JP6847398B2 - Sequential molding method - Google Patents

Description

The present invention relates to a sequential molding method in which a metal plate is gradually deformed and formed into a three-dimensional shape by pressing a tool against the metal plate and moving the metal plate. In particular, a flange is formed on a metal plate having a flat surface portion and a curved surface portion. It relates to a sequential molding method used in the above.

As a conventional sequential molding method, for example, there is one described in Patent Document 1. The sequential forming method described in Patent Document 1 uses a support frame for fixing the periphery of the plate material (metal plate), a mold pressing member arranged on the lower surface side of the plate material, and a rod-shaped tool arranged on the upper surface side of the plate material. To do. The mold pressing member is, in short, a molding mold having a surface shape corresponding to the final shape of the plate material.

In the above-mentioned sequential molding method, the mold pressing member is pressed against the lower surface of the plate material whose circumference is fixed, and the tip of the tool is pressed against the upper surface of the plate material to move a predetermined path, thereby moving the plate material in the thickness direction. Gradually transform. Then, in the sequential forming method, each time the tool is moved along a predetermined path, the advancing amount (descending amount) of the tool is increased, so that the plate material is finally formed into a shape along the surface of the mold pressing member. To do.

Japanese Unexamined Patent Publication No. 2003-236618

By the way, in the above-mentioned sequential molding method, in particular, when forming a flange from a flat surface portion to a curved surface portion on a metal plate having a flat surface portion and a curved surface portion, a molding die having a surface shape corresponding to the flange is used. become. However, in such a conventional sequential molding method, there is a problem that the production cost of the molding occupies a large part of the manufacturing cost, and it is a problem to solve such a problem.

The present invention has been made by paying attention to the above-mentioned conventional problems, and in particular, a sequential forming method used for forming a flange from a flat surface portion to a curved surface portion on a metal plate having a flat surface portion and a curved surface portion. It is an object of the present invention to provide a sequential molding method capable of forming a flange satisfactorily without using a molding die while realizing a reduction in manufacturing cost by abolishing a molding die.

The sequential molding method according to the present invention is to press the tip of a tool against a metal plate holding a periphery to move a predetermined path, thereby gradually deforming the metal plate in the thickness direction to form a three-dimensional shape. In particular, the metal plate has a flat surface portion and a curved surface portion continuous thereto, and a flange extending from the flat surface portion to the curved surface portion is formed on the metal plate. Then, in the sequential forming method, one tool and the other tool arranged with the metal plate in between are used, and in the flat portion of the metal plate, the axes of both tools are shifted from each other and a flange is formed between the two tools. The curved portion of the metal plate is characterized in that the flange is formed by making the distance between the axes of both tools relatively larger than the distance between the axes of both tools on the flat surface portion.

According to the sequential molding method according to the present invention, by adopting the above configuration, a flange from the flat surface portion to the curved surface portion is formed on the metal plate having the flat surface portion and the curved surface portion by using a pair of tools. Therefore, in particular, by increasing the distance between the axes of both tools on the curved surface portion, it is possible to prevent molding defects such as wrinkles that are likely to occur on the curved surface portion.

In this way, in the sequential molding method, when forming a flange on a metal plate having a flat surface portion and a curved surface portion, the molding die is abolished to realize a reduction in manufacturing cost, and the flange is formed without using a molding die. It can be formed well.

In the first embodiment of the sequential molding method according to the present invention, FIGS. (A) and (B) are a plan view (A) and a cross-sectional view (B) showing flange molding of an automobile engine hood which is an example of a molded product. Similarly, it is a perspective view which shows the flange molding of the engine hood for an automobile. It is a cross-sectional explanatory view (A) which shows the arrangement of a metal plate and a tool, and is a cross-sectional explanatory view (B) which shows the flange molding. It is sectional drawing which shows the detail of flange molding. It is sectional drawing which shows the 2nd Embodiment of the sequential molding method which concerns on this invention.

<First Embodiment>
1 to 4 are views for explaining a first embodiment of the sequential molding method according to the present invention. In the sequential molding method, the tip of a tool is pressed against a metal plate that holds the periphery to move a predetermined path, so that the metal plate is gradually deformed in the thickness direction and molded into a three-dimensional shape. In the sequential molding method according to the present invention, in particular, the metal plate has a flat surface portion and a curved surface portion continuous thereto, and a flange extending from the flat surface portion to the curved surface portion is formed on the metal plate.

1 and 2 are views showing flange molding of an automobile engine hood, which is an example of a molded product. The metal plate A is a precursor of the outer panel of the engine hood, and is formed in a three-dimensional shape. The metal plate A continuously has a flat surface portion B corresponding to the main body portion of the outer panel and a curved surface portion C corresponding to the front portion of the outer panel. Further, the metal plate A has a frame-shaped portion D over the entire circumference, and also has a slope portion E extending from the edge portion of the flat surface portion B and the curved surface portion C to the frame-shaped portion D. The metal plate A is not particularly limited, but is formed into the above three-dimensional shape by, for example, a pre-process such as sequential molding or press working.

In this embodiment, the flange F is continuously formed on the edges of the flat surface portion B and the curved surface portion C of the metal plate A. At this time, in the sequential molding method, the edges of the flat surface portion B and the curved surface portion C are formed in a stepped shape, but after this formation, the frame-shaped portion D and the slope portion E are cut off leaving the stepped portion. As a result, the stepped portion becomes the flange F of the outer panel. Therefore, in the sequential molding method, the stepped portion is referred to as the flange F.

In the above-mentioned sequential forming method, as shown in FIGS. 1B and 3, a jig 1 for holding the periphery of the metal plate A, one tool 2 and the other tool arranged with the metal plate A in between. 3 is used. The jig 1 has a frame shape corresponding to the periphery of the metal plate A, and is provided with a lower fixture 1A and an upper movable tool 1B, and is movable by sandwiching the frame-shaped portion D of the metal plate A. By fixing the tool 1B, the periphery of the metal plate A is firmly restrained.

One and the other tools 2 and 3 are round bar-shaped tools having a spherical tip, and are arranged on the upper surface side and the lower surface side of the metal plate A with their respective tips facing the metal plate A. It is done. Both tools 2 and 3 are held so as to be movable in the horizontal biaxial directions (X and Y directions) and the vertical directions (Z directions) that are orthogonal to each other. Further, both tools 2 and 3 may be held rotatably in order to incline the metal plate A in addition to the orthogonal three-axis directions. Examples of the holding device for these tools 2 and 3 include a multi-axis control type work robot.

Then, in the sequential forming method, on the flat surface portion B of the metal plate A, as shown in the cross-sectional view taken along the arrow 4A in FIG. 4, the axes 2A and 3A of both tools 2 and 3 are displaced from each other and both tools 2 are formed. A flange F is formed between, and 3. At this time, the distance L1 between the axes of both tools 2 and 3 is a distance that does not interfere with each other when moving forward. For example, when the diameters of both tools 2 and 3 are the same, the distance is larger than the diameter. is there.

Further, in the sequential forming method, in the curved surface portion C of the metal plate A, as shown in the cross-sectional view taken along the line 4B in FIG. 4, both tools are used with respect to the distance L1 between the axes of both tools 2 and 3 in the flat surface portion B. The flange F is formed by relatively increasing the distance L2 between the axes of a few. The cross-sectional views 4A and 4B in FIG. 4 are cross-sectional views based on the line-of-arrow view of PP in the same figure.

More specifically, both tools 2 and 3 are in a state where their axes 2A and 3A are parallel to each other and perpendicular to the flat surface portion B in the flat surface portion B, and the upper tools are arranged. 2 corresponds to the outside of the flange F, and the lower tool 3 corresponds to the inside of the flange F. Further, in the curved surface portion C, the distance between the axes is increased (L1 → L2) while keeping the directions of the axes 2A and 3B of both tools 2 and 3 in the same direction as the flat surface portion B. As a result, the flange F is formed downward from the edges of the flat surface portion B and the curved surface portion C.

In the sequential forming method, the positional relationship between the tools 2 and 3 is set as described above, and the tips of the tools 2 and 3 are pressed against the metal plate A to move the predetermined path. Since the predetermined route of this embodiment is the edge portion of the flat surface portion B and the curved surface portion C, the route from the end of the flat surface portion B to the end of the curved surface portion C via the boundary between the flat surface portion B and the curved surface portion C. Is. In this sequential forming method, the flat surface portion B moves both tools 2 and 3 in the horizontal direction, and the curved surface portion C increases the distance between the axes of both tools 2 and 3 (L1 → L2) and both tools 2 , 3 is moved horizontally while being lowered.

Then, in the sequential forming method, after moving the tools 2 and 3 along the predetermined path, the amount of advance of each tool 2 and 3 with respect to the metal plate A is increased, and the amount of advance is increased for each movement of the predetermined path. Repeat the operation to make it. As a result, the sequential forming method gradually deforms the metal plate A to finally form a flange F having a predetermined step size. In this embodiment, since the predetermined path is linear, both tools 2 and 3 may be moved in one direction, or may be reciprocated to shorten the molding time.

In the above-mentioned sequential molding method, one and the other tools 2 and 3 arranged on the upper and lower sides (both sides) of the metal plate A are used. Therefore, both tools 2 and 3 play a role of suppressing the metal plate A and the metal plate A. They will play the role of molding each other. Therefore, in the sequential molding method, the metal plate A does not move (escape) locally without using a conventional molding die, and the flange F is satisfactorily formed. Further, in the sequential forming method, since both tools 2 and 3 are locally brought into contact with each other for forming, in other words, the periphery of the forming portion is in an unconstrained state, so that it is easy to create a target shape.

In this way, in the above-mentioned sequential molding method, the flange F from the flat surface portion B to the curved surface portion C is formed on the metal plate A having the flat surface portion B and the curved surface portion C by using a pair of tools 2 and 3. It will be formed continuously. Further, in the sequential forming method, in the curved surface portion C of the metal plate A, the distance between the axes of both tools 2 and 3 L2 is relatively large with respect to the distance L1 between the axes of both tools 2 and 3 in the flat surface portion B. By forming the flange F, molding defects such as wrinkles and cracks that are likely to occur on the curved surface portion C are prevented.

As a result, in the sequential molding method, when forming the flange F on the metal plate A having the flat surface portion B and the curved surface portion C, the molding die, which occupies most of the manufacturing cost, is abolished and the manufacturing cost is reduced. Moreover, it is possible to satisfactorily form a high-quality flange F without using a molding die.

Further, as a more preferable embodiment, the sequential forming method is to change the distance L2 between the axes of both tools 2 and 3 according to the magnitude of the curvature of the curved surface portion C in the metal plate A, and when the curvature is large. Can increase the distance L2 between the axes. As a result, the sequential molding method can more reliably prevent molding defects such as wrinkles and cracks that are likely to occur on the curved surface portion C, even when the curvature of the curved surface portion C is large.

Further, as a more preferable embodiment of the sequential forming method, in the curved surface portion C of the metal plate A, both tools 2 and 3 are in a state where the axes 2A and 3A of both tools 2 and 3 are flush with respect to the curved surface portion C. Can be tilted to form the flange F. As a result, in the sequential forming method, the contact angles of both tools 2 and 3 with respect to the metal plate A become uniform, and the flange F can be more easily formed from the flat surface portion B to the curved surface portion C. The sequential forming method of inclining both tools 2 and 3 will be described in detail in the second embodiment described later.

Further, as a more preferable embodiment, in the sequential forming method, in the curved surface portion C of the metal plate A, the distance L2 between the axes of both tools 2 and 3 is gradually reduced (L2 → L1) for each movement of a predetermined path to form the flange F. Can be formed. As a result, in the sequential forming method, the angle of the flange F on the curved surface portion C gradually changes in the vertical direction, and it becomes possible to form the flange F having the same shape as the flat surface portion B. That is, according to the above-mentioned sequential forming method, the flange F having the same cross section can be formed in the entire range from the flat surface portion B to the curved surface portion C.

Further, as a more preferable embodiment of the sequential forming method, in the curved surface portion C of the metal plate A, the pressing amount of both tools 2 and 3 is relatively relative to the pressing amount of both tools 2 and 3 against the flat surface portion B. The flange F can be made smaller. As a result, the sequential molding method can more reliably prevent molding defects such as wrinkles and cracks that are likely to occur on the curved surface portion C.

<Second Embodiment>
FIG. 5 is a diagram illustrating a second embodiment of the sequential molding method according to the present invention. In the second embodiment, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Similar to the first embodiment, the sequential molding method of this embodiment forms a flange F from the flat surface portion B to the curved surface portion C on a metal plate A having a flat surface portion B and a curved surface portion C continuous thereto. One tool 2 and the other tool 3 arranged with the metal plate A in between are used.

Then, in the sequential forming method, as shown in the cross-sectional view 5A of the line PP in FIG. 5, the axes 2A and 3A of both tools 2 and 3 are displaced from each other. Further, in the sequential forming method, the flanges F are formed between the tools 2 and 3 so that the axes 2A and 3A of the tools 2 and 3 are flush with respect to the metal plate A.

That is, in this embodiment, in the flat surface portion B, the axes 2A and 3A of both tools 2 and 3 are arranged to be perpendicular to the metal plate A, that is, perpendicular to the flat surface portion B. Further, in the curved surface portion C, the axes 2A and 3A of both tools 2 and 3 are arranged in a plane with respect to the metal plate A, that is, in a state of being inclined so as to match the normal line of the curved surface portion C. In the curved surface portion C, the axes 2A and 3A of both tools 2 and 3 do not necessarily have to coincide with the normal.

At this time, in the first embodiment, when the flange is formed on the curved surface portion C, the distance between the axes of both tools 2 and 3 is relatively large (L1 → L2) with respect to the flat surface portion B. In this embodiment, the distance L1 between the axes of both tools 2 and 3 is made constant at the flat surface portion B and the curved surface portion C.

In the above-mentioned sequential molding method, as in the first embodiment, the tips of both tools 2 and 3 are pressed against the metal plate A to move a predetermined path, that is, a path along the edge portion of the flat surface portion B and the curved surface portion C. At this time, in the case of this embodiment, it is more desirable to start the formation of the flange F from the curved surface portion C in order to prevent molding defects. Therefore, the movement paths of both tools 2 and 3 are paths from the end of the curved surface portion C to the end of the flat surface portion B through the boundary between the curved surface portion C and the flat surface portion B.

As a result, in this sequential forming method, both tools 2 and 3 are tilted in the curved surface portion C and horizontally moved while being raised while gradually reducing the tilt angle, and both tools are tilted in the flat surface portion B. A few axes 2A and 3A are made vertical and moved horizontally.

Then, in the sequential forming method, the amount of advance of each of the tools 2 and 3 with respect to the metal plate A is increased each time the predetermined path is moved, and this is repeated to form the flange F. The flange F formed in this way has a constant cross-sectional dimension (cross-sectional shape) over the entire area from the curved surface portion C to the flat surface portion B.

In this way, the above-mentioned sequential molding method, as in the first embodiment, is a molding mold that occupies most of the manufacturing cost when forming the flange F on the metal plate A having the flat surface portion B and the curved surface portion C. It is possible to realize a reduction in manufacturing cost by abolishing the above, and to form a high quality flange F satisfactorily without using a molding die.

Further, in the above-mentioned sequential forming method, the flanges F are formed between the tools 2 and 3 so that the axes 2A and 3A of the tools 2 and 3 are in a plane with respect to the metal plate A, so that the curved surface portion is formed. It is possible to more reliably prevent molding defects such as wrinkles and cracks that are likely to occur in C, and it is not necessary to change the distance between the axes of both tools 2 and 3, and the flange F can be formed with a constant distance between the axes. Therefore, the movement control of the tools 2 and 3 becomes easier accordingly.

The sequential molding method according to the present invention is not limited to each of the above embodiments, and the details of the configuration can be appropriately changed without departing from the gist of the present invention. In each of the above embodiments, the case where the metal plate A is sequentially formed by a pair of tools 2 and 3 arranged above and below the metal plate A is illustrated, but the metal plate A is kept upright and the tools 2 and 3 are pressed from the lateral direction. Sequential molding is also possible, and for example, the jig may be movable.

Further, the sequential molding method according to the present invention is applicable not only to the outer panel of an automobile engine hood but also to the formation of flanges on various metal plates having a flat surface portion and a curved surface portion. Since flanges are formed on the entire circumference of the outer panel, for example, it is possible to simultaneously form the left and right flanges with a pair of tools.

Further, in each of the above embodiments, the distance between the axes of the tools 2 and 3 and the pressing amount and the inclination angle are controlled, but it is naturally possible to control the speed of the tools 2 and 3. Further, both tools 2 and 3 do not necessarily have to have the same form, and it is also possible to use tools having different tip curvatures and diameters.

A Metal plate B Flat surface C Curved surface F Flange L1, L2 Distance between tool axes 2 One tool 2A, 3A Tool axis 3 The other tool

Claims (6)

In a sequential molding method in which a metal plate is gradually deformed in the thickness direction to form a three-dimensional shape by pressing the tip of a tool against a metal plate holding the periphery and moving a predetermined path.
The metal plate has a flat surface portion and a curved surface portion continuous thereto, and when forming a flange from the flat surface portion to the curved surface portion on the metal plate,
Using one tool and the other tool placed with a metal plate in between,
On the flat surface of the metal plate, the axes of both tools are offset from each other to form a flange between the tools.
A sequential molding method characterized in that a flange is formed on a curved surface portion of a metal plate by making the distance between the axes of both tools relatively large with respect to the distance between the axes of both tools on a flat surface portion. The sequential according to claim 1, wherein the distance between the axes of both tools is changed according to the magnitude of the curvature of the curved surface portion of the metal plate, and the distance between the axes is increased when the curvature is large. Molding method. The sequential molding method according to claim 1 or 2, wherein the curved surface portion of the metal plate is formed by inclining both tools so that the axes of both tools are perpendicular to the curved surface portion. The sequential molding method according to any one of claims 1 to 3, wherein a flange is formed on the curved surface portion of the metal plate by gradually reducing the distance between the axes of both tools each time the movement of a predetermined path is performed. Any one of claims 1 to 4, wherein in the curved surface portion of the metal plate, the pressing amount of both tools is relatively small with respect to the pressing amount of both tools against the flat surface portion to form a flange. The sequential molding method described in 1. In a sequential molding method in which a metal plate is gradually deformed in the thickness direction to form a three-dimensional shape by pressing the tip of a tool against a metal plate holding the periphery and moving a predetermined path.
The metal plate has a flat surface portion and a curved surface portion continuous thereto, and when forming a flange from the flat surface portion to the curved surface portion on the metal plate,
Using one tool and the other tool placed with a metal plate in between,
The axes of both tools are shifted parallel to each other, the axes of both tools are perpendicular to the metal plate, and the distance between the axes of both tools is kept constant to form a flange between the tools. Sequential molding method characterized by

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