JP6714854B2 - Sequential molding method - Google Patents

Description

The present invention relates to a sequential forming tool used for sequentially forming a metal plate into a three-dimensional shape by pressing and moving the tool against a metal plate holding the periphery, and a sequential forming using the sequential forming tool. It is about the method.

BACKGROUND ART Conventionally, as a sequential forming tool and a sequential forming method, there is one described in Patent Document 1. The sequential forming method described in Patent Document 1 uses a lower mold having a shape of a molded product, an outer peripheral frame that holds a metal plate on the upper surface side of the lower mold, and a forming tool that is movable in three orthogonal axial directions. .. Then, the sequential forming method, on the upper surface side of the lower mold, holds the periphery of the flat metal plate by the outer peripheral frame, presses the sequential forming tool against the metal plate to move the metal plate, and moves the metal plate along the outer peripheral frame. Drop around. As a result, the metal plate is gradually deformed so as to fit the lower mold, and finally a three-dimensional molded product is molded.

In addition, the successive forming tool described in Patent Document 1 has a resin pressing portion that is attachable and detachable at the tip portion. The resin pressing portion includes a spherical tip surface having a constant radius of curvature. The successive forming tool prevents the transfer of the scanning line of the tool on the metal plate by bringing the resin pressing portion into surface contact with the metal plate.

JP, 2002-102945, A

The diameter and the radius of curvature of the above-described successive forming tool are determined by the minimum radius of curvature of the formed product. However, since a tool with a small diameter has a small contact area with the metal plate, flaking is likely to occur in a portion having a large radius of curvature such as a linear region, and the pitch, which is the displacement width of the movement path, should be reduced. Since it is unavoidable, the processing time is correspondingly increased and the processing efficiency is reduced.

On the other hand, in the conventional successive forming tool, the resin pressing portion can suppress the occurrence of flaking to some extent. However, in the conventional successive forming tool, the resin pressing portion is heavily worn, it is necessary to frequently replace the resin pressing portion, and since the resin pressing portion has a constant radius of curvature, there is no problem that the pitch cannot be increased. It remained a solution. In addition, the conventional successive forming tool requires replacement of the tool in order to change the pitch.

The present invention has been made in view of the above-mentioned conventional situation, and it is possible to perform molding according to a part of a molded product with a single tool, and to set a pitch that is a displacement width of a moving path. An object of the present invention is to provide a sequential forming tool that can be increased in size to improve the processing efficiency and a sequential forming method using the same.

The successive forming tool according to the present invention is a rod-shaped tool used for sequentially forming a three-dimensional shape of a metal plate whose periphery is held. In this successive forming tool, an outer peripheral surface in a predetermined range from the tip end to the axial direction is used as a processing surface, and the processing surface is formed with contour lines having partially different radii of curvature in a cross section orthogonal to the axial direction. It is characterized by

A sequential forming method according to the present invention is a rod-shaped tool, wherein an outer peripheral surface in a predetermined range from a tip end to an axial direction is a processing surface, and the processing surface has a partial radius of curvature in a cross section orthogonal to the axial direction. Using the sequential forming tool formed with different contour lines, press the above sequential forming tool against the metal plate holding the periphery to move the predetermined movement path, and push in and move the sequential forming tool. This is a method of sequentially forming a metal plate into a three-dimensionally formed product by displacing the path stepwise. The sequential forming method is characterized in that the rotation angle around the axis of the sequential forming tool is selected according to the part of the formed product to perform the forming.

The successive forming tool according to the present invention adopts the above-mentioned configuration, so that the entire machined surface is smoothly continuous. In this sequential forming tool, by selecting a rotation angle around the axis with respect to the metal plate, the radius of curvature of the machined surface abutting on the metal plate differs depending on the rotation angle, and the contact area with the metal plate also differs. Will be things. As a result, the sequential forming tool can perform forming according to the part of the formed product, even though it is a single tool, and the pitch, which is the displacement width of the movement path, is increased to improve the processing efficiency. Can be realized.

In the sequential forming method according to the present invention, since the rotation angle around the axis of the sequential forming tool is selected according to the part of the formed product to perform the forming, the processing surface contacted with the metal plate according to the rotation angle is selected. The radius of curvature is different, and the contact area with the metal plate is also different. As a result, the sequential forming method can perform forming according to the part of the molded product using a single sequential forming tool, and increase the pitch, which is the displacement width of the moving path, to perform processing. It is possible to improve efficiency.

It is sectional drawing explaining the outline of a successive forming method. It is a front view and a bottom view explaining a 1st embodiment of a tool for successive formation of the present invention. It is a plane explanatory view showing a locus of movement of a tool for successive forming. It is explanatory drawing which shows the difference of the contact area of a tool for successive forming. It is sectional drawing which shows the case where a rotation speed is larger than the feed speed of a tool for successive forming. It is sectional drawing which shows the case where a rotation speed is smaller than the feed speed of a tool for successive forming. It is a graph which shows the relationship between the surface roughness of a tool for successive forming, and the surface roughness of a to-be-processed surface. It is a front view and a bottom view explaining a 2nd embodiment of a tool for successive formation of the present invention. It is a front view and a bottom view explaining a 3rd embodiment of a tool for successive formation of the present invention.

<First Embodiment>
The sequential forming tool T shown in FIG. 1 is a rod-shaped tool used for sequentially forming a flat metal plate W into a three-dimensional shape. The successive forming tool T has a main body M having a constant diameter and a machining head H continuous with the tip of the main body M. In the successive forming tool T, the outer peripheral surface of the processing head H, that is, the outer peripheral surface in a predetermined range from the tip end to the axial direction is set as the processing surface A, and the processing surface A has a curvature radius in a cross section orthogonal to the axial direction. It is formed with partially different contour lines. The specific shape of this successive forming tool T will be described later.

In the sequential forming method using the above-described sequential forming tool T, as shown in the upper part of FIG. 1, the periphery of the flat metal plate W is held by the fixing device 1. The illustrated fixing device 1 includes a lower fixture 1A and an upper movable fixture 1B. The metal plate W is sandwiched between the fixture 1A and the movable fixture 1B. Hold firmly.

The successive forming tool T is held by a drive device (not shown) with its tip facing downward, is movable in three orthogonal axis directions, and is rotatable about its axis. A multi-axis control type robot, an NC machine tool, or the like can be used as the drive device. However, the successive forming tool T of the present invention is more preferably a multi-axis control type robot when the axis line is inclined, and the main body part M is attached to the hand part of the robot.

Next, in the sequential forming method, the sequential forming tool T is pressed against a predetermined portion of the metal plate W holding the periphery thereof with a constant pressure and moved along a predetermined movement path. In the illustrated example, since the metal plate W is formed into the rectangular concave formed product F, the moving path of the successive forming tool T is a circular path. Then, in the successive forming method, the amount of pushing (the amount of forward movement/the amount of descending) of the successive forming tool T into the metal plate W and the movement path are displaced stepwise for each revolution. At this time, the movement path is gradually displaced toward the center side of the metal plate W. The displacement width of this moving path is the pitch.

As a result, in the sequential forming method, as shown in the lower part of FIG. 1, the metal plate W is gradually deformed in the plate thickness direction to form the inclined side part S so as to push down the bottom part B, and the metal plate W is formed. Molded into a three-dimensional molded product F.

As described above, in the successive forming tool T, the machining surface A is formed by the contour lines having partially different radii of curvature in the cross section orthogonal to the axial direction. Further, as a more preferable embodiment, the successive forming tool T may have a shape in which a contour line forming the processing surface A includes at least one of a parabola, an elliptic curve and an arc in a part thereof.

In the successive forming tool T of this embodiment, as shown in FIG. 2, the cross-sectional shape of the processing head H, that is, the contour line of the processing surface A is elliptical. Further, in the successive forming tool T, it is assumed that the machined surface A has a shape having a vertical R portion Rt at the corner between the tip surface and the side surface, and the surface roughness of the machined surface A is Ra 0.2 μm or less. There is. The basis of this surface roughness will be described later.

The above-described successive forming method using the successive forming tool T is basically the same as the step shown in FIG. 1, and the successive forming tool T is pressed against the metal plate W holding the periphery to make a predetermined movement path. By moving, the pushing amount of the forming tool T into the metal plate W and the moving path are gradually displaced. At the start of forming shown in the upper part of FIG. 1, by successively inclining the axis of the forming tool T and bringing the portion of the minimum radius of curvature of the processing surface A or the vertical R portion Rt into contact with the metal plate W, unforming is performed. It is also effective to concentrate the load on the metal plate W.

Then, in the sequential forming method, the rotation angle around the axis of the sequential forming tool T is selected according to the part of the formed product to perform the forming. Since the molded product F of this embodiment has a rectangular concave shape as described above, as shown in FIG. 3, the side portion S has long and short straight line regions D and four corner regions. There is C. Therefore, in the sequential forming method, the rotation angle of the sequential forming tool T is selected according to the size of the radius of curvature of the molded product R, and the region of the molded product F having a small radius of curvature is the region of the processed surface A having a small radius of curvature. Mold with. Further, the portion of the molded product F having a large radius of curvature is formed at the portion of the processing surface A having a large radius of curvature.

Specifically, in the sequential molding method, the corner area C of the molded product F having a small radius of curvature is molded with the major axis side surface of the machined surface A having a small radius of curvature, and the curvature of the molded product F is reduced. The straight line region D having a large radius is formed by the surface on the minor axis side having a large radius of curvature of the processing surface A.

That is, in the sequential forming method, as shown in the movement trajectory of the sequential forming tool T in FIG. 3, a portion of the machining surface A having a large radius of curvature (a surface on the minor axis side) is brought into contact with the linear region D to be constant. It is moved at the feed speed Vf. Next, in the sequential forming method, as the corner region C is approached, the sequential forming tool T is rotated about the axis, and the corner region C is formed at a portion of the processing surface A having a small radius of curvature (a surface on the major axis side). Then, the successive forming method further rotates the successive forming tool T around the axis as the corner area C is separated, and the next straight line area D is formed at a portion of the machining surface A having a large radius of curvature (a surface on the minor axis side). Mold.

That is, in the successive forming tool T and the successive forming method using the same, as shown by a dotted arrow in FIG. 3, the successive forming tool T is circulated along the movement path and while passing through the corner region C. Then, by sequentially rotating (Vt) the tool T for molding in one direction around the axis, molding according to the part of the molded product F is performed.

Here, since the contour line of the machined surface A of the successive forming tool T is elliptical, as shown in FIG. 4, the contact area S1 of the surface on the short diameter side, which is a portion having a large radius of curvature (width is shown). ) Is larger than the contact area S2 of the surface on the minor axis side, which is a portion having a small radius of curvature. In the elliptical shape, this contact area continuously changes from the surface on the short diameter side to the surface on the long diameter side.

That is, the successive forming tool T has both a small-diameter tool having a diameter at least equivalent to the short diameter and a large-diameter tool having a diameter equivalent to the long diameter. Strictly speaking, from the small-diameter tool to the large-diameter tool. It has a machined surface A whose radius of curvature continuously changes in a region up to the tool. As a result, the successive forming tool T can increase the pitch, which is the displacement width of the movement path, particularly when forming by the portion of the processing surface A having a large radius of curvature (the surface on the short diameter side). is there. In other words, the successive forming tool T can perform excellent forming even at a large pitch.

Further, in the above-described successive forming method, as shown in FIGS. 4 and 5, when the successive forming tool T is rotated around the axis, the metal plate W is moved in the moving direction (arrow Vf) of the successive forming tool T. It is rotated in a direction (arrow Vt) in which the sliding direction with respect to is opposite. As a result, the frictional resistance with the metal plate W and the shearing resistance generated in the metal plate W are reduced, and flaking is prevented from occurring. Since the successive forming tool T is moving at a constant feed speed Vf, when it is rotated in a direction opposite to the illustrated example (reverse direction of Vt), frictional resistance between the metal plate W and the metal is increased. The shear resistance generated on the plate W increases, which is not preferable for preventing flaking.

Further, in the above-described successive forming method, as shown in FIG. 4 in a more preferable embodiment, the feed speed in the moving direction of the successive forming tool T is Vf, and the rotation speed around the axis of the successive forming tool is Vt. The rotation speed Vt is made higher than the feed speed Vf (Vt>Vf). As a result, the frictional resistance with the metal plate W and the shearing resistance generated on the metal plate W are further reduced, and the occurrence of flaking is more reliably prevented.

As shown in FIG. 5, even if the rotation speed Vt is lower than the feed speed Vf (Vt<Vf), flaking can be prevented. In this case, however, the successive forming tool T The rise E of the meat of the metal plate W is likely to occur in front of the movement. Although the bulge E of the meat is eliminated by the successive passage of the forming tool T, it causes an increase in frictional resistance generated between the meat and the metal plate W. On the other hand, as described above, if the rotation speed Vt is set higher than the feed speed Vf (Vt>Vf), the formation of the meat bulge E can be suppressed and the molding can proceed, resulting in friction resistance and shearing. The resistance also becomes smaller.

Further, in the successive forming tool T, as described above, the surface roughness of the processed surface A is Ra 0.2 μm or less. FIG. 7 is a graph showing the relationship between the surface roughness of the tool and the surface roughness of the surface to be processed (surface of the molded product F) under different processing conditions (tool moving speeds) A to C. As is clear from the figure, under any of the processing conditions A to C, when the surface roughness of the tool exceeds Ra 0.2 μm, the surface roughness of the surface to be processed becomes large, and especially the moving speed is relatively slow. Under the processing condition A, the surface roughness of the surface to be processed is significantly increased. On the other hand, under any of the processing conditions A to C, it can be seen that if the surface roughness of the tool is Ra 0.2 μm or less, the surface roughness of the processed surface can be kept small.

As described above, in the successive forming tool T, the machining surface A is formed by the contour lines having partially different radii of curvature in the cross section orthogonal to the axial direction, and the contour line of the machining surface A is one of the contour lines. The shape has a shape including at least one of a parabola, an elliptic curve, and an arc. As shown in FIG. 4, this successive forming tool T selects a rotation angle around the axis with respect to the metal plate W, so that the radius of curvature of the processing surface A that abuts the metal plate W according to the rotation angle. And the contact area with the metal plate W is also different.

As a result, the sequential forming tool T can perform forming according to the part of the formed product F, even if it is a single tool, and the pitch, which is the displacement width of the movement path, is increased to increase the processing time. Can be shortened and the processing efficiency can be improved. Further, since the successive forming tool T does not require tool replacement, this also realizes a reduction in processing time.

Further, in the sequential forming method, as shown in FIG. 3, since the rotation angle around the axis of the sequential forming tool T is selected according to the part of the formed product F to perform the forming, the metal is formed according to the rotation angle. The radius of curvature of the machined surface A that abuts the plate W is different, and the contact area with the metal plate W is also different. As a result, in the sequential forming method, it is possible to perform forming according to the part of the formed product F by using the single sequential forming tool T, and increase the pitch which is the displacement width of the moving path. As a result, the processing time can be shortened and the processing efficiency can be improved.

Further, in the successive forming tool T, the processing surface A has a shape having a vertical R portion Rt at the corner between the front end surface and the side surface, so that the metal plate W always comes into contact with the curved surface. The occurrence of flaking can be surely prevented.

Further, in the successive forming tool T, by setting the surface roughness of the processed surface A to be Ra 0.2 μm or less, as shown in FIG. 7, the aggressiveness to the metal plate W is reduced, and forming defects such as flaking are caused. It is possible to successively form a high-quality molded product F having no defect.

Further, in the successive forming method using the above-described successive forming tool T, when the successive forming tool T is rotated about the axis, the sliding direction with respect to the metal plate is opposite to the moving direction of the successive forming tool T. Rotate in the direction. Thereby, the sequential forming method reduces the frictional resistance with the metal plate W and the shearing resistance generated in the metal plate W, and prevents flaking.

Further, in the successive forming method, the metal plate W is formed by increasing the rotational speed around the axis of the successive forming tool T by Vt (Vt>Vf) rather than the feed speed in the moving direction of the successive forming tool T. The frictional resistance between them and the shearing resistance generated in the metal plate W are further reduced, and flaking is more reliably prevented. As a result, a high quality molded product F can be obtained.

8 and 9 are views for explaining the second and third embodiments of the successive forming tool according to the present invention. The successive forming tool T of these embodiments has a processing head H at the tip of the main body M. In each successive forming tool T, the contour line forming the machining surface A, which is the outer peripheral surface of the machining head H, is formed by a contour line having a partially different radius of curvature in a cross section orthogonal to the axial direction. Each successive forming tool T has a polygonal basic shape as a basic shape, and has a curved portion corresponding to each side and a lateral R portion corresponding to each corner.

That is, in the successive forming tool T shown in FIG. 8, the contour line forming the machining surface A has a triangular basic shape, and the curved portion Q corresponding to three sides and the lateral R portion corresponding to three corners. Ry and the shape. Further, the successive forming tool T has a shape in which the processing surface A has a vertical R portion Rt at the corner between the front end surface and the side surface, as in the first embodiment.

Further, in the successive forming tool T shown in FIG. 9, the contour line forming the machining surface A has a quadrangular basic shape, and the curved portions Q corresponding to the four sides and the lateral R portions corresponding to the four corners. Ry and the shape. Even in this sequential forming tool T, the processing surface A has a shape having a vertical R portion Rt at the corner between the tip surface and the side surface.

In each of the above-described successive forming tools T, by selecting the rotation angle around the axis with respect to the metal plate W, the radius of curvature of the processing surface A abutting on the metal plate W differs depending on the rotation angle, The contact area with the metal plate W is also different. As a result, the successive forming tool T can perform forming according to the part of the formed product F even though it is a single tool, and the pitch, which is the displacement width of the movement path, is increased to improve the processing efficiency. Improvement can be realized. In addition, the successive forming tool T can shorten the machining time because the pitch can be increased and the tool need not be replaced.

In the successive forming tool T of each of the above-described embodiments, the curved portions Q have the same radius of curvature and the lateral R portions Ry have the same radius of curvature, but the respective radiuses of curvature should be different from each other. Is also possible. When forming a rectangular concave shaped product F as shown in FIG. 3, linear regions D and corner regions C are alternately present on the circumference, and when the corner region C is passed through, successive molding is performed. Since the tool T is rotated, it is preferable that the curved portions Q and the lateral R portions Ry have the same radius of curvature.

Further, the sequential forming tool T of each embodiment is mounted on a driving device such as a multi-axis control type robot or an NC machine tool as described above. Therefore, in the driving device, if the data of the molded product F and the processed surface A are input in advance and the rotation angle of the molding tool T can be detected successively, each part of the molded product F is appropriately processed. The rotation of the forming tool T can be sequentially controlled so as to perform the forming at various portions.

The sequential forming tool and the sequential forming method according to the present invention are not limited to the above-described embodiments, and the details of the configuration can be appropriately changed without departing from the scope of the present invention. Furthermore, in each of the above-described embodiments, the case where the tool arranged on the upper side of the metal plate is used for the successive forming is illustrated, but it is also possible to make the metal plate stand up and press the tool from the lateral direction to perform the successive forming. However, it is also possible to move the metal plate holding the periphery.

A Processed surface C Corner area (a part with a small radius of curvature of the molded product)
D Straight line area (a part with a large radius of curvature of the molded product)
F Molded product Q Curved part Ry Horizontal R part Rt Vertical R part T Sequential forming tool Vf Feed rate Vt Rotational speed W Metal plate

Claims (8)

A rod-shaped tool, wherein an outer peripheral surface in a predetermined range from the tip end to the axial direction is used as a processing surface, and the processing surface is formed with contour lines having partially different radii of curvature in a cross section orthogonal to the axial direction. Using a sequential forming tool,
A metal plate holding a periphery, said moving the incremental forming tool to be pressed against a predetermined path of movement, by the displacing sequentially the push amount and the movement path of the molding tool stepwise, the metal plate three-dimensional When sequentially forming shaped articles,
Incremental forming method and performing molding by selecting the rotation angle around the axis of the incremental forming tool according to the site of the molded article. The rotation angle of the forming tool is sequentially selected according to the size of the radius of curvature of the molded product, and the region of the molded product having a small radius of curvature is molded at the region of the machined surface having a small radius of curvature. The sequential molding method described in 1. The sequential forming tool according to claim 2, wherein when the sequential forming tool is rotated about the axis, the sequential forming tool is rotated in a direction in which the sliding direction with respect to the metal plate is opposite to the moving direction of the sequential forming tool. Method. A feeding speed in the moving direction of the successive forming tool is Vf, a rotation speed around the axis of the successive forming tool is Vt, and the rotation speed Vt is higher than the feeding speed Vf (Vt>Vf). Item 4. The sequential molding method according to Item 3. The sequential forming method according to claim 1, wherein a contour line forming the machining surface of the sequential forming tool has a shape including a part of at least one of a parabola, an elliptic curve, and an arc. The contour line forming the machining surface of the successive forming tool is a shape having a polygon as a basic shape and having a curved portion corresponding to each side and a lateral R portion corresponding to each corner. The sequential molding method according to claim 1. The sequential forming method according to claim 1, wherein the processing surface of the sequential forming tool has a shape having a vertical R portion at a corner between a front end surface and a side surface. The successive forming method according to claim 1, wherein the surface roughness of the machined surface of the successive forming tool is Ra 0.2 μm or less.

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