JP2006130511A - Apparatus for warm press forming - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for warm press forming, which can prevent the degradation of the quality of a formed workpiece. <P>SOLUTION: The apparatus 10 for warm press forming comprises a lower die block 11 and an upper die block 12 capable of vertically moving with respect to the lower die block 11, and forms the workpiece by means of a punch 13 and a die 14. A plurality of heaters 25, 31 are buried in the portions which are located around the punch 13 in at least any one of the lower die block 11 and the upper die block 12, and are arranged in the direction along the outside wall surface 13b of the punch 13. By this configuration, the portions located around the punch 13 are uniformly heated, and the heat is uniformly transferred to the neighborhood of the portions around the punch 13, that is to say, to the peripheral portions of the workpiece, and also is transferred to the middle portion of the workpiece. As a result, the whole of the workpiece is uniformly heated, and the temperature differences between the portions of the workpiece are not caused. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a warm press molding apparatus that processes a workpiece with a punch and a die.

The warm press forming apparatus is an apparatus for deforming a workpiece made of, for example, a magnesium alloy using a punch and a die. As such a warm press molding apparatus, for example, a punch, a die, or a blank holder provided on the outer periphery of the punch is embedded in a heater. This warm press forming apparatus sandwiches a workpiece between a punch and a die and heats it with a heater. After heating to a predetermined temperature, the workpiece is press-molded using the punch and the die (Patent Documents 1 to 3). 4).
Japanese Patent Laid-Open No. 2004-136306 JP 2003-170227 A JP 2003-103311 A JP-A-6-55230

  By the way, when a workpiece is heated to a predetermined temperature using a conventional warm press forming apparatus, a portion near the heater of the workpiece is remarkably heated and heated while a portion other than the portion near the heater of the workpiece is gradually heated and heated. To do. Therefore, since the heated workpiece has a temperature difference depending on the part, it is difficult to uniformly heat and raise the temperature. As a result, there is a possibility that the quality of the molded workpiece is deteriorated.

  The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a warm press forming apparatus capable of preventing the quality deterioration of a formed workpiece.

The present invention employs the following means in order to solve the above problems. That is, the present invention provides a warm press molding apparatus in which an upper mold is provided so as to be movable up and down with respect to a lower mold, and a workpiece is processed by a punch and a die, and is at least one of the lower mold and the upper mold A plurality of heaters are embedded in a portion along the outer wall surface of the punch in a portion located around the punch.
By adopting such a configuration, the part located around the punch is uniformly heated, and the heat is uniformly transmitted to the vicinity of the part located around the punch, that is, the peripheral edge of the work. Evenly transmitted to the center. As a result, the entire workpiece is heated uniformly, so that a temperature difference due to the portion of the workpiece does not occur.

In the warm press molding apparatus according to the present invention, the heater is embedded in a blank holder having an opening and in a direction along the inner wall surface of the opening.
With such a configuration, the inner wall surface of the opening of the blank holder is uniformly heated, and the heat is uniformly transmitted to the vicinity of the inner wall surface of the opening, that is, the peripheral edge of the work, and the center of the work Evenly transmitted to the part. As a result, the entire workpiece is heated uniformly, so that a temperature difference due to the portion of the workpiece does not occur.

Further, in the warm press molding apparatus according to the present invention, the heater is embedded in a die having a receiving portion for receiving the punch and along the inner wall surface of the receiving portion. .
With this configuration, the inner wall surface of the receiving portion of the die is uniformly heated, and the heat is uniformly transmitted to the vicinity of the inner wall surface of the receiving portion, that is, the peripheral edge portion of the workpiece, and the center portion of the workpiece. Evenly transmitted. As a result, the entire workpiece is uniformly heated, so that a temperature difference due to the portion of the workpiece does not occur.

  According to the warm press molding apparatus of the present invention, the entire workpiece can be made uniform by uniformly heating a portion located around the punch, for example, the inner wall surface of the opening of the blank holder or the inner wall surface of the receiving portion of the die. The temperature difference between the parts of the workpiece does not occur and the quality of the molded workpiece can be prevented from being deteriorated.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
The warm press molding apparatus 10 includes a lower mold 11 and an upper mold 12 provided to be movable up and down with respect to the lower mold 11. As will be described later, this warm press forming apparatus 10 is for drawing a workpiece W made of a magnesium alloy plate by a punch 13 provided in a lower die 11 and a die 14 provided in an upper die 12. .

The lower mold 11 includes a bolster 15 for fixing the lower mold 11 to a lower bed (not shown), a plurality of, for example, four column portions 16 erected on the bolster 15 and arranged at predetermined positions, and columns. A rectangular plate 17 supported at each corner is provided at the upper end of the portion 16. A heat insulating member 18 formed in a rectangular plate shape is installed on the upper surface of the plate 17.
A rectangular punch plate 19 having a predetermined thickness is placed on the upper surface of the heat insulating member 18, and has an outer wall surface 13 a and a predetermined height at the center of the rectangular punch plate 19. A punch 13 protruding upward is attached. A punch die 13b for forming the workpiece W into a predetermined shape is formed on the upper surface of the punch 13.

  On the upper surface of the punch plate 19, a rectangular blank holder 20 having a predetermined thickness and having an opening 20a at the center is placed so as to be movable in the vertical direction together with a support portion 23 described later. Here, the opening 20 a has an inner wall surface 20 b that holds a certain gap with the outer wall surface 13 a of the punch 13 so that the punch 13 can be penetrated. That is, the blank holder 20 is positioned around the punch 13 and can move in the vertical direction while maintaining a certain gap with the outer wall surface 13a of the punch 13.

Further, a cylindrical through hole 15a penetrating in the vertical direction is provided at the center of the bolster 15, and a cylindrical lockout pin 21 is provided in the through hole 15a. A lockout 22 having a predetermined thickness and formed in a rectangular plate shape is attached to the upper end of the lockout pin 21.
A plurality of, for example, two support portions 23 connected to the end portion of the bottom surface of the blank holder 20 are provided upright at each corner portion of the upper surface of the lockout 22. Accordingly, the lockout pin 21, the lockout 22, the support portion 23, and the blank holder 20 are integrally movable in the vertical direction. The plate 17, the heat insulating member 18, and the punch plate 19 are provided with through holes 17 a, 18 a, and 19 a at portions through which the support portions 23 pass.

  A plurality of, for example, four heater insertion holes 24 are formed in the blank holder 20 in an elongated shape. These heater insertion holes 24 extend from the respective outer wall surfaces of the blank holder 20 in a direction along the inner wall surface 20b of the opening 20a, and are arranged so as to surround the opening 20a. Electric heaters 25 are embedded in the heater insertion holes 24, respectively.

The upper mold 12 is provided with a slide base 26 for fixing the upper mold 12 to an upper bed (not shown). The slide base 26 has a predetermined thickness and is formed in a rectangular plate shape. A rectangular plate having a predetermined thickness is attached to the lower surface of the slide base 26. Further, a heat insulating member 28 formed in a rectangular plate shape is installed on the lower surface of the plate 27.
A rectangular die plate 29 having a predetermined thickness is installed on the lower surface of the heat insulating member 28, and a die 14 protruding downward with a predetermined height is attached to the lower surface of the die plate 29. Yes. A recess 14 a (receiving portion) that has an inner wall surface 14 b and receives the punch 13 is formed inside the die 14. A die die 14c for forming the workpiece W into a predetermined shape is formed on the bottom surface of the recess 14a so as to correspond to the punch die 13b.

  A plurality of, for example, four heater insertion holes 30 are formed in the die 14 in an elongated shape. These heater insertion holes 30 extend from the respective outer wall surfaces of the die 14 in a direction along the inner wall surface 14b of the recess 14a, and are arranged so as to surround the recess 14a. Electric heaters 31 are respectively embedded in the heater insertion holes 30.

Next, the operation of the warm press forming apparatus having the above configuration will be described.
When the workpiece W is warm press-molded, the workpiece W is heated for a predetermined time while being sandwiched between the lower die 11 and the upper die 12, and then the heated workpiece W is press-molded. That is, the following procedure is used. FIG. 6 is a diagram for explaining the procedure.
As shown in FIG. 6 (a), a plate-like workpiece W made of a magnesium alloy is placed at an appropriate position on the upper surface of the blank holder 20 of the lower die 11 with the lower die 11 and the upper die 12 being separated from each other. To do. Then, the upper die 12 is lowered, the workpiece W is sandwiched between the blank holder 20 and the die 14, and the heaters 25 and 31 embedded in the blank holder 20 and the die 14 are turned on, and the workpiece W is blanked for a predetermined time. The holder 20 and the die 14 are heated to the set heating temperature.

Thereafter, with the heated workpiece W sandwiched between the blank holder 20 and the die 14, the upper die 12 is further lowered together with the blank holder 20 at a constant molding speed, and the lower surface of the workpiece W is punched by the punch 13. Then, the upper die 12 is lowered together with the blank holder 20 at a constant molding speed so that the upper surface of the workpiece W is brought into contact with the die die 14 b of the die 14. Then, as shown in FIG. 6B, the work W is press-molded into a predetermined shape while the upper and lower surfaces of the work W are kept in contact with the punch die 13b and the die die 14b for a predetermined time.
After the press molding of the workpiece W is finished, the pressure is held, and after a predetermined time has elapsed, as shown in FIG. 6C, the upper die 12 is raised to separate the die 14 from the blank holder 20, The molded product of the workpiece W remaining on the upper surface of the punch 13 is taken out.

Here, as the setting conditions when the workpiece W is warm-pressed as described above, the setting heating time of the blank holder 20 and the die 14 is 200 to 350 ° C., the heating time of the workpiece W is 1 to 20 sec, and the forming speed is It is preferable to set it as 1-30 mm / sec. In order to realize such a forming speed, it is preferable to use a hydraulic press machine for the warm press forming apparatus 10.
The material used for the punch 13 and the die 14 is preferably SKD11.
The lubricant used in the warm press molding apparatus 10 preferably has heat resistance and lubrication performance.

  In this case, the inner wall surface 20b of the opening 20a of the blank holder 20 is uniformly heated, and the heat is uniformly transmitted to the vicinity of the inner wall surface 20b, that is, the peripheral edge of the workpiece W, and also to the central portion of the workpiece W. Communicated. Further, the inner wall surface 14b of the concave portion 14a of the die 14 is uniformly heated, and the heat is uniformly transmitted to the vicinity of the inner wall surface 14b, that is, to the peripheral portion of the workpiece W, and also uniformly transmitted to the center portion of the workpiece W. Is done. As a result, since the entire workpiece W is heated uniformly, a temperature difference due to the portion of the workpiece W does not occur. Accordingly, it is possible to prevent the quality of the work W formed into a predetermined shape by the warm press forming apparatus 10 from being deteriorated.

In the above embodiment, the warm press molding apparatus 10 can be applied to processes other than the drawing process.
Moreover, in the said embodiment, although the heaters 25 and 31 are each embed | buried under the blank holder 20 and the die | dye 14, if the whole workpiece | work W can be heated uniformly, the blank holder 20 and the die | dye 14 It suffices if it is embedded in at least one of them. Further, the heaters 25 and 31 are not limited to the electric type as long as they can be embedded in the blank holder 20 and the die 14 and used.

  Moreover, in the said embodiment, when using the heat insulation members 18 and 28 for the warm press molding apparatus 10, in order to stabilize temperature and suppress the influence with respect to a hydraulic system, heat-resistant temperature, dimensional stability, and compressive strength. It is preferable to use a material excellent in. Specifically, it is preferable that the heat resistant temperature is 400 ° C. or more and the compressive strength is 439 MPa or more when perpendicular to the layer and 98 MPa or more when parallel to the layer. By using such heat insulating members 18 and 28, the amount of deformation due to pressurization or heating of the heat insulating members 18 and 28 is suppressed, so that deterioration of the positional accuracy of the punch 13, die 14, and blank holder 20 is prevented. It becomes. Therefore, the workpiece W can be formed into a predetermined shape with high accuracy, and deterioration of the quality of the molded workpiece W can be prevented.

  Moreover, in the said embodiment, setting heating temperature shall be 300 degreeC, and the temperature of the workpiece | work W at the time of heating the workpiece | work W is shown in the position of Channels 1-5 as shown in FIG. 7, ie, each corner | angular part and center part of the workpiece | work W. As shown in FIG. 8, as shown in FIG. 8, at any position of Channels 1 to 5, the temperature reached 300 ° C. after 5 seconds from the start of heating, and then maintained at a constant temperature. In this way, heat is uniformly transmitted at the positions of Channels 1 to 5 and no temperature difference is caused by the respective positions, so that the quality of the workpiece W formed by the warm press forming apparatus 10 is prevented from being deteriorated. Can do.

It is a front view of the warm press molding apparatus which concerns on this Embodiment. It is the elements on larger scale of the warm press molding apparatus which concerns on this Embodiment. It is a top view of the punch and punch plate concerning this embodiment. It is a top view of the blank holder which concerns on this Embodiment. It is a top view of the die | dye which concerns on this Embodiment. It is a figure explaining the warm press molding method which concerns on this Embodiment. It is a figure which shows the temperature measurement position of a workpiece | work. It is a graph which shows the temperature measurement result of a workpiece | work.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Warm press molding apparatus 11 Lower mold 12 Upper mold 13 Punch 13a Outer wall surface 14 Die 14a Recessed part (receiving part)
14b Inner wall surface 18 Heat insulation member 19 Punch plate 20 Blank holder 25 Heater 28 Heat insulation member 29 Die plate 31 Heater

Claims (3)

In the warm press molding equipment that provides the upper mold so that it can be raised and lowered relative to the lower mold, and processes the workpiece with a punch and die,
A warm press molding characterized in that a plurality of heaters are embedded in a direction along the outer wall surface of the punch in a portion located around the punch, which is at least one of the lower die and the upper die. apparatus.     The warm press molding apparatus according to claim 1, wherein the heater is embedded in a blank holder having an opening and extending along an inner wall surface of the opening.     The warm press molding apparatus according to claim 1 or 2, wherein the heater is embedded in a die having a receiving portion for receiving the punch and along the inner wall surface of the receiving portion.

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