JP2013215750A - Method for forming metal sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a metal member, in which surface distortion and reduction in dimensional accuracy of a metal thin sheet to be subjected to incremental forming in the final step of forming can be made to the minimum.SOLUTION: A method for forming a metal sheet includes: press forming steps S110, S120, S130 of forming a workpiece W by press forming with a die; and an incremental forming step S150 of pressing a bar-shaped tool 10 against the workpiece W, gradually stretching the workpiece W while moving the same to form it into the final shape after the press forming steps S110, S120, S130. The incremental forming step S150 is regarded as the final step, and, in the incremental forming step S150, a bar-shaped tool 10 is pressed against the workpiece W, and the bar-shaped tool 10 is moved in such a manner that a stock margin moves from the planes 65, 66 with the final shape of the workpiece W toward the contour line 62 or the feature line 63 of the workpiece W in plan view.

Description

  The present invention relates to a technique of a metal plate forming method.

  The forming process of the metal plate is a process of deforming without removing a part of the metal plate (hereinafter, workpiece). As a method for forming a metal plate, for example, press forming using a mold is well known. Although press forming can be applied to mass production, it requires a large amount of money and time to manufacture the mold, and thus cannot be applied to small production.

  Incremental molding is known as a method for molding a workpiece that can be applied to small-scale production. Incremental molding is a molding method in which a rod-shaped tool is pressed against a workpiece without using a mold, and the workpiece is stretched little by little while moving the rod-shaped tool (for example, Patent Document 1).

  Incremental forming can handle a wide variety of products and small-scale production. However, for example, when forming from the flat plate to the final shape of the workpiece, the required tool path distance becomes long and the tool movement speed moves between minute points. There is a current situation where it takes time for molding and production efficiency is poor. In view of this, the inventors have proposed a metal plate forming method in which a workpiece is formed by press forming using a die and then formed by incremental forming in the final step.

  Incremental forming usually generates a workpiece material surplus. When the metal plate is processed only by the incremental forming process, the remainder of the material is formed so as to move to the edge side of the workpiece and can be removed in a subsequent process. However, when the work shape after the forming process by the press forming process is subjected to the incremental forming process, there is a possibility that surface distortion or a decrease in dimensional accuracy may occur in a portion where the remainder of the material is moved.

JP 2006-341262 A

  The problem to be solved by the present invention is to provide a metal plate forming method capable of minimizing surface distortion and dimensional accuracy degradation of a metal plate that is subjected to incremental forming in the final step of forming. is there.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, according to claim 1, there is provided a metal plate forming method, a press forming step of forming the metal plate by press forming using a mold, and after the press forming step, An incremental molding step of forming a final shape by pressing the metal plate and moving the metal plate little by little, and the incremental molding step is a final step. In the incremental molding step, the bar shape The tool is pressed against the metal member, and the bar tool is moved so that the remainder of the material moves from the plane area of the final shape of the metal plate toward the contour line or feature line of the metal plate in plan view. is there.

  In Claim 2, It is a shaping | molding processing method of the metal plate of Claim 1, Comprising: The said bar-shaped tool is pressed on the said metal plate, The said metal plate is continuously extended little by little, and it is made to separate from this metal plate. A tool path which is a trajectory of the bar-shaped tool is formed along a contour or feature line of the final shape of the metal plate, and a plurality of the tool paths are formed from the contour or feature line of the final shape of the metal plate. It is formed sequentially from a region located far away to a region located near the contour line or feature line of the final shape.

  According to a third aspect of the present invention, in the metal plate forming method according to the second aspect, the cross-sectional shape in the moving direction of the bar-shaped tool is gradually changed at the start point and the end point of the tool path.

  According to the metal plate forming method of the present invention, it is possible to minimize the surface distortion and the decrease in dimensional accuracy of the metal plate in which the incremental forming process is performed in the final step of the forming process.

The block diagram which showed the whole structure of the incremental shaping | molding processing apparatus which concerns on embodiment of this invention. The flowchart which shows the flow of a shaping | molding process similarly. Similarly schematic diagram. Sectional drawing which similarly shows the shape of a tool path.

The incremental molding apparatus 100 will be described with reference to FIG.
In addition, FIG. 1 represents the incremental shaping | molding processing apparatus 100 with the cross-sectional block diagram.

The configuration of the incremental molding apparatus 100 will be described.
The incremental forming apparatus 100 is a forming apparatus that presses the bar-shaped tool 10 against the work W and stretches the work W little by little while moving the bar-shaped tool 10. The incremental forming apparatus 100 includes a rod-shaped tool 10 and a support device 20.

  In addition, the workpiece | work W of this embodiment is taken as the components (fender 60 (refer FIG. 3)) of the motor vehicle processed from a metal plate. As will be described later, the workpiece W is formed by the incremental forming apparatus 100 at the final stage after being press formed by a press forming apparatus (not shown).

  The rod-shaped tool 10 is pressed against the workpiece W and stretches the workpiece W little by little while moving. The rod-shaped tool 10 is attached to an NC machine (not shown). An NC machine (Numerical Control machining) is a machine processing device by numerical control. In the NC machine, the operation of the bar-shaped tool 10 is defined by coordinate values in the X, Y, and Z directions, and the bar-shaped tool 10 is operated by the movement of a servo motor built in the machine tool based on the information. The molding process is performed.

  The support device 20 is a device that supports the workpiece W formed by the rod-shaped tool 10. The support device 20 includes a base 21, a buffer member 22, a backing plate 23, and a tightening jig 24.

  The base 21 is a portion on which the workpiece W is not formed (in this embodiment, the edge of the workpiece W) is placed. The buffer member 22 is disposed between the contact plate 23 and the workpiece W. The backing plate 23 presses a portion of the workpiece W that is not molded. The fastening jig 24 presses the backing plate 23 against a portion of the workpiece W that is not processed by fastening the base 21 and the backing plate 23.

The operation of the incremental molding apparatus 100 will be described.
The workpiece W is fixedly supported by the support device 20 at a portion that is not molded, and is stretched and molded by the bar-shaped tool 10 controlled by the NC machine.

The flow of the molding process S100 will be described with reference to FIG.
In addition, FIG. 2 represents the flow of shaping | molding process process S100 with a flowchart.

  The forming step S100 is an embodiment of the forming method of the present invention. The forming process S100 is a process for forming the workpiece W. The molding process S100 includes a plurality of press molding processes S110 to S130 and an incremental molding process S150. It is assumed that a cutting step S200, a machining step S300, and the like are performed after the forming step S100.

  Press molding process S110 * S120 * S130 is a process of press-molding the workpiece | work W with a pair of metal mold | die. The press forming process includes a bending process or a drawing process. In this embodiment, the first press molding process S110, the second press molding process S120, and the third press molding process S130 are provided as a plurality of press molding processes. It is not limited to.

  The incremental molding process S150 is a process in which the workpiece W is molded by the above-described incremental molding apparatus 100. The incremental forming step S150 is a step in which the bar-shaped tool 10 is pressed against the work W, and the work W is gradually stretched and formed while the bar-shaped tool 10 is moved.

  In the incremental molding process S150, not only the molding process that forms the workpiece W into the desired final shape in the molding process S100, but also the original shape of the shape molded in the multiple press molding processes S110 to S130. A molding process for restoring to (the shape before being molded) is also included.

  Here, it should be noted that the incremental molding process S150 is performed after the final process of the press molding process S110, that is, all the press molding processes S110 to S130 are completed.

The flow of the incremental molding process S150 will be described with reference to FIG.
FIG. 3 schematically shows the incremental molding process S150. A two-dot chain line in FIG. 3 represents a tool path of the rod-shaped tool 10.

  The incremental molding process S150 of the present embodiment is a process of molding the low-volume production type fender 60 based on the mass production type fender 50 molded in the plurality of press molding processes S110 to S130. The low-volume production type fender 60 is obtained by additionally processing an over fender 61 on the mass production type fender 50.

  In the press molding processing steps S110, S120, and S130, the mass production type fender 50 is molded by press molding using a mold.

  In the incremental molding process S <b> 150, the mass production fender 50 is molded into the small production fender 60. In the incremental forming step S150, first, forming is performed so as to form a flat surface 65 having the characteristic line 63 formed on the over fender 61 as one side. At this time, the rod-shaped tool 10 is moved so that the material remainder moves from the flat surface 65 of the overfender 61 in the final shape toward the feature line 63.

  The feature line 63 is a line indicating the structural feature of the workpiece W itself according to the shape of the workpiece W. For example, the characteristic line 63 is a boundary between the plane 65 and the plane 66 formed in the over fender 61.

  Further, the material surplus is an excess material after forming in the incremental forming step S150 in which the rod-shaped tool 10 is pressed against the workpiece W, and the workpiece W is moved and gradually stretched while the rod-shaped tool 10 is moved. is there.

  More specifically, the tool path is formed along the feature line 63 in the final shape of the workpiece W, and a plurality of tool paths are located far from the feature line 63 of the plane 65 in the final shape of the workpiece W. Then, the bar-shaped tool 10 is moved so as to be formed sequentially toward the region located near the feature line 63 on the plane 65 in the final shape.

  The tool path means that the bar-shaped tool 10 is pressed against the work W in the incremental forming step S150 in which the bar-shaped tool 10 is pressed against the work W, and the work W is moved and gradually stretched while being moved. This is the locus of the bar-shaped tool 10 on the workpiece W until it is separated from the workpiece.

  In the incremental forming step S150, next, the forming process is performed so that the flat surface 66 having the contour line 62 of the over fender 61 as one side is formed. At this time, the bar-shaped tool 10 is moved so that the material remainder moves from the flat surface 66 of the over fender 61 in the final shape toward the contour line 62.

  More specifically, a tool path is formed along the contour line 62 in the final shape of the workpiece W, and a plurality of tool paths are located far from the contour line 62 of the plane 66 in the final shape of the workpiece W. Then, the bar-shaped tool 10 is moved so as to be sequentially formed toward the plane 66 located close to the contour line 62 of the surface 66 in the final shape.

The cross-sectional shape of the tool path will be described with reference to FIG.
FIG. 4 shows a cross-sectional view in the moving direction of the bar-shaped tool 10 in the tool path.

  In the incremental forming step S150, the start point P1 and the end point P2 in one tool path, that is, when the bar-shaped tool 10 is pressed against the work W and when the bar-shaped tool 10 is separated from the work W, the moving direction of the bar-shaped tool 10 is changed. Molding is performed so that the cross-sectional shape is gradually changed.

  Note that the gradual change processing is to process by gradually changing the radius of the round in order to create a smooth shape where the workpiece W is usually rounded with a constant radius during processing.

The effect of the incremental molding process S150 will be described.
According to the incremental molding process S150, it is possible to minimize the surface distortion and the decrease in dimensional accuracy of the workpiece W in which the incremental molding process S150 is performed in the final process of the molding process S100.

  In other words, the surface distortion and dimensional accuracy of the workpiece W are reduced by forming the remainder of the material generated by the incremental forming process so as to move toward the feature line 63 or the contour line 62 that does not affect the surface distortion and dimensional accuracy. Can be minimized.

  Further, by forming so that the cross-sectional shape in the moving direction of the rod-shaped tool 10 is gradually changed at the start point P1 and the end point P2 in one tool path, the surface distortion and dimensional accuracy degradation of the workpiece W are minimized. be able to.

DESCRIPTION OF SYMBOLS 10 Bar-shaped tool 20 Support apparatus 50 Mass production type fender 60 Small production type fender 61 Over fender 62 Outline line 63 Feature line 65 Plane 66 Plane S100 Molding process S110 First press molding process S120 Second press molding process S130 Third press Molding process S150 Incremental molding process

Claims (3)

A metal plate forming method,
A press forming process for forming the metal plate by press forming with a mold;
After the press molding process, an incremental molding process in which a rod-shaped tool is pressed against the metal plate and is moved gradually while being moved to form a final shape.
Comprising
The incremental molding process is a final process,
In the incremental forming step, the bar-shaped tool is pressed against the metal member so that the material surplus moves from the plane area of the final shape of the metal plate toward the contour line or feature line of the metal plate in plan view. Moving the bar tool;
Metal plate forming method. It is a shaping | molding processing method of the metal plate of Claim 1, Comprising:
The tool path, which is the trajectory of the rod-shaped tool until the rod-shaped tool is pressed against the metal plate, the metal plate is continuously stretched little by little, and separated from the metal plate, is the contour line of the final shape of the metal plate or Formed along the feature line,
Further, a plurality of the tool paths are sequentially formed from a region located far from the contour line or feature line of the final shape of the metal plate toward a region located close to the contour line or feature line of the final shape. ,
Metal plate forming method. A metal plate forming method according to claim 2,
At the start point and end point of the tool path, the cross-sectional shape in the moving direction of the bar-shaped tool is gradually changed.
Metal plate forming method.

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