JP2014050857A - Warm drawing apparatus and warm drawing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a warm drawing apparatus and a warm drawing method in which a molding limit of a blank material is high.SOLUTION: The warm drawing apparatus supports the blank material B made of an aluminum plate material by a die 12 and a blank holder 13, makes a punch 14 approach the die 12, and draws the blank material B. Drawing beads 12a and 13a for adjusting an inflow quantity of the blank material B when performing the drawing, are formed in the die 12 and the blank holder 13. In the die 12 and the blank holder 13, projection parts 12b and 13b and recessed parts 12c and 13c are formed so that in a part where one of the die 12 and the blank holder 13 comes in contact with the blank material B, the other does not come in contact with its reverse surface, with respect to the blank material B located more on the outer edge side from the drawing beads 12a and 13a.

Description

  The present invention relates to a warm drawing apparatus and a warm drawing method, and more particularly to a warm drawing apparatus and a warm drawing method for heating and drawing a blank material made of a metal plate.

  In recent years, automobiles have been made lighter in weight to reduce fuel consumption. As one of them, an attempt has been made to adopt a lighter aluminum sheet-formed panel for an automobile body sheet that has conventionally used mild steel sheets or the like. However, an aluminum plate is inferior in formability compared with a mild steel plate, and it has been difficult to form a portion having a complicated shape or a portion having a deep side wall in an automobile body sheet.

  As a method for forming a metal plate such as an aluminum plate, press draw forming by warm forming has been developed (see, for example, Patent Document 1). In Patent Document 1, the surface temperature of the die and the blank holder is set to 180 ° C. or more and 300 ° C. or less, and the surface temperature of the punch is set to be 20 ° C. to 250 ° C. lower than the surface temperature of the die or the blank holder. The blank material is heated by bringing the punch into contact with the blank material.

  In the warm forming described in Patent Document 1, in order to uniformly heat the blank material in a short time, a die and a blank holder are brought into surface contact from both sides on the entire flange portion where the blank material is drawn, and the die and Heat is transferred from the blank holder to the blank. Further, a wrinkle presser load is obtained by frictional resistance by sandwiching the entire flange portion between a die and a blank holder, and shape defects such as wrinkles and springback during press forming are suppressed.

  The frictional resistance between the die and the blank holder and the blank material has a large variation due to the flatness of the die and the blank holder and unevenness in the application of the lubricating oil, and is difficult to manage. For this reason, in a normal cold press die, irregularities called squeeze beads are provided on the outer periphery of the product shape, and the inflow amount of the blank material may be adjusted by pinching the squeeze bead. And the thing which provides a gradient in a blank holder and makes a friction resistance small is made not to contact a blank material and a blank holder in the outer edge side from an aperture bead (for example, refer patent document 2).

JP 7-90293 A JP-A-48-49660

  Here, in warm forming, as described in Patent Document 2, if the blank holder is provided with a gradient to increase the clearance between the die and the blank holder, the frictional resistance between the mold and the blank material can be reduced. The blank material cannot be effectively heated by the die and the blank holder.

  An object of this invention is to provide the warm drawing apparatus and warm drawing method which have a high shaping | molding limit of a blank material.

In order to solve the above problems, a warm drawing apparatus according to the first aspect of the present invention provides:
A warm drawing apparatus for heating and drawing a blank made of a metal plate,
A die bead and a blank holder are formed on the die and the blank holder, and a drawn bead for adjusting an inflow amount of the blank material at the time of drawing is formed, and the blank material on the outer edge side from the drawn bead. Is a mold that supports the blank material by holding the squeeze bead without clamping,
A punch that presses the blank material relatively closer to the mold; and
Heating means for heating the blank material on the outer edge side from the squeezed bead;
It is characterized by providing.
Here, as the “metal plate”, for example, various types such as a pure aluminum plate, an alloy plate mainly composed of aluminum, a steel plate, and a copper plate can be used.

Each of the die and the blank holder has a convex portion that contacts the blank material and the blank material so that the other does not contact the blank material on the outer edge side of the squeeze bead. And a recess that does not contact the
The heating means may heat the blank material by heating at least one of the die and the blank holder.

  Further, each of the die and the blank holder has a portion where both the die and the blank holder do not contact around the portion where one of the die contacts the blank material on the outer edge side from the drawing bead. The convex portion and the concave portion may be formed on the surface.

  Moreover, when the said metal mold | die supports the said blank material, each said convex part of the said die | dye and the said blank holder may be closely approached to the distance smaller than the thickness of the said blank material.

  Further, the heating means may spray a gas heated to a predetermined temperature toward the blank material on the outer edge side from the squeezed bead.

Further, an aluminum plate may be used as the blank material.
Here, the “aluminum plate” includes not only pure aluminum but also an alloy plate mainly composed of aluminum.

The warm drawing method according to the second aspect of the present invention is:
A warm drawing method for heating and drawing a blank material made of a metal plate,
A die and a blank holder, and the die and the blank holder have a die bead that adjusts an inflow amount of the blank material during draw forming, and is outside the draw bead. The step of arranging the blank material so that the blank material is pinched in the drawn bead without being sandwiched about the blank material on the edge side,
Heating the blank material on the outer edge side of the drawn bead;
Pressing the blank with a punch relatively close to the mold; and
It is characterized by including.

Each of the die and the blank holder has a convex portion that contacts the blank material and the blank material so that the other does not contact the blank material on the outer edge side of the squeeze bead. And a recess that does not contact the
In the heating step, the blank material may be heated by heating at least one of the die and the blank holder.

  Further, each of the die and the blank holder has a portion where both the die and the blank holder do not contact around the portion where one of the die contacts the blank material on the outer edge side from the drawing bead. The convex portion and the concave portion may be formed on the surface.

  In the step of disposing the blank material on the mold, the convex portions of the die and the blank holder may be brought closer to a distance smaller than the thickness of the blank material.

  Further, in the heating step, a gas heated to a predetermined temperature may be sprayed toward the blank material on the outer edge side from the squeeze bead.

  Further, an aluminum plate may be used as the blank material.

  ADVANTAGE OF THE INVENTION According to this invention, the warm drawing forming apparatus and warm drawing method which have a high shaping | molding limit of a blank material can be provided.

It is a figure which shows typically the structure of the warm drawing apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the draw bead periphery of the warm shaping | molding metal mold | die which concerns on embodiment. It is sectional drawing which expands and shows the convex part and recessed part of die | dye and a blank holder. It is sectional drawing which shows the draw bead periphery of the metal mold | die for warm forming which concerns on a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram schematically showing a configuration of a warm drawing apparatus 10 according to an embodiment of the present invention. As shown in FIG. 1, the warm drawing apparatus 10 includes a die 11 including a die 12 and a blank holder 13, a punch 14, a lubricant application mechanism 15, and a control unit 16. In this warm drawing apparatus 10, the lubricant is applied to the surface of the blank B made of, for example, an aluminum plate by the lubrication application mechanism 15, and a part of the blank B is sandwiched between the die 12 and the blank holder 13. Then, the blank material B is pressed and drawn by bringing the die 12 and the punch 14 close to each other. The control unit 16 can be constituted by, for example, a known computer and controls the entire apparatus.

  A heater 17 is provided in each of the die 12, the blank holder 13, and the punch 14. The control unit 16 controls the heater 17 to control the temperatures of the die 12, the blank holder 13, and the punch 14, and heats the blank material B through the die 12, the blank holder 13, and the punch 14.

  As shown in FIG. 2, squeeze beads 12a and 13a are formed on the die 12 and the blank holder 13, respectively. The squeezing beads 12a and 13a are composed of a convex portion 12a formed on the die 12 and a concave portion 13a formed on the blank holder 13 corresponding to the convex portion 12a. When the blank material B is sandwiched between the die 12 and the blank holder 13, the blank material B is sandwiched between the drawn beads 12a and 13a, and the blank material B is plastically deformed. Thereby, when the blank material B is drawn, the inflow amount into which the blank material B flows can be adjusted, and the occurrence of shape defects such as wrinkles and spring back can be suppressed. In addition, the shape of the drawn bead is arbitrary as long as the blank material B can be clamped to adjust the amount of inflow of the blank material B during drawing, and for example, a concave portion is formed in the die 12 and the blank holder 13 is formed. Convex portions may be formed on the die 12, or a plurality of pairs of convex portions and concave portions may be formed on the die 12 and the blank holder 13.

  In the present embodiment, as shown in FIG. 2 and FIG. 3, each of the die 12 and the blank holder 13 has convex portions 12 b and 13 b that are in contact with the blank material B on the outer edge side of the squeeze beads 12 a and 13 a, Concave portions 12c and 13c that do not contact the blank material B are alternately formed. The convex portions 12b and 13b and the concave portions 12c and 13c of the die 12 and the blank holder 13 are such that one of the die 12 and the blank holder 13 becomes the convex portions 12b and 13b, and the other becomes the concave portions 12c and 13c. Is formed. That is, the die 12 and the blank holder 13 are arranged so that the both sides of the blank material B are not sandwiched between the die 12 and the blank holder 13 on the outer edge side of the drawn beads 12a and 13a. In the portion where one of the two contacts the blank material B, the other is not in contact with the back surface.

  Further, as shown in FIG. 3, the die 12 and the blank holder 13 have the die 12 and the blank holder 13 around the portion where the projections 12 b and 13 b of the blank holder 13 contact the blank material B. The part which becomes the recessed parts 12c and 13c, respectively is formed so that both 13 may have the part which does not contact the blank material B. In other words, one convex portion 12b (13b) of the die 12 and the blank holder 13 is configured to be located inside a line segment connecting the other adjacent convex portions 13b (12b). For example, in the example shown in FIG. 3, the convex part 12b (Wb1) of the die 12 is located inside a line segment Wc2 connecting the convex parts 13b of the blank holder 13, and the convex part 13b (Wb2) of the blank holder 13 is It is located inside the line segment Wc1 connecting the convex portions 12b of the die 12.

  In the warm drawing apparatus 10 of the present embodiment, the outer edge side of the drawn beads 12a and 13a of the blank B is configured so that the other does not come into contact with the portion where one of the die 12 and the blank holder 13 is in contact. The frictional resistance between the blank material B and the mold 11 can be reduced, and heat can be transmitted from the convex portions 12b and 13b in contact with the blank material B to heat the outer edge side of the drawn beads 12a and 13a. Therefore, with such a configuration, the molding limit of the blank material B can be improved. In addition, in the present embodiment, a portion in which both the die 12 and the blank holder 13 do not contact the blank material B is formed around a portion where one convex portion 12b, 13b of the die 12 and the blank holder 13 contacts the blank material B. The contact surface pressure between the die 12 and the blank holder 13 and the blank material B can be increased without causing the blank material B to be plastically deformed. Heat can be effectively transferred to B, and the blank material B can be heated in a short time. For example, when the blank material B is supported by the die 12 and the blank holder 13, the clearance (distance) between the convex portion 12 b of the die 12 and the convex portion 13 b of the blank holder 13 is blank so long as the blank material B is not plastically deformed. The distance may be reduced to a distance smaller than the thickness of the material B. Moreover, when the part which both the die | dye 12 and the blank holder 13 do not contact the blank material B is fully ensured, the convex part 12b of the die | dye 12 and the blank holder 13 are the range which does not plastically deform the blank material B. The die 12 and the blank holder 13 may be brought close to each other until the clearance with the convex portion 13b becomes negative (the convex portions 12b and 13b of the die 12 and the blank holder 13 enter the other concave portions 13c and 12c).

  Here, although the ratio of the convex portions 12b and 13b and the concave portions 12c and 13c is such that the larger the proportion occupied by the convex portions 12b and 13b, the more heat can be applied to the blank material B, but the blank material B and the mold Therefore, the ratio of the desired convex portions 12b and 13b may be obtained by experiments or the like. Similarly, the interval between the convex portions 12b and 13b and the concave portions 12c and 13c may be determined to be the desired interval between the convex portions 12b and 13b through experiments or the like. Furthermore, each of the convex portions 12b and 13b and the concave portions 12c and 13c may be formed long in a predetermined direction, and the convex portions 12b and 13b and the concave portions 12c and 13c may be alternately formed in the short direction. The convex portions 12b and 13b and the concave portions 12c and 13c may be formed so that the convex portions 12b and 13b are arranged in a lattice shape.

  The present invention is not limited to the above embodiment, and various modifications and applications are possible. For example, in the warm drawing apparatus 10 of the above-described embodiment, as a method of heating the blank material B on the outer edge side from the drawn beads 12a, 13a, the blanks are formed from the convex portions 12b, 13b formed on the die 12 and the blank holder 13. Heat is transferred to the material B. Instead of or in addition to this, as shown in FIG. 4, the blank material B on the outer edge side of the drawn beads 12a and 13a is heated to a predetermined temperature. A blower 18 for blowing the generated gas may be provided. In the example shown in FIG. 4, the blank holder 113 is configured so as not to be in contact with the blank B on the outer edge side of the drawn beads 12 a and 13 a and is not sandwiched between the die 112 and the blank holder 113. The gas heated from the blower 18 is blown into the gap between the material B and the blank holder 113, and the blank material B on the outer edge side of the drawn beads 12a and 13a is heated. In such a case as well, the blank material B on the outer edge side of the drawn beads 12a and 13a can be heated and the frictional resistance between the mold 11 and the blank material B, as in the warm drawing apparatus 10 of the embodiment described above. The molding limit of the blank material B can be improved.

  Such a blower 18 is configured such that, on the outer edge side of the drawn beads 12a and 13a, the blank material B and the die 112 are not in contact with each other, and the heated gas is sent to the gap between the blank material B and the die 112. As shown in FIG. 3, when convex parts 12b, 13b and concave parts 12c, 13c are formed on the die 12 and the blank holder 13, heated gas may be sent to the concave parts 12c, 13c. .

  In the embodiment described above, the heater 17 is incorporated in the mold 11 and the punch 14. For example, high-temperature oil is circulated inside the mold 11 and the punch 14 to heat the mold 11 and the punch 14. May be. The heating temperature of the blank material B should just be the temperature which the intensity | strength of the aluminum plate which is the blank material B falls, for example, can be set as the temperature of 150 degreeC or more. When the blank material B is heated by the mold 11 in a short time, the temperature of the mold 11 is preferably set to a temperature higher by about 10 to 50 ° C. than the target temperature of the blank material B. In order to prevent the blank material B from adhering to the mold 11 due to deterioration of the performance of the lubricant, it is preferable to set the temperature to, for example, 300 ° C. or less.

  Further, the heater 17 for heating the blank B is provided only on one of the die 12 and the blank holder 13 in the mold 11, and the outer edge side from the squeezing beads 12 a and 13 a through one of the die 12 and the blank holder 13. It may be heated. Further, depending on the blank material B, the molding limit of the blank material B can be improved by not heating the punch 14 or cooling the punch 14. For this reason, the punch 14 may not be provided with the heater 17, and a mechanism for cooling the punch 14 may be provided instead of or in addition to the heater 17.

  As the material of the aluminum plate used as the blank material B, JIS 1000 series, 2000 series, 3000 series, 5000 series, 6000 series and 7000 series aluminum alloys can be applied. With such an aluminum plate, press molding can be performed under the above-described conditions, but conditions such as the heating temperature by the heater 17 may be changed according to the material. What is necessary is just to use what was suitably defined for the shape of the blank material B based on the shape of a manufactured product, etc., for example, a board thickness can use 0.6 mm-2.5 mm. Note that aluminum plate materials having a plate thickness of less than 0.6 mm or greater than 2.5 mm are not often used as automobile body sheet materials. In the above-described embodiment, an aluminum plate material is used as the blank material B. However, various metal plates such as a steel plate and a copper plate may be used as the blank material B. Also in this case, the temperature of the heating condition of the blank B may be changed according to the material.

  Although the embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and examples, and various modifications (within the scope not departing from the gist of the present invention) Needless to say, it may be possible to include deletion of a component.

DESCRIPTION OF SYMBOLS 10 Warm drawing apparatus 11 Mold 12 Die 13 Blank holder 12a, 13a Drawing bead 12b, 13b Convex part 12c, 13c Concave part 14 Punch 15 Lubricant application mechanism 16 Control part 17 Heater 18 Blower 112 Die 113 Blank holder B Blank material

Claims (12)

A warm drawing apparatus for heating and drawing a blank made of a metal plate,
A die bead and a blank holder are formed on the die and the blank holder, and a drawn bead for adjusting an inflow amount of the blank material at the time of drawing is formed, and the blank material on the outer edge side from the drawn bead. Is a mold that supports the blank material by holding the squeeze bead without clamping,
A punch that presses the blank material relatively closer to the mold; and
Heating means for heating the blank material on the outer edge side from the squeezed bead;
A warm drawing apparatus characterized by comprising: Each of the die and the blank holder has a convex portion that contacts the blank material and the blank material so that the other does not contact the blank material on the outer edge side of the squeeze bead. And a recess that does not contact the
The heating means heats the blank material by heating at least one of the die and the blank holder.
The warm drawing apparatus according to claim 1. Each of the die and the blank holder has a portion where both the die and the blank holder do not contact around the portion where one of the die contacts the blank material on the outer edge side from the drawing bead. A convex part and the concave part are formed,
The warm drawing apparatus according to claim 2. When the mold supports the blank material, the convex portions of the die and the blank holder are brought closer to a distance smaller than the thickness of the blank material,
The warm drawing apparatus according to claim 3. The heating means blows a gas heated to a predetermined temperature toward the blank material on the outer edge side of the squeeze bead,
The warm drawing apparatus according to any one of claims 1 to 4, wherein: An aluminum plate is used as the blank material.
The warm drawing apparatus according to any one of claims 1 to 5, wherein the apparatus is a warm drawing apparatus. A warm drawing method for heating and drawing a blank material made of a metal plate,
A die and a blank holder, and the die and the blank holder have a die bead that adjusts an inflow amount of the blank material during draw forming, and is outside the draw bead. The step of arranging the blank material so that the blank material is pinched in the drawn bead without being sandwiched about the blank material on the edge side,
Heating the blank material on the outer edge side of the drawn bead;
Pressing the blank with a punch relatively close to the mold; and
A method of warm drawing, comprising: Each of the die and the blank holder has a convex portion that contacts the blank material and the blank material so that the other does not contact the blank material on the outer edge side of the squeeze bead. And a recess that does not contact the
In the heating step, the blank material is heated by heating at least one of the die and the blank holder.
The warm drawing method according to claim 7, wherein: Each of the die and the blank holder has a portion where both the die and the blank holder do not contact around the portion where one of the die contacts the blank material on the outer edge side from the drawing bead. A convex part and the concave part are formed,
The warm drawing method according to claim 8, wherein: In the step of arranging the blank material in the mold, the convex portions of the die and the blank holder are brought closer to a distance smaller than the thickness of the blank material,
The warm drawing method according to claim 9. In the heating step, a gas heated to a predetermined temperature is blown toward the blank material on the outer edge side from the squeezed bead.
The warm drawing method according to any one of claims 7 to 10, wherein: An aluminum plate is used as the blank material.
The warm drawing method according to any one of claims 7 to 11, wherein the method is a warm drawing method.

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