KR20010009065A - Apparatus and method for forming doubly-curved sheet - Google Patents

Abstract

PURPOSE: A device and a method for molding a board having a double curvature are provided to avoid the thickness deformation of the board by gradually pressing the board with a bending deformation principal in a state of not restricting the board and to obtain a natural shape of a surface waveform of the board. CONSTITUTION: A molding tool includes two pairs of support punches and a central punch(39). The two pairs of support punches(36) are installed on a punch support(37) to support and bend a board(35). The central punch bends the board by pressurizing from an upper part in a square frame formed by the two pairs of punches. Herein, the center of the board is pressed by using the support and central punches. The board is bend along back/forth and right/left directions around the center of the board. The board is bent in the outside direction from the center and symmetrically right and left around the center of the board. Then, an edge of the board is bent in order.

Description

Apparatus and method for forming doubly-curved sheet}

The present invention relates to an apparatus for forming a plate having a double curvature, and more particularly, to an apparatus for forming a plate having a double curvature by gradually pressing the plate using the bending deformation principle of the metal plate. The present invention also relates to a method of forming a sheet having a double curvature for forming a sheet using such an apparatus.

A description of the apparatus for forming curvature plates and the surface waviness according to the depth produced by striking the plates using such a device is described in `` Development of Incremental Sheet Metal Forming System Using Elastic Tools (Principle of Forming). Process and Formation of Some Fundamentally Curved Shapes) / M. Matsubara, S. Tanaka, and T. Nakamura / JSME International Journal Series C, Vol. 39, No. 1, 1996, pp. 156-163; Hereinafter, it is referred to as "quotation reference 1".

A brief description of the technical contents of Citation 1 is as follows.

As shown in FIGS. 1 and 2, the molding apparatus of Citation 1 has one die 12 supporting the plate 11 and the plate 11 fixed by the spring 17 on the X axis and Y. An XY axis table 13 for moving in the axial direction, a motor driver 14 for providing power for moving the XY axis table 13, and one punch for hitting the plate 11 to generate curvature. And a controller 16 for controlling the motor 14 and the punch 15.

Here, the plate 11 is made of a metal material that can be stretched or bent when the impact is applied, the die 12 is made of an elastic material that can absorb the impact, punch 15 ) Is made of steel with strength.

The molding apparatus configured as described above forms a sheet having a curvature by hitting the sheet 11 using the punch 15.

In addition, Citation 1 describes that there is a tendency for the surface wave to be constant due to the more stretch occurs as the depth hits.

That is, to summarize the contents of Citation 1 briefly, the molding apparatus forms the plate member 11 using one punch 15 and the die 12, and the basic principle is to hit the punch 15. In order to make the surface waveform of the board | plate material 11 constant, in other words, in order to smooth the surface of the board | plate material 11, the impact depth of the punch 15 must be deepened.

However, since the molding method of the plate member of the cited reference 1 is formed by stretching, there is a problem that the thickness deformation of the plate material occurs, and the thickness deformation of the plate material thus generated is irregular in some cases.

In addition, the contents of a molding apparatus for forming a sheet using stretch-expanding principles using CNC machine tools are described in `` Incremental Sheet Metal Stretch-Expanding with CNC Machine Tools / K. Kitazawa / Proceeding of the Fourth. '' International Conference on Technology of Plasticity, pp. 1899-1904; Hereinafter, it is referred to as "quotation 2".

A brief description of the technical contents of Citation 2 is as follows.

As shown in FIG. 3, the molding apparatus of Citation 2 fixes the curvature by fixing both ends of the metal plate 21 with a blank holder 22 and pressing the metal plate 21 using the punch 23. It is to shape a plate having.

However, the molding apparatus of the reference 2 is molded in a state in which both ends of the metal plate 21 is fixed with the blank holder 22, so that the fixing portion is not molded and unnecessary parts are formed based on the final shape. There is a problem that material loss occurs as much as the part fixed by the blank holder 22.

Therefore, the present invention has been made in order to solve the problems of the prior art as described above, by pressing the molding gradually in accordance with the principle of bending deformation of the plate without restraining the plate material is almost no thickness deformation of the plate forming It is an object of the present invention to provide an apparatus for forming a plate having a double curvature such that the surface waveform of the plate is naturally uniform.

1 is a schematic view for explaining the components of the apparatus for forming a plate having a double curvature according to the prior art,

Figure 2 is a perspective view showing the molding tool of the molding apparatus shown in Figure 1 separated;

Figure 3 is a schematic diagram showing a molding tool of the apparatus for forming a plate having a double curvature according to the prior art,

Figure 4 is a schematic diagram for explaining the components of the apparatus for forming a plate having a double curvature according to an embodiment of the present invention,

Figure 5a is a perspective view showing a separate molding tool of the molding apparatus shown in Figure 4,

5B is a perspective view showing a state where a plate is disposed between the molding tools shown in FIG. 5A,

6 is a process chart showing a process of molding a plate having a double curvature using the molding apparatus shown in FIG.

FIG. 7 is a conceptual diagram of forming an edge portion of a plate using the molding apparatus shown in FIG. 4.

8 is a process chart for explaining a molding path for molding a plate using the molding apparatus shown in FIG.

FIG. 9 is a perspective view of a plate having a double curvature formed by using the forming apparatus and the forming method shown in FIG. 4; FIG.

♠ Explanation of symbols on the main parts of the drawing ♠

31: fixed table 32: X axis table

33: Y axis table 34: Z axis table

35 metal plate 36 support punch

37: punch stand 38: control device

39: center punch

According to the present invention for achieving the above object, in the molding apparatus for bending a plate using a molding tool moving in the X-axis, Y-axis and Z-axis direction by the control of the control device, the molding tool is a punch pedestal It is composed of two pairs of support punches which are installed at and bent while supporting the sheet material, and a central punch which presses and bends the sheet material at the top in a rectangular frame formed by the two pairs of support punches.

In addition, according to the present invention, in a molding method for bending a plate using a molding tool moving in the X-axis, Y-axis and Z-axis direction under the control of a control device, using a pair of support punches and a center punch Pressing and bending the center of the plate, bending the front, rear, left, and right directions with respect to the center of the plate, sequentially bending the center from the center to the outside and symmetrically with respect to the center of the plate; The step of bending the edge of the plate sequentially.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the apparatus and the molding method for forming a plate having a double curvature according to the present invention will be described in detail.

4 is a schematic view for explaining the components of the apparatus for forming a plate having a double curvature according to an embodiment of the present invention, Figure 5a is a separate view showing the molding tool of the molding apparatus shown in FIG. 5B is a perspective view illustrating a state where a plate is disposed between the molding tools shown in FIG. 5A.

As shown in FIG. 4, the molding apparatus of the present invention includes a stationary table 31. Such a fixed table 31 is provided with a Y-axis table 33 moving in the Y-axis direction, and such a Y-axis table 33 is provided with a Z-axis table 34 moving in the Z-axis direction. The Z-axis table 34 is provided with an X-axis table 32 that moves in the X-axis direction. The X-axis, Y-axis, and Z-axis tables 32, 33, and 34 thus configured are operated by the driving force of each motor (not shown), and these motors are controlled by the controller 38, respectively.

5A and 5B, a punch pedestal 37 in which two pairs of support punches 36 for supporting the metal plate 35 to be molded are coupled to the X-axis table 32 is fixed. have. The support punch 36 coupled to the punch pedestal 37 is composed of two punches, and a quadrangle is formed by a total of four punches coupled to the punch pedestal 37. The ends of these four punches are formed to be round so that the metal plate 35 can be bent naturally.

The two pairs of support punches 36 thus coupled are installed to be moved back, front, left, and right with respect to the punch pedestal 37. That is, by moving the two pairs of support punches 36 in front, rear, left and right, the size of the quadrangle formed by the two pairs of support punches 36 is adjusted. The size of the rectangle is to control how much the plate bends.

As shown in FIG. 4, a central punch 39 used to bend the metal plate 35 placed on top of the pair of support punches 36 is fixed to the top of the fixed table 31. The end of the center punch 39 is formed to be round so that the metal plate 35 can be bent naturally.

Hereinafter will be described in detail the operation of the molding apparatus of the present invention configured as described above.

In the drawing, Figure 6 is a process chart showing a process of forming a plate having a double curvature using the molding apparatus shown in Figure 4, Figure 7 is used to mold the edge portion of the plate using the molding apparatus shown in FIG. It is a conceptual diagram.

First, as shown in FIG. 4, the metal plate 35 to be molded is placed on top of the pair of support punches 36, and the dimension of the depth to be bent in one operation is input to the control device 38. Start work afterwards. Then, the X-axis and Z-axis tables 32 and 34 are moved so that the center punch 39 is located at the center of the quadrangle formed by the two pairs of support punches 36.

Then, as shown in FIG. 6, the Y-axis table 33 moves upward by the control of the control device 38 to move the metal plate 35 to a depth that the center punch 39 is bent in one operation. Press it. Then, the bending of the metal plate 35 is caused by a force acting between the support punch 36 and the center punch 39.

In this way, when bending with respect to the said site | part is completed, under the control of the control apparatus 38, the Y-axis table 33 will return to a home position. Then, the metal plate 35 is manually moved to position the portion to be molded at the center of the quadrangle of the two pairs of support punches 36. At this time, a separate device may be attached to automatically place the metal plate 35 at the center of the quadrangle of the two pairs of support punches 36.

When the molding part is set in this way, the bending operation is performed in the same manner as described above. In the case where the sheet 35 is formed to have a double curvature through this process, and the edge portion is to be molded, as shown in FIG. 7, only three punches of the two pairs of support punches 36 are used to form the metal sheet 35. ), And the position of the center punch 39 is also adjusted over the center of the triangle formed by the three punches supporting the metal plate material 35 to form the metal plate material 35.

At this time, the center of the center punch 39 is adjusted by the movement of the X-axis and Z-axis tables 32 and 34 by the control device 38. When the edge portion of the metal plate 35 is molded, it is pressurized by about 2/3 of the depth at the time of forming on the center portion.

When the front surface of the metal plate 35 is bent once according to the above series of processes, the same process is continuously performed to bend a sheet having a double curvature by bending the desired depth.

Although the molding apparatus of the present invention described above forms the metal plate 35 by operating the Y-axis table 33 up and down, the Y-axis table 33 is fixed and the metal punch member is operated by operating the central punch 39 up and down. (35) can also be molded.

Hereinafter, the molding method of the plate using the molding apparatus of the present invention will be described in detail.

In the drawings, FIG. 8 is a process chart for explaining a molding path for forming a plate using the molding apparatus shown in FIG. 4, and FIG. 9 shows a double curvature formed by using the molding apparatus and the molding method shown in FIG. It is a perspective view of the board | plate material which has.

As shown in FIG. 8, first, the center of the metal plate 35 is pressed and bent, followed by bending along the front, rear, left, and right directions with respect to the center of the metal plate 35. Then, the bending is performed sequentially from the center to the outward direction and symmetrically with respect to the center of the metal plate 35. Then, the edge portion of the metal plate 35 is bent sequentially.

When the front surface of the metal plate 35 is bent once according to the above series of processes, the same process is continuously performed to bend a sheet having a double curvature by bending the desired depth. Then, a plate having a double curvature as shown in FIG. 9 is molded.

As described in detail above, the apparatus for forming a plate having a double curvature of the present invention and a method of forming the same have almost no thickness deformation due to gradual pressing to form a bending deformation principle of the plate.

In addition, the apparatus for forming a sheet having a double curvature and the forming method of the present invention by forming the entire range up to the edge portion in the state that the sheet is not restrained not only does not lose the plate at all but also the distribution of the double curvature You can even out.

In addition, the apparatus for forming a sheet material having a double curvature of the present invention and the forming method is formed by bending a plurality of times without bending the desired depth to form a body of a car, ship, aircraft, etc. from a thin metal material It can be applied to molding metal plates of various thicknesses up to the formation of thick metal plates.

The technical idea of the apparatus for forming a plate having a double curvature and the molding method of the present invention has been described above with the accompanying drawings, but this is by way of example only and not intended to limit the present invention. .

In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (5)

In the molding apparatus for bending a sheet material using a molding tool moving in the X-axis, Y-axis and Z-axis direction by the control of the controller, The molding tool is installed on the punch pedestal 37 to support the sheet metal 35 and bends the pair of support punches 36 and the plate material 35 in a rectangular frame formed by the pair of support punches 36. Apparatus for forming a plate having a double curvature, characterized in that it comprises a central punch (39) for bending by pressing from the top. 2. The apparatus as claimed in claim 1, wherein the two pairs of support punches (36) are configured to be movable in the front, rear, left and right directions with respect to the punch pedestal (37). In the molding method for bending a sheet material using a molding tool moving in the X-axis, Y-axis and Z-axis direction by the control of the controller, Pressing and bending the center of the plate 35 using two pairs of support punches 36 and a center punch 39; Bending along the front, rear, left and right directions with respect to the center of the plate member 35; Sequentially bending symmetrically from the center to the outward direction and symmetrically with respect to the center of the plate member 35; Method for forming a plate having a double curvature, characterized in that it comprises the step of sequentially bending the edge of the plate (35). The method of claim 3, wherein the plate member 35 is formed by gradually pressing the bending deformation principle, and after bending the front surface of the plate member once, the same process is performed a plurality of times to bend the desired depth. Method for forming a plate having a double curvature, characterized in that. The method according to claim 3 or 4, wherein in forming the edge portion of the plate 35, the plate 35 is supported using only three punches of the two pairs of support punches 36, and the center punch is formed. A double curvature characterized in that 39 is pressed to a depth of about 2/3 of the time of forming on the center of the plate 35 at the center position of the triangle formed by the three punches supporting the plate 35. Method for forming a plate having a.