JPH09220622A - Deep drawing apparatus and deep drawing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the generation of friction heat at the peripheral part of a blank press-held between a die and a blank holder and to properly press- hold the blank. SOLUTION: In advance of a deep drawing action with a punch 9 by lowering the die 5, oil is supplied into a recessed part 15 so as to obtain a fixed pressure after sealing a preceding holder 29 with a sealing material 25 in contact with the blank W. After supplying the oil, at the time of lowering the die 5, a projecting part 27 presses the blank W and intrudes into the recessed part 15 while the preceding holder 29 intrudes into a sliding hole 31 against springs 33. The blank W is bend-deformed so as to be wound itself around the projecting part 27 by oil pressure to form a bead part, and a deep drawing is executed with the punch 9 while pushing down the blank holder 11 by further lowering the die 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a draw forming apparatus and a draw forming apparatus for drawing a blank material, the peripheral portion of which is pressed and sandwiched between a die and a blank holder, into the punch side by cooperation of the die and the punch. Regarding the method.

[0002]

SUMMARY OF THE INVENTION The present invention is a pressing pinching portion which is generated when a blank material whose peripheral edge portion is pressed and pinched between a die and a blank holder flows into the punch side in a drawing operation. It is intended to suppress the frictional heat of and to perform the pressing and clamping operation on the blank material as desired.

[0003]

In order to achieve the above-mentioned object, the present invention firstly cooperates with a die and a punch to form a blank material whose peripheral edge portion is pressed and sandwiched between the die and the blank holder. In the draw forming apparatus that draws and draws to the punch side by means of the drawing, the pressing surface located below the blank material between the die and the blank holder is provided with a concave portion to which the liquid to which a predetermined pressure is applied is supplied, and upward. The pressing surface located is provided with a convex portion that enters the concave portion while pressing the blank material against the pressure of the liquid.

Secondly, in the first structure, on the pressing surface around the convex portion, the tip end corresponds to the pressing surface on the concave portion side prior to the contact operation of the convex portion with the blank material in the drawing operation. A structure is provided in which a preceding pressing member is provided which comes into contact with the blank material and enters the pressing surface on the convex portion side while maintaining the contact state of the tip end with the drawing operation.

Thirdly, in the second construction, a sealing material is provided on the pressing surface around the concave portion facing the preceding pressing member so as to be in close contact with the blank material for sealing.

Fourthly, in a draw forming method for drawing a blank material whose peripheral portion is pressed and sandwiched between a die and a blank holder by drawing the blank material into the punch side in cooperation with the die and the punch, the die and the blank. A liquid having a predetermined pressure is supplied into a concave portion provided on a pressing surface located below the blank material between the holders, and a convex portion provided on the pressing surface located above is supplied to the blank before the drawing operation. This is a draw forming method in which a material is bent while being pressed into the concave portion against the pressure of the liquid.

[0007]

According to the first invention or the fourth invention,
When the convex part presses the blank material and enters the concave part,
The blank material is bent by hydraulic pressure between the convex part and
The peripheral edge portion of the blank material is pressed and sandwiched between the die and the blank holder around this bending-formed vicinity,
Since the pressing and pinching portion includes a portion that is in contact with the liquid, frictional heat generated when the blank material slides on the pressing and pinching portion and flows into the punch side is suppressed, and the pressing and pinching operation of the blank material is suppressed. It can be done as desired.

According to the second aspect of the invention, before the convex portion comes into contact with the blank material, the preceding press can press the blank material against the pressing surface to prevent the liquid in the concave portion from flowing out. Even if the pressing surface is inclined, it can be dealt with.

According to the third invention, the liquid in the recess can be more reliably prevented from flowing out by the sealing material.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a main part of a draw forming apparatus showing an embodiment of the present invention. This draw forming apparatus is for forming an outer panel of a trunk lid of an automobile. A lower die 1 as a whole is shown as a plan view in FIG. 2, and a die on the upper die 3 side along the line AA in FIG. 5
An enlarged cross-sectional view including the above is FIG. Die 5
Is fixed to an upper mold holder (not shown) and can move up and down with respect to the lower mold 1. In the lower die 1, a punch 9 is fixed to a lower die holder 7, and a blank holder 11 is elastically supported via a spring 13.

As shown in FIG. 1, a portion of the blank holder 11 corresponding to the rear side of the vehicle body taken along the line AA in FIG. 2 forms an inclined surface 11a whose upper surface serves as a pressing surface. A recess 15 extending in a direction perpendicular to the plane of the drawing in FIG. 1 is formed on 11a. One end of an oil passage 17 through which oil as a liquid flows communicates with the bottom surface of the recess 15, and the other end of the oil passage 17 opens to the outside of the blank holder 11 and is connected to an oil pump 21 via an oil pipe 19. It is connected. A groove 23 is formed in the inclined surface 11a of the blank holder 11 so as to surround the periphery of the recess 15, and a sealing material 25 is fitted in the groove 23.

On the other hand, in the die 5 on the upper die 3 side, the lower surface corresponding to the inclined surface 11a of the blank holder 11 forms an inclined surface 5a serving as a pressing surface, and the concave portion 15 on the inclined surface 5a is formed. A convex portion 27 is formed at the corresponding portion.
The convex portion 27 is inclined so that the lower end surface 27a is parallel to the inclined surface 5a, and the width (horizontal direction in FIG. 1) and length (FIG. 1).
(Direction orthogonal to the paper surface), height (vertical direction in Fig. 1)
All of the dimensions are smaller than the recess 15.

A leading presser 29 is provided on the inclined surface 5a of the die 5 at a position corresponding to the sealing material 25 so as to surround the convex portion 27. The preceding presser 29 is slidably accommodated in a sliding hole 31 formed in the die 5,
A spring 33 provided between the sliding hole 31 and the bottom.
The fixing block 35 is urged downward by and fixed to the lower surface of the die 5 to prevent the die 5 from coming off. The lower end surface 29a of the preceding presser 29 has the die 5
The inclined surface 5a and the lower end surface 27a of the convex portion 27 are inclined, and project downward from the lower end surface 27a of the convex portion 27. The elastic force of the spring 33 is set to be sufficiently weaker than the elastic force of the spring 13.

Next, the operation of the draw forming apparatus configured as described above will be described. First, when the die 5 of the upper die 3 is lowered with the plate-shaped blank material W set on the lower die 1 as shown in FIG. 1, as shown in FIG. The blank material W is contacted with the blank material W by the urging force of the spring 33 between the blank material W and the seal material 25.
Is held. In this state, the oil pump 21 is driven to fill the oil 37 in the concave portion 15 to keep the concave portion 15 at a constant pressure. At this time, since the periphery of the recess 15 is sealed by the sealing material 25, oil does not flow out.

When the die 5 is further lowered from the state shown in FIG. 3, as shown in FIG.
The convex portion 27 presses the blank material W into the concave portion 15 while entering into the sliding hole 31 against 3. At this time, the blank material W is bent and deformed by hydraulic pressure so as to be wound around the convex portion 27 to form the bead portion B, and at the same time, the inclined surface 5a of the die 5 adheres to the blank material W, whereby the blank material W is formed. The peripheral edge of W is pressed and sandwiched between the die 5 and the blank holder 11.

When the die 5 is further lowered from the state of FIG. 4, the die 5 holds the blank material W together with the blank holder 11 and pushes down the blank holder 11 against the spring 13, as shown in FIG. , Punch 9 and drawing are performed. At the time of this draw forming, the part of the blank material W held by the blank holder 11 and the die 5 flows into the punch 9 side with the draw forming, but this inflow operation causes the blank material W to wind around the convex portion 27. As a result, tension (restraint force) is generated and movement of the blank material W is controlled.

During the inflow movement of the blank material W to the punch 9 side, the blank material W is sandwiched by a portion having hydraulic pressure, and the die 5 and the blank holder 1 are provided.
Since the area (area) where the blank material W directly contacts and slides with respect to 1 is small, frictional heat is less generated, and the oil 37 prevents the die 5 and the blank holder 11 from sliding.
Since it is cooled, even when a plurality of blank materials are continuously subjected to the draw forming operation, it is hardly affected by the thermal expansion, and the clamping pressure between the die 5 and the blank holder 11 is properly adjusted. Reserved. As a result, the blank material W is prevented from cracking at a portion clamped by the die 5 and the blank holder 11 due to the clamping pressure being too high, and also flows into the punch 9 side too much due to the clamping pressure being too weak. Therefore, the draw forming operation can be performed with desired accuracy.

When supplying the oil 37 to the concave portion 15, the blank material W is applied to the seal material 2 by the preceding presser 29.
Since it is sandwiched between the die 5 and the blank holder 11,
Even if the pressing and sandwiching surface between and is the inclined surfaces 5a and 11a, it is possible to deal with the oil without leaking and the reliability is high. The oil 37 in the recess 15 is
By releasing the hydraulic pressure applied by the oil pump 21, the oil pump 21 is released to prepare for the next drawing operation.

The bead portion B of the blank W here
The force required to mold the is per unit length of the bead B in the longitudinal direction is 15 kg / mm (blank material W
However, since the thickness is up to about 1.0 mm (for thin plates up to 1.0 mm), it is sufficient to add a hydraulic pressure of 15 kg / mm or more. Further, in the above-described embodiment, the punch and the blank holder are provided in the lower mold, and the die is provided in the upper mold, respectively. On the contrary, the die is fixed to the lower mold, and the punch and the upper mold are provided. The present invention may be applied to a configuration in which the blank holder is provided so as to be relatively movable. In this case,
The lower die has a concave portion for supplying oil, and the upper die blank holder has a convex portion.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a draw forming apparatus showing an embodiment of the present invention.

FIG. 2 is a plan view of a lower die in the draw forming apparatus of FIG.

FIG. 3 is an operation explanatory view of the draw forming apparatus in FIG.

FIG. 4 is an operation explanatory view of the draw forming device in FIG. 1.

5A and 5B are operation explanatory views of the draw forming apparatus in FIG.

[Explanation of symbols]

 5 Die 5a, 11a Sloping surface (pressing surface) 9 Punch 11 Blank holder 15 Recessed portion 25 Sealing material 27 Convex portion 29 Preceding press W Blank material

Claims (4)

[Claims] 1. A draw forming apparatus for drawing a blank material, the peripheral edge portion of which is pressed and sandwiched between a die and a blank holder, to the punch side by cooperation of the die and the punch, to draw the blank material from each other. The pressing surface located below the blank material in between is provided with a recess to which the liquid to which a predetermined pressure is applied is supplied, and the pressing surface located above the blank material is pressed against the pressure of the liquid. A draw forming apparatus, characterized in that a convex portion that enters the concave portion is provided. 2. The pressing surface around the convex portion comes into contact with the blank material at a position corresponding to the pressing surface on the concave side prior to the contacting operation of the convex portion with the blank material in the drawing operation, and 2. The draw forming apparatus according to claim 1, further comprising a preceding pressing member which is inserted into the pressing surface on the convex portion side while maintaining the contact state by the tip end with the draw forming operation. 3. The draw forming apparatus according to claim 2, wherein a sealing material which is in close contact with the blank material and seals is provided on the pressing surface around the concave portion facing the preceding pressing member. 4. A draw forming method in which a blank material, the peripheral portion of which is pressed and sandwiched between a die and a blank holder, is drawn into the punch side by the cooperation of the die and the punch to draw the blank material, wherein the die and the blank holder are mutually In the recess provided in the pressing surface located below the blank material between,
By supplying a liquid to which a predetermined pressure is applied, the convex portion provided on the pressing surface located above is bent and formed while pushing the blank material into the concave portion against the pressure of the liquid prior to the drawing operation. Characteristic drawing method.