Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
  • B21D22/14—Spinning
  • B21D22/18—Spinning using tools guided to produce the required profile
  • B21D22/185—Spinning using tools guided to produce the required profile making domed objects
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
  • B21D22/14—Spinning

Definitions

• the invention relates to a drawing process of the type specified in the preamble of claim 1 and a device for workpiece machining in the drawing process of the type specified in the preamble of claim 7.
• a punching nibbler is also known from stamping technology, in which a clamped sheet metal is locally exposed to the action of a punching tool and a die tool, which create a small slot in the sheet metal.
• the sheet is moved by a path control in accordance with a predetermined punching contour in such a way that the slot is continuously lengthened. In this way, any workpiece contours can be punched out step by step, the punching out taking place in a single circulation of the sheet relative to the tools.
• the invention is based on the object of further developing the drawing method of the type specified in the preamble of patent claim 1 in such a way that no workpiece-specific form-bound tools are required for producing moldings, so that molds of different shape and size are produced with a pair of tools can be.
• the sheet metal is locally deformed by the relative stamp head moving to the drawing edge, the size of which is much smaller than that of the shape to be produced.
• the local machining can proceed along the workpiece contour to be produced, so that the drawing takes place with tools which only locally determine the geometry of the formation and are continued in many small steps.
• the stamping head can execute vibrations perpendicular to the workpiece, that is, in the direction of the formation to be produced, while the drawing edge is located to the side of the stamping head and the die tool supports the edge surrounding the formation.
• a special peculiarity of this pulling process is that the pulling cannot be carried out in a single step or in a single revolution.
• the method according to the invention is suitable for forming tabular workpieces, i.e. of workpieces made of sheet metal or another surface material, including plastic.
• the process can be carried out as a deep-drawing process or as a stretch-drawing process.
• the stamp path is limited in that the workpiece is overstressed if the path is too long.
• Such small movement amplitudes are generally not sufficient to produce the formation, so that the drawing process is carried out in several stages, in which the formation is increasingly being completed. These stages can either be carried out by deepening the formation between two successive revolutions, or by continuously deepening the formation by continuously lowering the stamp head so that a helical movement of the stamp head takes place.
• the shaping can also be carried out without a reciprocating movement of the stamp head, the stamp head and die tool being held relative to one another and the clamping frame being moved relative to these two parts.
• the contour control is expediently carried out by moving a clamping frame, in which the workpiece is clamped, in accordance with the shape of the shape to be produced in the clamping frame plane under the control of a contour control device.
• the punch head and, if applicable, the die tool are adjusted transversely to the clamping frame level in order to change the depth of the respective shaping step.
• it is also mög ⁇ Lich to arrange the clamping frame fixed and move the two tools with a 'contour control.
• the stenter can also perform the vertical movements. It is only important in any case that relative movements between the clamping frame and the two tools (punch head and die tool) are carried out to continuously change the machining location on the workpiece. If movements of the stamp head are carried out relative to the workpiece, the contour control ensures that the stamp head acts locally on two different positions of the workpiece during two successive movements.
• punch heads and die tools can be used in the method according to the invention, depending on the respective requirements, such as material thickness, material quality and contour of the shape to be produced, no special adaptation of the respective tools to the shape of the shape is required. It is therefore it is not necessary to manufacture tools that correspond specifically to the contour of the shape and are only suitable for such shape.
• the method is therefore particularly suitable for small series or for machining individual pieces, the workpiece contour to be produced merely having to be transferred to the control and the control then controlling a controlled machine tool which moves the clamping frame and the tools in such a way that the workpiece machining is carried out in numerous small steps in succession.
• the drawing process works with tools that only determine the workpiece geometry locally and carry out the workpiece machining in numerous small steps without changing tools.
• the method enables the production of drawn parts without the need for a product-specific tool.
• Fig. 1 is a schematic representation of the method and the components required for it, and
• FIGS. 2 and 3 r two stages of a multi-stage processing method
• the method shown in the drawings is a stretch-drawing method in which the workpiece edge is firmly clamped, but the invention is not restricted to this.
• the workpiece to be machined namely a flat sheet 10 made of metal
• a clamping frame 11 which has a lower part 12 and an upper part 13, which are pressed together so tightly, including the sheet metal edge, that the sheet metal material cannot flow out of the gap of the clamping frame.
• the clamping frame 11 can be moved in its plane in the X and Y directions under the control of a control device 14.
• a punch head 15 which forms the upper tool and has a ball head 16 in the exemplary embodiment described here, is arranged above the sheet metal 10 located in the clamping frame 11.
• the diameter of the ball head 16 is substantially smaller than the diameter of the shape of the sheet 10 to be produced.
• the punch head 15 is driven by an oscillating drive 17 in such a way that it can execute oscillating movements at right angles to the XY plane.
• the oscillating drive 17 is not absolutely necessary for the machining process, since the movement of the stamping head 15 can also be carried out exclusively by a non-oscillating drive device 18.
• the die tool 19 Arranged under the clamping frame 11 is the die tool 19, which has a protruding die element 20 with a rounded drawing edge 21.
• the matrix element 20 is fastened to a holder 22 so as to be displaceable in the direction of the double arrow 27, which can be pivoted about an axis 23 which is located in the axial direction with the punch head axis.
• the swivel drive is also controlled by the control unit 14 in accordance with a predetermined program, as is the height adjustment of the die tool 19 in the direction of the double arrow 27.
• the rounded drawing edge 21 has a straight course.
• a die element 20 can also be used, the drawing edge of which is curved.
• the drawing edge 21 is at a lateral distance from the axis 23, which is generally at least equal to the sheet thickness.
• Rotatable rollers can also be used as the punch head or as the die tool.
• the workpiece 10 with the stamp head 15 and the die tool 19 is firmly pre-stretched with its flange 25 in the clamping frame 11.
• the upper side of the die element 20 is placed against the workpiece and the punch head 15 is pulled during its vertical movement, the sheet 10 over the drawing edge 21, the clamping frame 11 being moved in the fixed XY coordinate system in such a way that the drawing gap is moved in accordance with the side contour of the formation to be formed.
• This means that the punch head 15 is moved along the inner envelope of the formation and the die tool 19 along the outer envelope of the formation (relative to the clamping frame 11). Numerous round trips, i.e. Revolutions, carried out, wherein only a further depth is formed in the sheet 10 during each revolution.
• Fig. 2 shows a state in which numerous revolutions have already taken place, the stamp head 15 being lowered further after each revolution or drawing step in order to carry out the next drawing step.
• the shape to be produced is rotationally symmetrical and that, for example, a bowl or bowl is to be produced.
• the vertical axis of the punch head 15 runs eccentrically to the clamping frame 11 and the clamping frame is rotated continuously, the drawing edge 21 always running tangentially to the shape.
• the shape does not have to be rotationally symmetrical. Rather, it can also be achieved by appropriate movement control of the clamping frame 11 that rectangular or other shapes are formed.
• the stamp head 15 being replaced by a stamp head 15a with a smaller working diameter and a smaller stamp edge radius and the die tool 19 being replaced by a die tool 19a having a working edge 21a having a smaller radius of curvature.
• the general rule states that the punch head and the drawing edge are initially used with relatively large radii of curvature and that, in the final machining, tools with ever smaller radii of curvature should be used.
• the stamp head 15a executes vertical movements, while the clamping frame 11 of the XY plane is moved in such a way that the entire circumferential surface of the workpiece extends the drawing gap between the stamping through the head and die tool.
• the machining shown in FIG. 3 can also extend over numerous rotations of the clamping frame 11.
• the force is introduced into the workpiece indirectly, i.e. elsewhere than the forming.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shaping Metal By Deep-Drawing, Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=6417378

Family Applications (1)

Country Status (2)

Cited By (3)

Families Citing this family (13)

Citations (6)

Family Cites Families (1)

• 1990
  • 1990-10-31 DE DE19904034625 patent/DE4034625A1/de active Granted
• 1991
  • 1991-10-30 WO PCT/EP1991/002053 patent/WO1992007672A1/de active Application Filing

Patent Citations (6)

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