JP2017170483A - Incremental molding method and molding tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of being limited to local molding since conventional incremental molding is unfit for molding a molding part of which an outside surface becomes an appearance.SOLUTION: In an incremental molding method, a first molding part 2A and a second molding part 2B of a tool 2 are selectively pressed for molding in response to a part of a metal plate W, by using the tool 2 having the first molding part 2A of the tip center composed of a plane or a curved surface and the second molding part 2B on the tip periphery relatively large in curvature to the first molding part 2A, when molding in the final shape by gradually deforming the metal plate W in the plate thickness direction, by pressing and moving the tool 2 to the metal plate W for holding the periphery. A molding part M having an excellent appearance quality is provided, even when molding the molding part M of which an outside surface becomes an appearance.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an incremental forming method for forming a three-dimensional shape by gradually deforming a metal plate by pressing and moving the tool against the metal plate, and a forming tool used therefor.

  Conventionally, as incremental molding, there is one described in Patent Document 1 under the name of dieless forming of a plate material. In the incremental molding described in Patent Document 1, a plate material holding mechanism for fixing the periphery of a thin metal plate, a tool arranged on the upper side of the thin metal plate held by the plate material holding mechanism, and a fixed pressing mechanism arranged on the lower side of the thin metal plate, Is used. The tool has a hemispherical shape with a constant curvature at the tip.

  Then, the above-described incremental molding is performed by restraining the periphery of the metal thin plate with a plate material holding mechanism, pressing the metal thin plate against the fixed pressing mechanism, and pressing and moving the tool on the upper surface of the metal thin plate, The thin plate is gradually deformed along the fixed pressing mechanism. At this time, the forming device circulates the tool pressed against the metal thin plate, and lowers the plate material holding mechanism in accordance with this while lowering the tool while laterally moving the tool outward.

  Thereby, the said incremental shaping | molding changes a metal thin plate gradually by making a fixed press mechanism inside, and shape | molds the said metal thin plate in a three-dimensional final shape. The final shape is a concave shape opened to the lower side.

Japanese Patent No. 4287912

  However, in the conventional incremental molding as described above, since the metal thin plate is pressed against the fixed pressing mechanism and the tool is pressed against the outer surface on the opposite side of the fixed pressing mechanism, the outer surface has an external appearance. It was unsuitable for molding of a molded product. That is, in the above-described incremental molding, the outer surface that becomes the appearance is the contact surface of the tool, and there is a possibility that a striped impression by the tool may be generated on the outer surface.

  Therefore, when molding a molded product having an outer surface as an appearance, it is conceivable to use a concave fixed pressing mechanism and gradually deform the thin metal plate along the inner side of the fixed pressing mechanism. That is, the inner surface of the molded product is used as the contact surface of the tool. However, in the conventional incremental molding, the metal thin plate is compressed between the fixed pressing mechanism and the tool, so that the impression of the tool is transferred to the outer surface or the surplus material is produced at the end of the molding, resulting in an appearance quality. There is a risk of damage.

  For this reason, incremental molding using a fixed pressing mechanism is not a whole process when molding a molded product whose outer surface is an appearance, but is a linear part molding that is performed as an additional process for pre-molded molded products. In addition, it is limited to local molding such as molding of a portion that does not affect the appearance quality.

  The present invention has been made in view of the above-described conventional situation, and is an incremental molding method and molding capable of molding a molded product having good appearance quality even when molding a molded product having an outer side appearance. The purpose is to provide tools. The outer surface of the molded product is, for example, the outer peripheral surface when the molded product is concave, and the outer peripheral surface of the curve when the molded product is curved.

  The incremental forming method according to the present invention is a method in which a metal plate is gradually deformed in the plate thickness direction and formed into a final shape by pressing and moving a tool against the metal plate holding the periphery. In this incremental molding method, a tool including a first molded part at the center of the tip made of a flat surface or a curved surface and a second molded part around the tip having a relatively large curvature with respect to the first molded part is used. And the incremental shaping | molding method is characterized by performing shaping | molding by selectively pressing the 1st shaping | molding part and 2nd shaping | molding part of a tool according to the site | part of a metal plate.

  The forming tool according to the present invention is a tool used for incremental forming in which a metal plate is gradually deformed in a plate thickness direction and formed into a final shape by pressing and moving the tool against a metal plate holding the periphery. The molding tool includes a first molding part at the center of the tip made of a flat surface or a curved surface, and a second molding part around the tip having a relatively large curvature with respect to the first molding part. .

  Since the incremental forming method according to the present invention employs the above-described configuration, it can be formed with a tool having a curvature close to the final shape, and the forming is performed only by restraining the periphery of the metal plate. Striped indentation and material surplus due to are suppressed. As a result, according to the above-described incremental molding method, even when molding a molded product whose outer surface becomes an appearance, the molded product having a good appearance quality can be molded with the inner surface as a contact surface of the tool. it can.

  The forming tool according to the present invention can be formed with a curvature close to the final shape by adopting the above-described configuration, suppresses striped indentations and material surpluses on the metal plate, and the outer surface has an appearance. Even when a molded product is molded, a molded product having good appearance quality can be molded.

It is sectional drawing explaining the basic composition in 1st Embodiment of the incremental shaping | molding method concerning this invention. It is the side view and top view (A) explaining the tool whose 1st forming part is a plane, and the side view and top view (B) explaining the tool whose 1st forming part is a curved surface. It is sectional drawing explaining shaping | molding by a 1st shaping | molding part. It is sectional drawing explaining shaping | molding by a 2nd shaping | molding part. FIG. 5 is a cross-sectional view for explaining molding by a second molding unit following FIG. 4. It is sectional drawing which shows the state which looked at the metal plate shown in FIG. 5 from the feed direction of a tool. It is sectional drawing which shows the state which changed the feed direction of the tool inclined with respect to FIG. It is a top view of the outer panel of the engine hood explaining 2nd Embodiment of the incremental shaping | molding method concerning this invention. It is sectional drawing based on the AA in FIG. 8, Comprising: It is sectional drawing explaining shaping | molding of an outer panel. It is sectional drawing based on the AA line in FIG. 8, Comprising: It is sectional drawing explaining shaping | molding of the character line of an outer panel.

<First Embodiment>
As shown in FIG. 1, the incremental forming is performed by constraining the periphery of a flat metal plate W by a fixing device 1, pressing the forming tool 2 disposed on the upper side against the metal plate W, and moving the metal plate W. The metal plate W is formed into a three-dimensional molded product (final shape) M by being gradually deformed in the plate thickness direction. In the following description, “forming tool 2” is simply referred to as “tool 2”.

  The shape of the molded product (see FIG. 5) M is not particularly limited, but in this embodiment, the molded product M is a flat concave shape having a peripheral wall portion S and a bottom wall portion B. And has a linear ridge T projecting downward. The molded product M has an outer surface including the outer peripheral surface of the peripheral wall portion S as an appearance.

  In addition, although the overall illustration of the molding apparatus is omitted, for example, a multi-axis control type working robot, an NC machine tool, or the like can be used. In addition, in the incremental forming method of this embodiment, it is desirable that the forming device has a high degree of freedom of movement of the tool 2 for the purpose of tilting the tool 2, and from this point of view, it is more preferable to use a work robot. It is.

  The fixing device 1 has a frame shape, and includes a lower fixing tool 1A and an upper movable tool 1B. The fixing device 1 clamps the periphery of the metal plate W to fix the movable tool 1B. Firmly restrain the surroundings.

  As shown in FIG. 2, the tool 2 has a round bar shape, and has a relatively large curvature with respect to the first molded portion 2A at the center of the tip, which is a flat surface or a curved surface, and the first molded portion 2A (curvature). And a second molding portion 2B around the tip (having a relatively small radius). The first molded part 2A includes a spherical surface as a curved surface.

  In the tool 2 shown in FIG. 2A, the first molding portion 2A is formed of a circular plane, and has a chamfered (R-shaped) second molding portion 2B on the outer periphery thereof. In the tool 2 shown in FIG. 2B, the first molding part 2A is formed of a spherical surface (curved surface), and the second molding part 2B having a curvature larger than the curvature of the first molding part 2A is provided on the outer periphery thereof. doing. The illustrated first molded portion 2A is a gentle spherical surface whose curvature is relatively small.

  In the above-described tool 2, more preferably, the first molding part 2A and the second molding part 2B have a curvature corresponding to the final shape (molded product M) to be molded. That is, when the tool 2 forms the molded product M having the peripheral wall portion S, the bottom wall portion B, and the ridge portion T as described above, the first molded portion 2A and the first molding portion 2A are formed according to the shape of the molded product M. 2 The shape and curvature of the molded part 2B are set.

  More specifically, the tool 2 is configured according to the angle of the peripheral wall portion S with respect to the bottom wall portion B, the width, height (groove depth) of the ridge portion T, the shape of the top portion (groove bottom portion), and the like. The 1 molding part 2A is made into a plane or a curved surface, and the curvatures of the first molding part 2A and the second molding part 2B are set. In addition, as for the tool 2, as shown in FIGS. 2A and 2B, it is possible to prepare a plurality of types having different tip shapes or different diameters.

  In the forming apparatus, the tool 2 is held so as to be movable in three orthogonal axes, and is held so as to be rotatable so that the inclination angle can be changed. The fixing device 1 and the tool 2 need only be relatively movable. The fixing device 1 may be stationary, or both may be movable so as to satisfy the relative movement in the three axial directions. Also good.

  In the incremental forming method, the above-described tool 2 is used, and the first forming part 2A and the second forming part 2B of the tool 2 are selectively pressed according to the portion of the metal plate W to perform forming. Further, as a more preferred embodiment, the incremental forming method is performed by inclining the tool 2 and pressing the second forming portion 2B against the metal plate W. Furthermore, as a more preferred embodiment, the incremental forming method is performed by pressing the tool 2 against the metal plate W while changing the inclination angle of the tool 2.

  That is, in the incremental molding method, as shown in FIG. 3, the periphery of the flat metal plate W is restrained by the fixing device 1, the tool 2 is pressed against one surface (upper surface) of the metal plate W, and the peripheral wall portion S Form.

  More specifically, in the incremental forming method, the tool 2 is placed in a vertical state with respect to the metal plate W, and the first forming portion 2A of the tool 2 is formed on the metal plate W where the peripheral wall portion S is to be formed. While rotating, the tool 2 is lowered while being moved toward the center of the metal plate W for each turn as shown by a thick arrow in FIG. At this time, the pressing force of the tool 2 against the metal plate W, the rotating speed of the tool 2, the moving amount and the descending amount of the tool 2 for each turn, the material and thickness of the metal plate W, the form of the peripheral wall portion S, and the form thereof Determine according to the site. In this way, the metal plate W is sequentially formed in a state where the peripheral wall portion S is inclined so that the bottom wall portion B is gradually lowered so as to shift from the flat state shown in FIG. 1 to FIG. 3.

  Next, as shown in FIG. 4, the incremental forming method inclines the tool 2 and presses the second forming portion 2 </ b> B of the tool 2 against the bottom wall portion B of the metal plate W, and the inclination direction (falling direction). The tool 2 is moved linearly. At this time, the tool 2 may be moved in one direction or may be reciprocated. Then, the incremental forming method repeats the linear movement of the tool 2 to gradually deform a part of the bottom wall portion B into a groove shape as shown in FIGS. 5 and 6, and to the outside (lower side). The protruding ridges T projecting to are sequentially formed.

  At this time, in the incremental forming method, the tool 2 can be pressed against the metal plate W while changing the inclination angle of the tool 2 in accordance with the portion of the metal plate W, and the protrusion (grooved portion) can be formed. Sequential forming can be performed by gradually increasing or decreasing the inclination angle of the tool 2 so that T reaches a desired final shape.

  Here, in the incremental forming method, when the protruding portion T is formed as described above, the protruding portion forming jig 3 can be disposed below the bottom wall portion B of the metal plate W. This jig 3 has a groove portion that is a reverse shape of the ridge portion T, and is locally arranged. At this time, in the incremental molding, it is not necessary to press the jig 3 against the metal plate W simply by arranging the jig 3, and the metal plate W is locally deformed along the jig 3 by pressing the tool 2. Let

  In the above-described incremental molding method, the tool 2 having the first molding part 2A and the second molding part 2B is used, and the first molding part 2A and the second molding part 2B are selectively pressed according to the part of the metal plate W. Thus, the tool 2 having a curvature close to the final shape can be formed. In addition, since the above-described incremental forming method basically only restrains the periphery of the metal plate W by the fixing device 1, the conventional fixed pressing mechanism is not required, and the metal plate W is significantly compressed. Therefore, the generation of striped indentation by the tool 2 is suppressed. Furthermore, the above-described incremental molding method uses the tool 2 to suppress a material surplus that is likely to occur in a tool having a hemispherical tip, and to prevent a protrusion due to the material surplus.

  In this way, according to the above-described incremental molding method, even when the molded product M whose outer side surface is appearance is formed, the inner side surface is used as the contact surface of the tool 2 and the molded product M having good appearance quality. Can be molded. Further, in the above-described incremental molding method, it is possible to cope with molding of each part of the molded product M with only one tool 2 having the first molding part 2A and the second molding part 2B.

  Further, in the above-described incremental forming method, the tool 2 is inclined and the second forming portion 2B is pressed against the metal plate W to form, so that a portion having a small curvature radius can be formed, for example, a broken line The corners and protrusions can be formed with high quality.

  Further, in the above-described incremental forming method, the main part and the local part can be formed without changing the tool by pressing the tool 2 against the metal plate W while changing the inclination angle of the tool 2. This can contribute to shortening the manufacturing cycle time, improving the productivity of the molded product M, and reducing the manufacturing cost.

  Further, in the above-described incremental forming method, the tool 2 has the first forming part 2A having a flat surface or a relatively gentle curved surface, so that the contact between the metal plate W and the first forming part 2A is surface contact. Or contact close to surface contact. For this reason, in the above-described incremental forming method, even if the lateral movement performed every rotation of the tool 2, that is, the pitch of the lateral movement with respect to the feed direction is increased, the metal plate W is successively formed without causing striped impressions. Molding becomes possible, and the molding time can be shortened by increasing the pitch of the lateral movement.

  Furthermore, since the molding tool 2 has the first molding part 2A and the second molding part 2B, molding with a curvature close to the final shape is possible, and a striped impression on the metal plate W or Even in the case of molding a molded product M in which the remainder of the material is suppressed and the outer surface becomes an appearance, the molded product M having a good appearance quality can be molded.

  Furthermore, since the above-mentioned forming tool 2 has a curvature corresponding to the final shape to be formed, the first forming part 2A and the second forming part 2B can be formed as designed with only one tool 2. The product M can be molded with high quality.

Second Embodiment
The incremental molding method shown in FIG. 7 is for molding a molded product M having a peripheral wall portion S, a bottom wall portion B, and a ridge portion T, as in the first embodiment. In the previous embodiment, as shown in FIGS. 5 and 6, after forming the peripheral wall portion S, the tool 2 is inclined when the ridge portion T is formed, and the tool 2 is inclined in the inclined direction (falling direction). Is moving.

  On the other hand, in this embodiment, when forming the ridge T, the tool 2 is inclined, and the tool 2 is linearly moved in a direction intersecting the inclination direction (perpendicular to the paper surface in FIG. 7). I am letting. Then, by repeatedly performing linear movement of the tool 2, a part of the bottom wall portion B is gradually deformed into a groove shape, and the protrusion T projecting outward (downward) is sequentially formed. At the time of forming the protruding portion T, it is possible to use a jig 3 indicated by a virtual line in the drawing.

  In the above-described incremental molding method, as in the previous embodiment, even when molding a molded product M having an outer side appearance, the molded product having a good appearance quality by using the inner side surface as a contact surface of the tool 2. M can be molded. Moreover, in the above-described incremental forming method, the protruding portion T having a smaller apex angle can be formed with high quality by making the moving direction of the inclined tool 2 the direction intersecting the inclined direction.

<Third Embodiment>
In the embodiment shown in FIGS. 8 to 10, the molded product (M) is an outer panel P of an automobile engine hood. The outer panel P has a gently curved main body portion corresponding to the bottom wall portion B, and has peripheral wall portions S that are continuous at a predetermined angle on both sides of the bottom wall portion B. In the outer panel P, the boundary line between the bottom wall portion B and the peripheral wall portion S is a character line CL having a locally small radius of curvature. The outer panel P is an outer surface whose outer peripheral side (the lower side in FIGS. 9 and 10) of the bottom wall B is curved.

  In the incremental forming method, when forming the outer panel P, the periphery of a flat metal plate (blank material) is constrained, the tool 2 is in a vertical state, and the first forming portion 2A is pressed against the metal plate W. A peripheral wall portion S is formed. At this time, in the incremental molding, the tool 2 is moved as in the previous embodiment, and the tool 2 is moved toward the center each time the tool 2 is moved, as indicated by a thick arrow in FIG. The peripheral wall portion S is sequentially formed so that the bottom wall portion B is pushed down while being laterally moved and the bottom wall portion B is pushed down.

  Next, in the incremental forming method, the first forming portion 2A of the tool 2 is pressed against the bottom wall portion B so as to be wetted with a dotted line in FIG. 9, and the tool 2 is moved laterally toward the center for each turn. Then, the bottom wall portion B is successively formed into a gently curved shape.

  Thereafter, in the incremental forming method, the boundary line between both is formed by forming the peripheral wall portion S and the bottom wall portion B. However, as shown in FIG. 10, the tool 2 is inclined and the second forming portion 2B is bounded. Press inside the line to move it. Thereby, in the incremental forming method, the boundary line portion is gradually deformed so that the radius of curvature becomes smaller, and the polygonal character line CL is sequentially formed.

  In addition, the circumference | surroundings of the outer panel P restrained by the fixing device which is not illustrated remain as the flange F, and other shaping | molding and cutting are performed as needed.

  Thus, in the above-described incremental molding method, when the outer panel P is molded, the tool 2 is selectively used by using the first and second molding parts 2A and 3B of the tool 2 arranged on the back side thereof. Therefore, it is possible to provide an outer panel having a good appearance quality free from striped indentation or material surplus due to the above. In addition, the above-described incremental molding method can improve the quality of the peripheral wall portion S having a predetermined inclination angle, the gently curved bottom wall portion (main portion), and the local character line CL with only one tool 2. Can be molded.

  The incremental molding method according to the present invention is not limited to the above-described embodiments, and the details of the configuration can be appropriately changed without departing from the gist of the present invention. Furthermore, in each said embodiment, although the case where sequential shaping | molding was performed with the tool arrange | positioned on the upper side of the metal plate W was illustrated, it is also possible to make the metal plate W upright and press the tool 2 from the lateral direction to form sequentially. Is possible.

2 Tool 2A 1st forming part 2B 2nd forming part M Molded product (final shape)
P Outer panel (molded product)
W Metal plate

Claims (5)

When pressing the tool against the metal plate holding the periphery and moving it, the metal plate is gradually deformed in the plate thickness direction to form the final shape,
Using a tool provided with a first molding part at the center of the tip made of a flat surface or a curved surface, and a second molding part around the tip having a relatively large curvature with respect to the first molding part,
An incremental forming method, wherein forming is performed by selectively pressing a first forming portion and a second forming portion of a tool according to a portion of a metal plate.   The incremental forming method according to claim 1, wherein the forming is performed by inclining the tool and pressing the second forming portion against the metal plate.   3. The incremental forming method according to claim 1, wherein the forming is performed by pressing the tool against the metal plate while changing the tilt angle of the tool. A tool used for incremental molding, in which a metal plate is gradually deformed in the thickness direction and formed into a final shape by pressing and moving the tool against the metal plate holding the periphery,
A molding tool comprising: a first molded part at the center of the tip made of a flat surface or a curved surface; and a second molded part around the tip having a relatively large curvature with respect to the first molded part.   The molding tool according to claim 4, wherein the first molding part and the second molding part have a curvature corresponding to a final shape to be molded.

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