110 may be detachably fixed to the fixing surface 104b of the die part 104 via a bolt 130. Thereby, replacement of the trim part 110 can be easily performed. The trim part 110 may be physically integrated with the die part 104. The trim part 110 may be made of the same material as the die part 104 and physically integrated. Here, the phrase “the trim portion 110 is integrally formed with the die portion 104” means that the trim portion 110 and the die portion 104 are physically integrally formed of the same material. The concept includes a form in which the trim portion 104 and the die portion 104 are integrally connected by bolting, bonding, or the like.

  The trim part 110 has a blade part 110a for cutting the end part 502 of the work 500. The trim part 110 has a blade part 110a on a side part on the molding surface 104a side. The trim portion 110 further includes a protruding portion 112 that forms a step from the blade portion 110a toward the blank holder 206. The protruding portion 112 has a holding surface 110b opposed to the support surface 206a of the blank holder 206 and holding the end portion 502 of the work 500 between itself and the support surface 206a. The holding surface 110b protrudes toward the blank holder 206 from the blade portion 110a. The cross section of the corner of the protrusion 112 on the molding surface 204a side may be curved.

  As shown in FIG. 3A, the end 502 of the work 500 is held between the support surface 206a of the blank holder 206 and the holding surface 110b of the protrusion 112, and one end of the work 500 is held between the movable pad 108 and the punch 204. The pressing pressure 111 is applied to the die holder 102 with the portion held therebetween. Thereby, as shown in FIG. 3B, the die part 104 and the trim part 110 move toward the lower mold 200, and the blank holder 206 moves along the side surface 204b of the punch 204.

  The work 500 is sandwiched between the die portion 104 and the punch 204, and is pressed by the forming surface 204a and the forming surface 104a to be formed into a predetermined shape. Then, as shown in FIG. 3C, before the die portion 104 and the trim portion 110 reach the bottom dead center, the blade portion 110a cuts the end portion 502 of the workpiece 500. The blade portion 110a may cut the end portion 502 of the work 500 immediately before the die portion 104 and the trim portion 110 reach the bottom dead center. When the upper die 100 functions as the first die, the work 500 moves toward the lower die 200 that functions as the second die while being clamped, and is formed and cut.

  The heated work 500 is formed toward the forming surface 204a of the punch 204 while being pressed. If the work 500 is in contact with the blade 110a while the work 500 is pressed, the blade 110a is easily worn due to friction with the work 500. Therefore, the trim portion 110 includes a protruding portion 112 having a clamping surface 110b protruding from the blade portion 110a toward the blank holder 206. Thus, before the work 500 is cut, the work 500 is less likely to come into contact with the blade 110a during pressing. Therefore, it is possible to suppress wear of the blade portion 110a due to friction with the work 500.

  The trim portion 110 is fixed to a fixing surface 104b of the die portion 104 extending from the molding surface 104a and facing the blank holder 206. The trim part 110 is fixed to the die part 104, not the die holder 102. Thus, the width of the die 104 is not limited to the width of the flange of the press-formed product. Therefore, the flow passage 109 through which the coolant such as water flows can be provided inside the die portion 104 without being restricted by the width of the flange portion of the press-formed product. Thereby, even if the flow passage 109 is provided, it is possible to suppress the strength of the die portion 104 from being reduced.

  Further, according to the press forming apparatus according to the present embodiment, there is no need to provide a hydraulic tanker for adjusting the position of the trim section 110 and the die section 104. Therefore, the mold can be downsized.

  As shown in FIG. 4, the forming surface 104a of the die portion 104 includes a step portion 104c for bending the work 500 to form a flange portion. The step portion 104c is formed by rising from an end portion for forming the flange portion of the forming surface 104a. The blade portion 110a may be provided inside a virtual tangent line 610 that contacts the corner portion 112d of the protruding portion 112 and the step portion 104c as indicated by a portion surrounded by reference numeral 612. The blade 110a may be provided inside a tangent plane that contacts the corner 112d and the step 104c. Note that, in some cases, a result in which the forming analysis line exists outside the tangent line as in the work 500 shown in FIG. 4 is obtained by the forming analysis. In this case, the blade portion 110a may be provided outside the tangent line 610 as long as it is provided inside the forming analysis line. Thereby, before the blade part 110a cuts the workpiece 500, the work 500 can be more reliably prevented from being dragged in contact with the blade part 110a. Therefore, wear of the blade portion 110a can be more reliably suppressed.

  As described above, the present invention has been described using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is apparent to those skilled in the art that various changes or improvements can be made to the above embodiment. It is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

  The execution order of each processing such as operation, procedure, step, and stage in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “before”. It should be noted that they can be realized in any order as long as the output of the previous process is not used in the subsequent process. Even if the operation flow in the claims, the description, and the drawings is described using “first”, “next”, etc. for convenience, it means that it is essential to implement in this order is not.

Reference Signs List 10 Upper die 12 Die holder 14 Trim die 14a Nipping surface 14b Blade 16 Pad 16a Molding surface 16c Thickness 19 Flow passage 20 Reaction force generator 30 Lower die 32 Punch holder 34 Punch 34a Molding surface 36 Blank holder 36a Support surface 38 Reaction force Generator 39 Flow path 50 Work 52 End 54 Flange 100 Upper die 102 Die holder 104 Die 104a Molding surface 104b Fixed surface 104c Step 108 Movable pad 109 Flow passage 110 Trim 110a Blade 110b Clamping surface 112 Projection 112d Corner 113 Flow passage 130 Bolt 200 Lower die 202 Punch holder 204 Punch 204a Molding surface 204b Side surface 206 Blank holder 206a Support surface 208 Reaction force generator 209 Flow passage 500 Work 502 End 610 Tangential line

Claims (7)

A press forming apparatus that presses and forms a heated work while cooling the work,
A first mold supporting the work;
A second mold disposed opposite to the first mold,
The first type is
A punch having a first molding surface for molding the work,
A blank holder that is movably disposed along a side surface extending from the first molding surface of the punch and has a support surface that supports an end of the work;
Having the second type,
A die facing the first molding surface and having a second molding surface for molding the work, and a fixed surface extending outward from a tip portion of the second molding surface and facing the support surface of the blank holder; Department and
A trim portion integrally formed with the die portion,
The trim section has a blade section for cutting the end of the work,
The die portion has a flow passage for flowing a coolant for cooling the work, along the second forming surface,
The trim part, the by being fixed to the fixing surface, the die portion and is integrally formed,
Before SL trim part has a holding surface for clamping the end portion of the workpiece between the opposed to the supporting surface the support surface, projecting said clamping face projects into the blank holder side of the cutting portion Press forming apparatus further comprising a part. The second forming surface includes a step portion for forming the flange portion by bending the work,
The press-forming device according to claim 1, wherein the blade portion is provided inside a tangent line that contacts a corner portion of the protruding portion and the step portion.   With the end portion of the work held between the support surface of the blank holder and the holding surface of the projecting portion, the die portion and the trim portion are moved toward the first mold, By moving the blank holder along the side surface of the punch, the work is pressed and formed by the first forming surface and the second forming surface, and the die portion and the trim portion are moved to the bottom dead center. The press-forming apparatus according to claim 1, wherein the blade cuts the end of the work before reaching the workpiece. The press-forming device according to any one of claims 1 to 3, wherein the fixed surface of the die portion continuously extends outward from a tip portion of the second forming surface. The press molding device according to any one of claims 1 to 3, wherein the trim portion is detachably fixed to the fixing surface of the die portion. A method for manufacturing a press-formed product by pressing and molding a heated work while cooling it while sandwiching it between a first mold and a second mold,
The first mold is arranged movably along a punch having a first molding surface for molding the work and a side surface extending from the first molding surface of the punch, and supports an end of the work. With a blank holder having a support surface,
The second mold is opposed to the first molding surface, and has a second molding surface for molding the work, and extends outward from a distal end portion of the second molding surface and faces the support surface of the blank holder. A die portion having a fixed surface, and a trim portion integrally formed with the die portion,
The trim section has a blade section for cutting the end of the work,
The die portion has a flow passage for flowing a coolant for cooling the work, along the second forming surface,
The trim part, the by being fixed to the fixing surface, the die portion and is integrally formed,
Before SL trim part has a clamping face for clamping the end portion of the workpiece between the opposed to the supporting surface the support surface, projecting said clamping face projects into the blank holder side of the cutting portion Part further,
The method of manufacturing,
With the end portion of the work held between the support surface of the blank holder and the holding surface of the trim portion, the die portion and the trim portion are moved toward the first mold, By moving the blank holder along the side surface of the punch, the work is pressed and formed by the first forming surface and the second forming surface, and the die portion and the trim portion are moved to the bottom dead center. A manufacturing method comprising: a step of cutting the end of the workpiece by the blade before reaching the workpiece. The manufacturing method according to claim 6, wherein the trim portion is detachably fixed to the fixing surface of the die portion.

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