JP2008100241A - Press working method and press working apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a press working method and a press working apparatus by which the occurrence of cracks in the end parts to which stretch-flanging is applied is prevented. <P>SOLUTION: In the press working apparatus, a steel sheet 12 is held with a holder 40 and blank holders 54 and, in the state where blank holding force is applied to the steel sheet, a potion of the steel sheet 12 is press-formed by lowering a fixed upper die 41. Next, in the state where the blank holding force applying to the steel sheet 12 is released by lowering the blank holders 54, a bent part is formed by performing the stretch-flanging of the rest portion of the steel sheet 12 by lowering a second upper die 90. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a press processing method and a press processing apparatus. Specifically, the present invention relates to a press processing method and a press processing apparatus for a molded product having an end portion that is stretch-flange-molded.

Conventionally, for example, an outer panel of a vehicle is formed by press-molding a thin plate-like workpiece (see Patent Document 1). According to the pressing method and the pressing apparatus disclosed in Patent Document 1, the end portion of the workpiece is clamped by the blank holder, and a wrinkle pressing force is applied to the workpiece. Next, the upper die is lowered and the workpiece is pressed by pressing the workpiece with the upper die and the lower die.
Japanese Unexamined Patent Publication No. 63-194826

  By the way, among the outer panels of the above-described vehicle, for example, a flange portion into which a door is fitted has a portion formed in a corner shape. However, since the portion formed in such a corner shape is formed by extending and molding a workpiece by flange, tensile stress concentrates during press molding, and the molded product may be cracked.

  An object of this invention is to provide the press work method and press work apparatus which can prevent that a crack arises in the edge part stretch-flange-molded.

  The press working method according to the present invention is a first press step in which a part of the workpiece is press-molded in a state in which a wrinkle holding force is applied to the workpiece in a press working method of a molded product having an end portion to be stretch flanged. And a second pressing step in which the remaining portion of the work is stretched and flanged to form the end in a state where the wrinkle holding force is released.

According to the present invention, in the second pressing step, the wrinkle holding force is released, so that the material can easily flow between the molds. In such a state, the work is stretched and flange-formed to form the end of the molded product, thereby preventing the end of the molded product from being cracked due to insufficient material.
Further, in the first pressing step, wrinkles can be prevented from occurring in a portion adjacent to the end portion by press-molding a portion other than the end portion prior to the end portion.

  In this case, in the second pressing step, it is preferable that the remaining part of the work is stretched and flange-formed while maintaining a state where a part of the work is pressed. Thereby, it can prevent reliably that a wrinkle arises in the part adjacent to an edge part.

  The press working apparatus according to the present invention is a press working apparatus that presses a molded product having an end portion that is stretch-flange-molded. The first mold and the second mold that are disposed with a workpiece interposed therebetween, and the first mold An advancing / retreating mechanism for advancing and retreating the mold of the mold with respect to the second mold, a holder for holding a workpiece, and a control means for controlling the advancing / retreating mechanism and the holder, wherein the first mold has a plurality of divisions The mold is divided into molds, and the control means press-molds a part of the workpiece using at least one of the plurality of divided molds in a state where the workpiece is sandwiched, and then in a state where the workpiece is not sandwiched. The remaining part of the workpiece is stretched and flange-molded using the remainder of the plurality of split molds to form the end part.

According to the present invention, the material is easily flown between the molds by releasing the wrinkle holding force applied to the workpiece without holding the workpiece with the holder. In such a state, it is possible to prevent the molded product from being cracked due to insufficient material by forming the end portion of the molded product by stretching the workpiece and forming the flange.
Further, by press-molding a portion other than the end portion prior to the end portion to be stretch-flange-molded, wrinkles can be prevented from occurring in a portion adjacent to the end portion.

  In this case, when forming the end portion, the control means maintains the state in which the workpiece is pressed with at least one of the plurality of divided molds, while remaining in the plurality of divided molds. It is preferable that the remaining part of the workpiece is stretched and flange-molded by using. Thereby, it can prevent reliably that a wrinkle arises in the part adjacent to an edge part.

According to the press processing method and the press processing apparatus according to the present invention, in the second pressing step, the wrinkle pressing force is released so that the material easily flows into the mold. In such a state, it is possible to prevent the molded product from being cracked due to insufficient material by forming the end portion of the molded product by stretching the workpiece and forming the flange. Further, by press-molding a portion other than the end portion prior to the end portion to be stretch-flange-molded, wrinkles can be prevented from occurring in a portion adjacent to the end portion.
Further, in the second pressing step, while maintaining a state in which a part of the work is pressed, the remaining part of the work is stretch-flange-molded to ensure that wrinkles occur in the part adjacent to the end of the molded product. Can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing a configuration of a rear side outer panel 80 of a vehicle press-molded by a press working apparatus according to an embodiment of the present invention.
The rear side outer panel 80 is made of a single steel plate, and includes a substantially flat panel body 81 and a flange portion 83 into which a vehicle door (not shown) is fitted.
The panel body 81 is divided into upper and lower parts in FIG. 1 as a panel upper part 811 and a panel lower part 812 with a character line 813 formed by bending a steel plate as a boundary.

  The flange portion 83 is provided on the left side of the panel upper portion 811 and the panel lower portion 812 in FIG. The flange portion 83 is formed by bending an end portion of a steel plate and extends in the vertical direction in FIG. Further, in the flange portion 83, the corner portion adjacent to the panel upper portion 811 is a curved portion (end portion) 831 formed by stretching and forming a steel plate by flange.

  FIG. 2 is a schematic diagram showing a partial configuration of the press working apparatus 10 according to the embodiment of the present invention. Specifically, FIG. 2 is a cross-sectional view taken along line AA of the rear side outer panel 80 shown in FIG.

  The press working apparatus 10 includes a lower mold mechanism 20 having a lower mold (second mold) 52 disposed below the steel plate (workpiece) 12, and a first upper mold (first mold) with respect to the lower mold 52. ) A first upper mold mechanism (advancing / retracting mechanism) 18 that makes the 38 approach and isolate, and a second upper mold mechanism 22 that is provided in the first upper mold 38 and that makes the second upper mold 90 approach and isolate the lower mold 52. And a control unit (control means) 16 for controlling the lower mold mechanism 20, the first upper mold mechanism 18, and the second upper mold mechanism 22.

  The mold surfaces of the first upper mold 38 and the second upper mold 90 of the press working apparatus 10 described above are formed corresponding to the panel body 81 and the flange portion 83 of the rear side outer panel 80, respectively. That is, the mold surfaces of the first upper mold 38 and the second upper mold 90 constitute one molding surface.

  The first upper mold mechanism 18 includes a servo motor 24, a rotating plate 28 that is rotationally driven by the servo motor 24 via a reduction gear (not shown), and an axial support that allows the upper end of the rotating plate 28 to swing on the side surface. Connecting rod 30.

  The servo motor 24 is, for example, an AC type, and has high responsiveness and small torque unevenness. The shaft rotation position of the servo motor 24 is detected by an encoder (not shown), and the servo motor is feedback-controlled based on the detected shaft rotation position.

  The first upper mold mechanism 18 further detects the position of the slider 32 pivotally supported on the lower end of the connecting rod 30, a guide (not shown) for guiding the slider 32 in the vertical direction, and detects the position of the slider 32. A first linear sensor 36 for supplying a signal and a first upper mold 38 provided on the lower surface of the slider 32 are provided.

  The first upper mold 38 includes a fixed upper mold 41 fixed to the slider 32 and an annular holder 40 provided around the fixed upper mold 41.

  The fixed upper die 41 is pressed by sandwiching the steel plate 12 together with the lower die 52, and a die surface 41a for contacting the upper surface of the steel plate 12 is provided on the lower surface. The holder 40 is provided so as to protrude downward from the mold surface 41a, and comes into contact with the steel plate 12 in advance of the mold surface 41a. The front end surface of the holder 40 is set to a horizontal plane.

Although not shown, the first upper die 38 is provided with a movable upper die mechanism (not shown) that moves the movable upper die (not shown) forward and backward with respect to the lower die 52. Further, this movable upper mold mechanism has a configuration substantially the same as the second upper mold mechanism 22 to be described in detail later with reference to FIG. 3, so that the mold surface of the movable upper mold is buried from the mold surface 41 a of the fixed upper mold 41. Or can be flush with the mold surface 41a.
The mold surfaces of the fixed upper mold 41 and the movable upper mold are formed corresponding to the panel upper part 811 and the panel lower part 812 of the panel body 81, respectively.

FIG. 3 is a cross-sectional view showing the configuration of the second upper mold mechanism 22 provided in the first upper mold 38.
As shown in FIG. 3, the second upper mold mechanism 22 includes a second upper mold 90 having a mold surface 90 a formed on the tip side, and the second upper mold 90 is buried from the mold surface 41 a of the fixed upper mold 41. A spring 91 that biases in the direction, an actuator 93 that makes the mold surface 90a of the second upper mold 90 flush with the mold surface 41a of the fixed upper mold 41, and the mold surface 90a and the mold surface 41a are flush with each other. And a mechanical lock 94 that locks the second upper mold 90.

  The second upper mold 90 is fitted in a guide hole 38b provided in the first upper mold 38, and can advance and retreat in the vertical direction in FIG. 3, for example. An inclined surface 90 b is formed on the base end side of the second upper mold 90.

  The actuator 93 includes a driver rod 92 that can advance and retreat in the left-right direction in FIG. 3, and an inclined surface 92 b that slides on the inclined surface 90 b of the second upper mold 90 is formed on the tip side of the driver rod 92. . The actuator 93 pushes the driver rod 92 rightward in FIG. 3, thereby pressing the inclined surface 90b of the second upper mold 90 and pushing out the second upper mold 90 downward in FIG. Thereby, the mold surface 90a of the second upper mold 90 is flush with the mold surface 41a of the fixed upper mold 41 (the same curved surface when the mold surface 41a is curved).

  The mechanical lock 94 advances and retreats in a direction (vertical direction in FIG. 3) perpendicular to the advancing and retreating direction of the driver rod 92 under the action of a predetermined pushing actuator (not shown). The driver rod 92 is formed with a notch 92a, and the mechanical lock 94 locks the driver rod 92 by fitting into the notch 92a of the pushed driver rod 92.

In the second upper mold mechanism 22 described above, the mold surface 90a of the second upper mold 90 is flush with the mold surface 41a of the fixed upper mold 41 in the following procedure.
That is, the driver rod 92 is pushed out in the right direction in FIG. Then, the driver rod 92 presses the inclined surface 90 b of the second upper mold 90 and pushes it downward in FIG. 3 against the elastic force of the spring 91. When the mold surface 90a of the second upper mold 90 is flush with the mold surface 41a of the fixed upper mold 41, the notch 92a of the driver rod 92 is located immediately below the mechanical lock 94 in FIG. Then, the tip of the mechanical lock 94 is fitted into the notch 92 a of the driver rod 92. Thereby, the second upper mold 90 is locked in a state where the mold surface 90 a is flush with the mold surface 41 a of the fixed upper mold 41.

In the second upper mold mechanism 22, the mold surface 90 a of the second upper mold 90 is buried from the mold surface 41 a of the fixed upper mold 41 in the following procedure.
That is, the lock by the mechanical lock 94 is released, and the bias of the driver rod 92 by the actuator 93 is released. Then, the second upper mold 90 receives a force in a direction to retract into the guide hole 38b by the elastic force of the spring 91, and presses the driver rod 92 to the left in FIG. The driver rod 92 moves until the convex portion 92c provided on the tip side thereof comes into contact with the stepped portion 38c formed in the first upper mold 38. As a result, the mold surface 90 a of the second upper mold 90 is buried from the mold surface 41 a of the fixed upper mold 41.

  Returning to FIG. 2, the lower mold mechanism 20 includes a fixed base 50 serving as a base, a lower mold 52 provided on the upper part of the fixed base 50, an annular blank holder 54 that supports the periphery of the steel plate 12, And a die cushion mechanism 56 for raising and lowering the blank holder 54.

  The lower die 52 is pressed with the steel plate 12 sandwiched with the fixed upper die 41, the second upper die 90, and the movable upper die (not shown), and comes into contact with the lower surface of the steel plate 12 on the upper surface. A mold surface 52a is provided. The mold surface 52a is formed in a shape corresponding to the mold surface 41a of the fixed upper mold 41, the mold surface 90a of the second upper mold 90, and the mold surface (not shown) of the movable upper mold.

  The blank holder 54 is provided at a position facing the holder 40 of the first upper die 38, and in order to prevent wrinkles and misalignment when the steel plate 12 is pressed, the blank holder 54 together with the holder 40 is an end portion of the steel plate 12. Pinch.

  The die cushion mechanism 56 includes, from below, a plurality of pins 60 that pass through the fixing base 50 and the attachment portion 52b of the lower mold 52 and are fixed to the lower portion of the blank holder 54, and plates connected to the lower ends of these pins 60 62, a hydraulic lifting mechanism 70 that lifts and lowers the plate 62, and a second linear sensor 72 that detects the position of the plate 62 and supplies a signal to the control unit 16.

  The elevating mechanism 70 includes a hydraulic cylinder (not shown) connected to the plate 62 and a servo device (not shown) that drives the hydraulic cylinder. This servo device is connected to the control unit 16, thereby pressing the peripheral portion of the steel plate 12 with an appropriate pressure by the blank holder 54 together with the holder 40 of the first upper mold 38 while performing predetermined pressure control. You can hold down wrinkles.

  The control unit 16 includes a first upper mold drive unit 16 a that drives the first upper mold mechanism 18, a second upper mold drive unit 16 b that drives the second upper mold mechanism 22, and a die cushion that drives the die cushion mechanism 56. And a drive unit 16c.

The second upper mold drive unit 16b drives and controls the actuator 93 and the mechanical lock 94 to push out the second upper mold 90 or lock the second upper mold 90.
The first upper mold drive unit 16 a drives and controls the servo motor 24 while referring to an encoder connected to the servo motor 24 and a signal supplied from the first linear sensor 36, and moves the slider 32 together with the first upper mold 38. To do. The first upper mold drive unit 16a is connected to a movable upper mold mechanism (not shown), and drives and controls the movable upper mold in the same manner as the second upper mold drive unit 16b.
The die cushion drive unit 16 c controls the servo device of the die cushion mechanism 56 while referring to the signal supplied from the second linear sensor 72 and moves the blank holder 54 up and down.

  Next, a method of forming the rear side outer panel 80 of the vehicle as shown in FIG. 1 by processing the steel plate 12 as a workpiece using the press working apparatus 10 configured as described above will be described with reference to FIGS. This will be described with reference to a flowchart.

  First, in step S1, initial setting is performed. That is, the blank holder 54 is raised to a predetermined position, and the blank steel plate 12 is supported by the blank holder 54. Here, the second upper mold 90 of the second upper mold mechanism 22 and the movable upper mold of the first upper mold 38 are buried and fixed from the mold surface 41a of the fixed upper mold 41 of the first upper mold 38. The upper mold 41 is raised to the top dead center.

  In step S2 (first pressing step), the servo motor 24 is rotationally driven to lower the fixed upper die 41 under the action of the first upper die driving unit 16a.

  When lowered to some extent, the holder 40 comes into contact with the upper surface of the steel plate 12, and the steel plate 12 is held between the holder 40 and the blank holder 54. Thereby, wrinkle pressing force is applied to the steel plate 12. Further, from this time (the time when the steel plate 12 is sandwiched between the holder 40 and the blank holder 54), the blank holder 54 is lowered under the action of the die cushion drive unit 16c (step S3).

  Here, the first upper mold drive unit 16a and the die cushion drive unit 16c are lowered while generating an appropriate force so that the blank holder 54 makes the lower surface of the steel plate 12 press and hold the steel plate 12 securely. Control the pressure as follows. That is, the blank holder 54 is pressed through the steel plate 12 by the holder 40 and is pressed down while applying an appropriate pressure to the steel plate 12. That is, the steel plate 12 is lowered in a state where the wrinkle pressing force is applied.

  In step S4 (first pressing step), the first upper mold drive unit 16a refers to the signal from the first linear sensor 36 to confirm whether or not the fixed upper mold 41 has reached the bottom dead center. When the fixed upper die 41 reaches the bottom dead center, the process proceeds to step S5, and when it does not reach, the descent continues.

  In step S5 (first pressing step), the lowering of the fixed upper mold 41 and the blank holder 54 is stopped. At this time, as shown in FIG. 6, the steel plate 12 is press-molded by being sandwiched between the mold surface 41 a of the fixed upper mold 41 and the mold surface 52 a of the lower mold 52. Thereby, the panel upper part 811 of the rear side outer panel 80 of FIG. 1 is formed.

  Here, the steel plate 12 is sandwiched between the holder 40 and the blank holder 54. Therefore, this panel upper part 811 is formed by press-molding a part of this steel plate 12 in a state where a wrinkle holding force is applied to the steel plate 12.

  In step S6, the first upper mold drive unit 16a drives an actuator of a movable upper mold mechanism (not shown) to push out the movable upper mold so that the mold surface of the movable upper mold faces the mold surface 41a of the fixed upper mold 41. Make it one.

  In step S7, the first upper mold driving unit 16a drives a mechanical lock of a movable upper mold mechanism (not shown) to lock the movable upper mold. At this time, the steel plate 12 is press-molded by being sandwiched between the mold surface 41 a of the fixed upper mold 41 and the mold surface of the movable upper mold and the mold surface 52 a of the lower mold 52. Thereby, the panel lower part 812 of the rear side outer panel 80 of FIG. 1 is formed.

  In step S8 (second pressing step), the die cushion drive unit 16c lowers the blank holder 54 to the bottom dead center. Thereby, the wrinkle pressing force applied to the steel plate 12 is released.

  In step S9 (second pressing step), the second upper mold driving unit 16b drives the actuator 93 to push out the second upper mold 90, and the mold surface 90a of the second upper mold 90 is moved to the fixed upper mold 41. It is flush with the mold surface 41a.

  In step S10 (second pressing step), the second upper mold drive unit 16b drives the mechanical lock 94 of the second upper mold mechanism 22 to lock the second upper mold 90. At this time, as shown in FIG. 7, the steel plate 12 includes a mold surface 41a of the fixed upper mold 41, a mold surface 90a of the second upper mold 90, a mold surface of the movable upper mold, and a mold surface 52a of the lower mold 52. And press-molded. Thereby, the flange part 83 of the rear side outer panel 80 of FIG. 1 is formed.

  Here, the blank holder 54 is separated from the steel plate 12. Therefore, the flange portion 83 is formed by press-molding the steel plate 12 in a state where the wrinkle pressing force is released. In particular, the curved portion 831 of the flange portion 83 is formed by extending and forming the steel plate 12 while maintaining the state where the panel upper portion 811 is pressed by the fixed upper die 41.

  In step S11, the first upper mold driving unit 16a drives the mechanical lock of the movable upper mold mechanism to unlock the movable upper mold. As a result, the mold surface of the movable upper mold is buried from the mold surface 41 a of the fixed upper mold 41.

  In step S <b> 12, the second upper mold driving unit 16 b drives the mechanical lock 94 of the second upper mold mechanism 22 to unlock the second upper mold 90. As a result, the mold surface 90 a of the second upper mold 90 is buried from the mold surface 41 a of the fixed upper mold 41.

  In step S <b> 13, the die cushion driving unit 16 c raises the blank holder 54 and sandwiches the processed steel plate 12 together with the holder 40.

  In step S14, under the action of the first upper mold drive unit 16a, the servo motor 24 is rotationally driven to raise the fixed upper mold 41.

  In step S15, the servo device of the die cushion mechanism 56 is controlled under the action of the die cushion drive unit 16c to raise the blank holder 54 to the panel transport position.

  In step S16, the pressed steel plate 12 placed on the blank holder 54 is transported to the next process station by a predetermined transport means.

  In step S <b> 17, the die cushion drive unit 16 c raises the blank holder 54 again to the processing standby position, and places the unprocessed steel plate 12 at a predetermined position. During this time, the fixed upper mold 41 continues to rise.

  In step S <b> 18, the first upper mold drive unit 16 a refers to the signal of the first linear sensor 36 and confirms whether or not the position of the fixed upper mold 41 has reached the top dead center. When the fixed upper die 41 has not reached the top dead center, the ascent is continued, and when the top dead center is reached, the processing of the steel plate 12 is finished.

  The press processing procedure using the press processing apparatus 10 has been described on one flowchart. For example, each of the first upper mold drive unit 16a, the second upper mold drive unit 16b, and the die cushion drive unit 16c is shown. The drive units may operate independently while mutually confirming synchronization.

According to the present embodiment, there are the following effects.
(1) According to the press processing method and press processing apparatus in the present embodiment, in the second press step, the blank holder 54 is lowered to release the wrinkle holding force, so that the material is the second upper mold 90 and It is set in a state in which it easily flows into the lower mold 52. In such a state, the steel plate 12 is stretched and flange-formed to form the curved portion 831 of the molded product, thereby preventing the molded product (rear side outer panel 80) from being cracked due to insufficient material. Further, by pressing the panel upper part 811 and the panel lower part 812 prior to the curved part 831 to be stretch-flange-formed, wrinkles can be prevented from occurring in the panel upper part 811 adjacent to the curved part 831.
(2) In the second pressing step, the remaining portion of the steel plate 12 is stretched and flange-formed while maintaining the state in which the panel upper portion 811 formed in the first pressing step is pressed by the fixed upper die 41, thereby forming the rear side. In the outer panel 80, wrinkles can be reliably prevented from occurring in the panel upper portion 811 adjacent to the curved portion 831.

Next, a second embodiment of the present invention will be described with reference to FIGS.
In the following description of the second embodiment, the same constituent elements as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.
FIG. 8 is a schematic diagram showing a partial configuration of a press working apparatus 10A according to the second embodiment of the present invention. Specifically, FIG. 8 is a cross-sectional view taken along line AA of the rear side outer panel 80 shown in FIG.

  In the press working apparatus 10A of the second embodiment, the configurations of the first upper mold mechanism 18A, the second upper mold mechanism 22A, and the control unit 17 are different from the press working apparatus 10 of the first embodiment.

  The press working apparatus 10A includes a lower mold mechanism 20 having a lower mold (second mold) 52 disposed on the lower side of a steel plate (workpiece) 12A, and a first upper mold (first mold) with respect to the lower mold 52. ) A first upper mold mechanism (advancing / retracting mechanism) 18A for approaching and isolating 38A, and a second upper mold mechanism 22A provided in the first upper mold 38A for allowing the second upper mold 90 to approach and isolate the lower mold 52. And a control unit (control means) 17 for controlling the lower mold mechanism 20, the first upper mold mechanism 18A, and the second upper mold mechanism 22A.

FIG. 9 is a cross-sectional view showing the configuration of the first upper mold 38A and the second upper mold mechanism 22A.
The first upper die 38 </ b> A includes a movable upper die 42 that is slidable in the vertical direction with respect to the slider 32, and an annular holder 40 that is provided around the movable upper die 42.

A plurality of gas springs 59 extending in the sliding direction of the movable upper mold 42 are interposed between the movable upper mold 42 and the slider 32.
These gas springs 59 constantly urge the movable upper mold 42 downward. 8 and 9 show a state in which these gas springs 59 are fully extended.

  Further, these gas springs 59 resist the pressing force from a state where the pressing force required for press forming the steel plate 12 is continuously applied to the mold surface 42a of the movable upper die 42. The upper movable mold 42 can be retracted to the position shown by the broken line in FIG. Further, in a state where the pressing force is not applied to the mold surface 42 a of the movable upper mold 42, the gas spring 59 is fully extended by the weight of the movable upper mold 42.

Although not shown, the first upper mold 38A is provided with a fixed upper mold fixed to the slider 32. The mold surface of the fixed upper mold is formed to be flush with the mold surface 42a of the movable upper mold 42 retracted upward.
Further, the mold surfaces of the movable upper mold 42 and the fixed upper mold are formed corresponding to the panel upper part 811 and the panel lower part 812 of the panel body 81, respectively.

Similarly to the first embodiment, the second upper mold mechanism 22A can advance and retract the second upper mold 90 in the vertical direction by the actuator 93, and can lock the second upper mold 90 by the mechanical lock 94. It has become.
FIG. 9 shows a state where the second upper mold 90 is retracted upward. Moreover, the 2nd upper mold | type 90 of the state extruded below is shown with the broken line in FIG. In this state, the mold surface 90a of the second upper mold 90 is flush with the mold surface 42a of the movable upper mold 42 in the retracted state (the same curved surface when the mold surface 42a is curved). Become.

  Next, a method of forming the rear side outer panel 80 of the vehicle as shown in FIG. 1 by processing the steel plate 12A as a workpiece using the press working apparatus 10A configured as described above will be described with reference to FIGS. This will be described with reference to a flowchart.

  First, in step S31, initial setting is performed. That is, the blank holder 54 is raised to a predetermined position, and the blank steel plate 12A is supported by the blank holder 54. Here, the second upper mold 90 of the second upper mold mechanism 22A is retracted upward, and the first upper mold 38A is raised to the top dead center.

  In step S32 (first pressing step), under the action of the first upper mold drive unit 17a, the servo motor 24 is rotationally driven to lower the first upper mold 38A.

  When lowered to some extent, the holder 40 comes into contact with the upper surface of the steel plate 12 </ b> A, and the steel plate 12 </ b> A is sandwiched between the holder 40 and the blank holder 54. Thereby, as shown in FIG. 12, wrinkle pressing force is applied to the steel plate 12A. Further, from this time (when the steel plate 12A is sandwiched between the holder 40 and the blank holder 54), the blank holder 54 is lowered under the action of the die cushion drive unit 17c (step S33).

  Here, the first upper mold drive unit 17a and the die cushion drive unit 17c are lowered while generating an appropriate force so that the blank holder 54 makes the lower surface of the steel plate 12A press and hold the steel plate 12A securely. Control the pressure as follows. That is, the blank holder 54 is pressed through the steel plate 12A by the holder 40 and is pressed down while applying an appropriate pressure to the steel plate 12A. That is, the steel plate 12A descends in a state where the wrinkle pressing force is applied.

  In step S34 (first pressing step), the first upper mold drive unit 17a refers to the signal from the first linear sensor 36 and confirms whether or not the first upper mold 38A has reached the bottom dead center. . When the first upper mold 38A has reached the bottom dead center, the process proceeds to step S35, and when it has not reached, the descent continues. Here, the bottom dead center of the first upper mold 38A is the position of the first upper mold 38A in a state where the movable upper mold 42 is retracted upward by lowering the first upper mold 38A. That is, when the first upper die 38A reaches the bottom dead center, the mold surfaces of the movable upper die 42 and the fixed upper die are in close contact with the steel plate 12A.

  Here, while the first upper mold 38A is lowered to its bottom dead center, a pressing force is continuously applied to the mold surface 42a of the movable upper mold 42. As a result, the movable upper mold 42 slides upward while the gas spring 59 is contracted.

  In step S35 (first pressing step), the lowering of the first upper mold 38A and the blank holder 54 is stopped. At this time, the mold surface 42a of the movable upper mold 42 and the mold surface of the fixed upper mold (not shown) are flush with each other, and as shown in FIG. It is sandwiched between the mold surface of the upper mold and the mold surface 52a of the lower mold 52 and press-molded. Thereby, the panel upper part 811 and the panel lower part 812 of the rear side outer panel 80 of FIG. 1 are formed.

  Here, the steel plate 12 </ b> A is sandwiched between the holder 40 and the blank holder 54. Therefore, the panel upper portion 811 and the panel lower portion 812 are formed by press-forming a part of the steel plate 12A in a state where a wrinkle holding force is applied to the steel plate 12A.

  In step S36 (second pressing step), the servo motor 24 is rotationally driven to raise the first upper die 38A under the action of the first upper die driver 17a.

  In step S37 (second pressing step), the first upper mold drive unit 17a refers to the signal from the first linear sensor 36 and determines whether or not the first upper mold 38A has reached the second upper mold preparation position. Confirm. When the first upper mold 38A has reached the second upper mold preparation position, the process proceeds to step S38, and when it has not reached, the ascent is continued. Here, the second upper mold preparation position is a position of the first upper mold 38A that can push the second upper mold 90 downward.

  In step S38 (second pressing step), the first upper mold drive unit 17a stops the rotation of the servo motor 24 and stops the first upper mold 38A at the second upper mold preparation position.

  In step S39 (second pressing step), the second upper mold drive unit 17b drives the actuator 93 of the second upper mold mechanism 22A to push the second upper mold 90 downward.

  In step S40 (second pressing step), the second upper mold drive unit 17b drives the mechanical lock 94 of the second upper mold mechanism 22A to lock the second upper mold 90.

  In step S41 (second pressing step), the die cushion drive unit 17c lowers the blank holder 54 to the bottom dead center. Thereby, the wrinkle pressing force applied to the steel plate 12A is released.

  In step S42 (second pressing step), the servo motor 24 is rotationally driven to lower the first upper die 38A under the action of the first upper die driver 17a.

  In step S43 (second pressing step), the first upper mold drive unit 17a refers to the signal from the first linear sensor 36 and confirms whether or not the first upper mold 38A has reached the bottom dead center. . If the first upper die 38A has reached the bottom dead center, the process proceeds to step S44, and if not reached, the descent continues.

  In step S44 (second pressing step), the first upper mold drive unit 17a stops the lowering of the first upper mold 38A. At this time, as shown in FIG. 14, the steel plate 12A includes a mold surface 42a of the movable upper mold 42, a mold surface 90a of the second upper mold 90, a mold surface of the fixed upper mold, and a mold surface 52a of the lower mold 52. And press-molded. Thereby, the flange part 83 of the rear side outer panel 80 of FIG. 1 is formed.

  Here, the blank holder 54 is separated from the steel plate 12A. Therefore, the flange portion 83 is formed by press-molding the steel plate 12A in a state where the wrinkle pressing force is released. In particular, the curved portion 831 of the flange portion 83 has the panel upper portion 811 as the movable upper die 42. The steel plate 12A is stretched and flange-formed while maintaining the pressed state.

  In step S45, the second upper mold drive unit 17b drives the mechanical lock 94 of the second upper mold mechanism 22A to unlock the second upper mold 90. Thereby, the second upper mold 90 is retracted upward.

  In step S <b> 46, the die cushion driving unit 16 c raises the blank holder 54 and sandwiches the processed steel plate 12 </ b> A together with the holder 40.

  In step S47, under the action of the first upper mold driver 17a, the servo motor 24 is rotationally driven to raise the first upper mold 38A.

  In step S48, under the action of the die cushion drive unit 17c, the servo device of the die cushion mechanism 56 is controlled to raise the blank holder 54 to the panel transport position.

  In step S49, the pressed steel plate 12A placed on the blank holder 54 is transported to the next process station by a predetermined transport means.

  In step S50, the die cushion drive unit 17c raises the blank holder 54 again to the processing standby position, and places the unprocessed steel plate 12A at a predetermined position. During this time, the first upper mold 38A continues to rise.

  In step S51, the first upper mold drive unit 17a refers to the signal of the first linear sensor 36 to check whether or not the position of the first upper mold 38A has reached the top dead center. When the first upper die 38A has not reached the top dead center, the ascent is continued, and when the first upper die 38A has reached the top dead center, the processing of the steel plate 12A is finished.

  The press working procedure using the press working apparatus 10A has been described on one flowchart. For example, each of the first upper mold driving unit 17a, the second upper mold driving unit 17b, and the die cushion driving unit 17c is illustrated. The drive units may operate independently while mutually confirming synchronization.

According to the second embodiment described above, there are the same effects as in the first embodiment described above.
It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.

It is a front view which shows the structure of the rear side outer panel of the vehicle press-molded by the press work apparatus which concerns on this Embodiment. It is a schematic diagram which shows the structure of the press work apparatus which concerns on this Embodiment. It is sectional drawing which shows the structure of a 2nd upper mold | type mechanism. It is a flowchart (the 1) which shows the procedure of the press work method which concerns on this Embodiment. It is a flowchart (the 2) which shows the procedure of the press work method which concerns on this Embodiment. It is a partial cross-section enlarged view of the press working apparatus in a state where the fixed upper die is lowered to the bottom dead center in a state where the second upper die is buried. It is a partial cross-sectional enlarged view of the press working apparatus in a state where the second upper mold is flush with the first upper mold and the fixed upper mold is lowered to the bottom dead center. It is a schematic diagram which shows the structure of the press work apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows the structure of a 1st upper mold | type mechanism and a 2nd upper mold | type mechanism. It is a flowchart (the 1) which shows the procedure of the press work method which concerns on 2nd Embodiment. It is a flowchart (the 2) which shows the procedure of the press work method which concerns on 2nd Embodiment. It is a partial cross section enlarged view of the press processing apparatus in the state which the holder of the 1st upper mold | type contacted the steel plate. It is a partial cross-section enlarged view of the press working apparatus in a state where the first upper mold is lowered to the bottom dead center with the second upper mold retracted upward. It is the partial cross section enlarged view of the press work apparatus in the state which lowered | hung the 1st upper type | mold to the bottom dead center in the state which extruded the type | mold surface of the 2nd upper type | mold downward.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10A ... Press processing apparatus 12,12A ... Steel 18,18A ... First upper mold mechanism 20 ... Lower mold mechanism 22,22A ... Second upper mold mechanism 32 ... Slider 38,38A ... First upper mold 41 ... Fixed upper Mold 41a: Fixed upper mold surface 42 ... Movable upper mold 42a ... Movable upper mold surface 40 ... Holder 52 ... Lower mold 52a ... Lower mold surface 54 ... Blank holder 56 ... Die cushion mechanism 80 ... Rear side outer panel 81 ... Panel body 811 ... Panel upper part 812 ... Panel lower part 83 ... Flange part 831 ... Curved part 90 ... Second upper mold 90a ... Mold surface of second upper mold

Claims (4)

In a method of pressing a molded product having an end that is stretch-flange molded,
A first pressing step of press-molding a part of the workpiece in a state in which a wrinkle holding force is applied to the workpiece;
A press working method comprising: a second pressing step in which the remaining portion of the work is stretched and flanged to form the end in a state where the wrinkle holding force is released. In the press processing method of Claim 1,
In the second pressing step, a press working method is characterized in that the remaining part of the work is stretched and flange-formed while maintaining a state where a part of the work is pressed. In a press working apparatus that presses a molded product having an end to be stretch flanged,
A first mold and a second mold arranged with a workpiece interposed therebetween;
An advancing and retracting mechanism for advancing and retracting the first mold with respect to the second mold;
A holder for clamping the workpiece;
Control means for controlling the advance / retreat mechanism and the holder,
The first mold is divided into a plurality of divided molds;
The control means press-molds a part of the workpiece using at least one of the plurality of division molds with the workpiece sandwiched, and then the plurality of divisions without clamping the workpiece. A press working apparatus, wherein the remaining part of the work is stretched and flange-molded using the remainder of the mold to form the end part. In the press processing apparatus of Claim 3,
When forming the end portion, the control means uses the remaining of the plurality of divided molds while maintaining the state in which the workpiece is pressed with at least one of the plurality of divided molds. A press working apparatus, wherein the remaining part of the work is stretched and flange-formed.

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