KR101917450B1 - Roll Stamping Device and Method - Google Patents

Abstract

An object of the present invention is to provide a roll stamping apparatus capable of eliminating unevenness of force between a residual stress and a section changing portion of a cross section changing portion, A forming part to which a stamping structure is applied on the outer surface of the roller set to form the material and an escape part for passing the material at a position different from that of the forming part, Wherein each of the forming portions of the roller set is formed so as to sequentially change the cross-section of the material in accordance with the progress of the material, wherein at least one of the roller sets before the last roller set through which the material passes last, Has a length in the circumferential direction of the forming portion of the final roller set A roll stamping device is provided which is a longer overmolding roller set.

Description

[0001] Roll Stamping Device and Method [

The present invention relates to a roll stamping apparatus and a roll stamping method including a forming part to which a stamping structure is applied to an outer surface and a rotating roll having an escape part for passing the material.

In general, a large number of sheet material forming techniques for producing parts to be applied to automobiles and the like are being developed.

The stamping method is composed of a top die, a lower punch disposed below the upper die, and a material holder disposed between the upper die and the lower punch. Here, the upper die is a frame member formed on the bottom surface of the groove portion, which is shaped in accordance with the shape of the molded article to be molded, and the lower punch is disposed on the lower portion of the upper die and driven upward, thereby pushing up the material advancing between the upper die and the lower punch To the upper die.

Such a stamping method is widely used for producing a molded article as an automobile part. However, recently, there has been a problem of increasing the apparatus capacity in the application of high-strength steel and a problem that the material is broken at the time of molding due to the poor moldability of the high- have.

Next, there is a roll forming (RF) method. In the roll forming method, a plurality of fixed upper and lower rotary roll sets are arranged and a coil or cut material is passed between the upper and lower rotary roll sets. And a molded article having a long length is molded.

The roll forming method using such a roll forming apparatus can be applied to a high strength steel by utilizing a relatively small capacity apparatus, but it has a limitation in that it can not but manufacture molded articles having a constant sectional shape.

Thus, a roll stamping method as in Patent Document 1 has been developed. In the roll stamping method, a stamping structure is applied to a rotating rotary roll, so that the material is subjected to variable cross-sectional roll forming while passing through a rotary roll.

However, in the case of such a roll stamping method, there is a problem that defects such as residual stress in the section changing portion and warping due to unbalanced force between the respective sectional changing portions in the component occur.

(Patent Document 1) KR1417278 B

An object of the present invention is to provide a roll stamping apparatus and method capable of eliminating the imbalance in force between the residual stress and the cross-section changing portion of the cross-sectional changing portion, thereby preventing the shape defects and adjusting the forming portion forming interval.

The present invention provides a roll stamping method and apparatus for achieving the above objects.

The present invention provides, as one embodiment, a roller set which rotates while facing each other so as to press both sides of a continuous material to be fed, a forming part having a stamping structure applied to an outer surface of the roller set to form the material, A plurality of rollers are disposed along the material advancing direction and each of the forming units of the roller set is formed so as to sequentially change the cross section of the material in accordance with the progress of the material , The forming portion of at least one of the roller sets before the last set of rollers through which the material passes last is a set of forming rollers having a longer circumferential length than the forming portion of the last set of rollers, A roller set for forming a material in a direction opposite to a direction in which the material is deformed in the over-molding roller set .

In one embodiment, the overforming roller set may be disposed within at least three of the last set of rollers.

In one embodiment of the present invention, the forming unit may be configured to have an engraved opening on both sides of the outer surface of one rotary roll of the roller set, and an embossment corresponding to the engraving on the outer surface of the other rotary roll.

In one embodiment of the present invention, the shaping portion of the roller set is formed to sequentially planarize by removing the concave-convex portion of the material cross section, and the shaping portion of the final roller set and overforming roller set is flat in the width direction, Wherein the circumferential length of the flat portion of the over-forming roller set is longer than the circumferential length of the flat portion of the final roller set, wherein the circumferential length of the flat portion of the over-forming roller set is longer than the circumferential length of the flat portion of the final roller set. .

According to an embodiment of the present invention, the forming portion of the over-molding roller set includes a flat portion having a predetermined length in the circumferential direction and a transverse portion positioned on both sides of the flat portion in the circumferential direction, The circumferential length of the transition portion of the roller set may be greater than the circumferential length of the transition portion of the last set of rollers.

In one embodiment of the present invention, the escape portion may be formed on the opposite side of the forming portion, and the escape portion may be recessed radially inward from the outer peripheral surface of the roller.

Alternatively, a roll stamping method for roll stamping using a roll stamping apparatus, comprising: a primary forming step of forming a material into a molded part of the roller set; A bypass step of passing the material through an escape portion of the roller set to bypass the material; And a secondary forming step of re-forming the material into a molded part of the roller set.

In one embodiment of the present invention, the ratio of the feed rate of the material to the rotational speed of the roller set may be different from each other in the first molding step and the bypass step.

The unevenness of the force between the residual stress and the section changing portion of the section changing portion can be solved through the roll stamping apparatus and method of the present invention, so that there is no defective shape and the forming portion forming interval can be adjusted.

1 is a view showing a conventional roll stamping apparatus.
2 is a plan view of a product manufactured by a conventional roll stamping apparatus.
3 is a view showing a roll stamping apparatus of the present invention.
4 is a stepwise plan view of a product manufactured by the roll stamping apparatus of the present invention.
5 is a plan view showing the final shape of the product by the roll stamping apparatus of the present invention and the shape of the product molded in the over-molding roller set.
6 is a plan view showing the final shape of the product by the roll stamping apparatus of the present invention and other product shapes formed in the over-molding roller set.
7 is a photograph of a product molded by a conventional roll stamping apparatus and a product molded by the roll stamping apparatus of the present invention.
8 and 9 are views showing another embodiment of the roll stamping apparatus of the present invention.
Fig. 10 is a side view of the product molded by the roll stamping apparatus of Figs. 8 and 9. Fig.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Figures 1 and 2 show a conventional roll stamping apparatus and a product molded thereon. 1, a conventional roll stamping apparatus includes a plurality of roller sets 10, 20, 30, 40 arranged along the material advancing direction, and each roller set 10, 20, 30, 10a and a lower roll 10b. The rolls 10a, 10b are formed with forming portions 11a, 11b to form a material.

As shown in Fig. 1, each roller set 10, 20, 30, and 40 includes a shaping portion. The shaping portion is sequentially changed along the advancing direction of the material to form a part of the material in the first shape Is formed into a second shape different from the first shape.

The product formed by such a roll stamping apparatus has transition portions T1 and T2 formed by a portion having a first shape (cross-sections AA and CC) and a portion formed by a molding portion and having a second shape (cross-section BB) . These transitional portions T1 and T2 have residual stresses in opposite directions to each other, and there is a problem that they are cut into a product or twisted before cutting.

The present invention reduces the residual stress remaining in the transition portion or at least prevents warpage, thereby reducing the defective shape of the product. In Fig. 3, the roll stamping apparatus of the present invention for achieving this object is shown.

3, the roll stamping apparatus of the present invention includes roller sets 10, 20, 40, and 50 which are rotated while facing each other so as to press both sides of a continuously fed material S and press them, Wherein the roller set includes at least one roller set having a stamping structure applied to the outer surface of the roller set so as to form a roller set, ) Are arranged along the material advancing direction, and each forming portion of the roller set is formed so as to sequentially change the cross-section of the material in accordance with the progress of the material, The forming portions 51a and 51b of at least one roller set 50 of the roller set 50 are the forming roller set 40 having a longer circumferential length than the forming portions 41a and 41b of the final roller set 40 .

Fig. 4 is a stepwise plan view of the material to be formed by the roll stamping apparatus of Fig. 3, Fig. 4 (a) is a plan view of the material formed by the roller set 10 of Fig. 3, Fig. 4 (c) is a plan view of the material formed by the over-molding roller set 50 of Fig. 3, Fig. 4 (d) is a plan view of the material formed by the roller set 20 of Fig. And is a plan view of the material formed by the roller set 40. Fig.

As shown in Figs. 4 (a) to 4 (d), as the material S passes through the roller sets 10, 20, 40, and 50, the material whose cross section is hat- To a flat shape (second shape).

Here, the shape of the material or the number of the roller sets is an example, and the number of the roller sets may be increased or decreased as needed, and the shape of the material may have a shape corresponding to a desired product. In Figs. 4 (a) to 4 (d), the pre-forming material is shown to have the same width, but it is also possible to cut the material before the roll stamping.

Fig. 4 (a) is a plan view of the material passed through the first roller set 10, in which some regions 101, 102 and 103 of a material having a hat-shaped cross section are formed. Transitions 102 and 103 between the unformed region and the flat portion 101 are formed around the flat portion 101 having a flat outer surface in the plan view among the formed regions. The flat portion 101 of FIG. 4A means a region having the same cross section in the direction of travel of the material, regardless of whether the cross section is flat, and the transition portions 102 and 103 are regions in which the cross- .

4 (b) is a plan view of the material passed through the second set of rollers 20, in which some regions 101, 102, 103 of the material having a hat-shaped cross-section are formed more than the first roller set 10 1). However, the second roller set 20 and the first roller set 10 perform molding for the same length (L1 = L2).

Fig. 4 (c) is a plan view of the material passed through the over-molding roller set 50. Fig. Not only the partial regions 101, 102 and 103 of the material were formed more than the second roller set but also the length of the forming region became longer than the second one (L1 = L2 < L3). The length of the forming portions 51a and 51b of the over-forming roller set 50 is set to be longer than the length of the forming portions 51a and 51b in the circumferential direction Are formed longer than the circumferential lengths of the forming portions 11a, 11b of the first and second roller sets 10, 20.

4 (d) is a plan view of the material having passed through the overmoulding roller set 50 and then passing through the final set of rollers 40 and having the desired second shape. As shown in Fig. 4 (d), in the final roller set 40, the overmolded material is again inversely molded and formed into the target shape, so that the length L4 of the material forming area is smaller than the length L4 of the material forming area (L3 < L4). Accordingly, the transitions 102 and 103 where the material section changes from the first shape to the second shape in Fig. 4 (d) and the return sections 105 and 106, which are transitions in the previous roller set and returned to the first shape, (Hatched portion in Fig. 4 (d)) is formed in the direction opposite to the direction of the deformation from the first shape to the second shape.

Accordingly, the material transition portions 102 and 103 and the return portions 105 and 106 are formed in the reverse direction with respect to the residual stress direction formed by molding from the first shape to the second shape, and the residual stress of the final product is reduced can do.

4 (a) - (d) illustrate and illustrate that the overforming roller set 50 is disposed just before the last set of rollers 40, but not limited thereto, The set may consist of an overforming roller set 50.

In addition, the overforming roller set 50 includes not only a case in which the length of the material, that is, the circumferential length of the roll is longer than the circumferential length of the forming portion of the final roller set, (The first shape is not changed to the second shape but the third shape is changed to the third shape that is beyond the second shape and then the second shape is changed to the second shape) ). &Lt; / RTI &gt;

The roll stamping apparatus of the present invention can also be applied to a roll stamping method corresponding thereto. The roll stamping method of the present invention is a method in which a material to be continuously fed is fed into a plurality of rolls 10, 20, 40, 50 through a stamping structure formed on the outer surface of the roller set 10, And a cutting step of cutting the molded workpiece, wherein a portion of the workpiece is changed from a first shape to a second shape by passing through the plurality of shaping steps, (And passing through the last set of rollers 40 after passing the forming roller set 50) opposite to the deformation direction in which the first set of rollers 50 is deformed from the first shape to the second shape.

At this time, if the forming is performed in the direction of deformation that deforms from the first shape to the second shape after the deformation forming step, the residual stress increases in the opposite directions in the transition portions 102 and 103 as in the prior art, , It is advantageous that the deformation forming step is carried out at least after the middle of the entire forming step, and the molding with which the residual stress is increased again after the reverse deformation forming is small.

It is also possible to reduce the residual stress of the transition portions 102 and 103 by increasing or decreasing the length of the forming portion, but it is also possible to reduce the residual stress by changing the shape of the forming portion. For example, it is also possible to reduce the residual stress at the transition portions 102 and 103 by performing reverse bending at the transition portions 102 and 103 in the final forming step.

5 and 6 show a final shape of the product by the roll stamping apparatus of the present invention and a top view showing the work shape to be formed in the over-molding roller set, respectively.

5 and 6, the forming area length L2 of the second roller set is shorter than the forming area length L3 of the over-molding roller set (L2 < L3).

5, the lengths L2b and L3b of the transitions 102 and 103 are the same after passing through the second roller set and after passing through the over-molding roller set (L2b = L3b) The lengths L2a and L3a of the forming roller set are long and the length of the flat portion 101 of the forming roller set is long (L3a> L2a). That is, in the over-molding roller set, the length of the flat portion 101 is increased without changing the shapes of the transition portions 102 and 103, thereby forming the material in such a manner that the length of the entire forming region is extended. The transition portions 102 and 103 are moved again from the final roller set 40 to the target forming length L4, and the inverse forming occurs in the process.

6, the lengths L3a and L2a of the flat portion 101 are the same after passing the second roller set and after passing through the over-molding roller set (L2a = L3a) The sum of the lengths L2b and L3b of the forming roller set and the lengths of the transition portions 102 and 103 of the forming roller set is long (ΣL3a> ΣL2a).

And the forming roller set form the material in such a manner that the length of the entire forming region is extended by increasing the length of the transition portions 102 and 103 without changing the shape of the flat portion 101, A part of the transition portions 102 and 103 becomes the return portions 105 and 106 (see FIG. 4) while returning to the target forming length L4 from the roller set 40 again, .

Fig. 7A shows a photograph of a workpiece molded by a conventional roll stamping apparatus. As shown in Fig. 7A, the material is not attached to the floor and is twisted. That is, when the material is formed by the conventional roll stamping apparatus, distortion occurs in the material due to the residual stress in the opposite directions in the plurality of transition portions.

Fig. 7B shows a photograph of the material formed by the roll stamping apparatus according to the present invention. As shown in FIG. 7B, the material is formed by the roll stamping apparatus according to the present invention, so that it can be confirmed that the material is attached to the floor without distortion.

Figures 8 and 9 show a roll stamping apparatus of another embodiment of the present invention.

Other embodiments of FIGS. 8 and 9 include roller sets 10, 20, 40 and 50 having the same molding part as the embodiment shown in FIG. 3, (15a, 15b, 25a, 25b, 45a, 45b, 55a, 55b) on the surface opposite to the surface of the substrate.

In this embodiment, the escaping portions 15a, 15b, 25a, 25b, 45a, 45b, 55a and 55b are formed inwardly from the circumference of the roll, As shown in Fig.

As shown in FIG. 9, the roller sets 10, 20, 40, and 50 are arranged such that the escaping portions 15a, 15b, 25a, 25b, 45a, 45b, 55a, At this time, the material S passing through the roller sets 10, 20, 40, and 50 can pass without any shaping. Since the escape portions 15a, 15b, 25a, 25b, 45a, 45b, 55a and 55b are formed in a certain region on the outer periphery of the roller, molding may not be performed in a certain section of rotation of the roller.

In this embodiment, the roller sets 10, 20, 40 and 50 are formed with the escaping portions 15a, 15b, 25a, 25b, 45a, 45b, 55a, and 55b together with the forming portions 11a, 11b, 41a, 41b, 51a, 55b are formed, the material S is formed in a certain section, and the material S can be bypassed in a certain section.

Particularly, when the escape portions 15a, 15b, 25a, 25b, 45a, 45b, 55a and 55b are opposed to each other, they do not contact the roller set 10, 20, 40, 50 and the material S, S can be moved faster during molding, and therefore, even when the interval between the sections L4 and L6 (see Fig. 10) to be molded is changed, molding can be performed without changing the roller set.

Fig. 10 shows the material S formed according to the embodiment of Figs. 8 and 9. Fig. The formed sections L4 and L6 are set such that the revolution speed rev / min of the roller sets 10, 20, 40 and 50 is constant when the feed speed m / min of the material S is constant, But the rotation speed of the roller set 10, 20, 40, 50 is slow or fast when the non-inflated, especially the escape portions 15a, 15b, 25a, 25b, 45a, 45b, 55a, The lengths of the non-forming sections L5 and L7 can be adjusted. That is, by making the ratio of the feed speed of the material at the time of forming and the rotational speed of the roller set different from the feed speed of the material at the time of non-forming and the rotational speed of the roller set, have.

Accordingly, it is also possible to manufacture parts having various lengths of the roll forming parts of this embodiment. Particularly, in the case of a structure such as a door impact beam having a constant section and a variable length, a door impact beam of various doors can be formed by one roll stamping apparatus.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

10, 20, 30, 40: roller set 50: and deformation roller set
11a, 11b, 41a, 41b, 51a, 51b:
15a, 15b, 25a, 25b, 45a, 45b, 55a, 55b:
101: flat portion 102, 103: transition portion
105, and 106:

Claims (9)

A roller set which rotates while facing each other so as to press the both sides of the continuously supplied material while advancing the roller set, a forming part to which a stamping structure is applied to the outer surface of the roller set to form the material, And an escape portion,
A plurality of roller sets are disposed along a material advancing direction,
Each of the forming portions of the roller set is formed so as to sequentially change the cross-section of the material in accordance with the progress of the material,
The forming portion of at least one of the roller sets before the final roller set through which the material passes last is a set of forming rollers having a longer circumferential length than the forming portion of the final roller set,
And a roller set for forming a material in a direction opposite to a direction in which the material is deformed in the over-molding roller set after the over-molding roller set.
The method according to claim 1,
Wherein the overforming roller set is disposed within at least three of the last set of rollers.
3. The method of claim 2,
The forming unit
Wherein an engraved angle of both sides of the outer surface of one of the roller sets is opened and an embossed angle corresponding to the engraved angle of the outer surface of the other rotary roll.
3. The method of claim 2,
The forming unit of the roller set is formed to sequentially planarize by removing concave /
Wherein the shaping portion of the final roller set and the overmoulding roller set includes a flat portion that is flat in the width direction and has a predetermined length in the circumferential direction and a transition portion that is positioned on both sides of the flat portion in the circumferential direction,
Wherein the circumferential length of the flat portion of the over-molding roller set is longer than the circumferential length of the flat portion of the final roller set.
3. The method of claim 2,
Wherein the forming portion of the over-molding roller set includes a flat portion that is flat in the width direction and has a predetermined length in the circumferential direction, and a transition portion that is positioned on both sides of the flat portion in the circumferential direction,
Wherein the circumferential length of the transition portion of the overmoulding roller set is longer than the circumferential length of the transition portion of the final roller set.
The method according to claim 1,
And the escaping portion is formed on the opposite side of the forming portion.
The method according to claim 6,
Wherein the escaping portion is recessed radially inwardly from an outer peripheral surface of the roller.
A roll stamping method for roll stamping using the roll stamping apparatus according to any one of claims 1 to 7,
A primary shaping step of shaping the material into a molded part of the roller set;
A bypass step of passing the material through an escape portion of the roller set to bypass the material;
A secondary forming step of re-forming the material into a molded part of the roller set; And
And a deformation-shaping step of shaping the workpiece in a direction opposite to a direction in which the workpiece is deformed in the primary shaping step and the secondary shaping step
/ RTI &gt;
9. The method of claim 8,
Wherein the ratio of the feed rate of the material to the rotational speed of the roller set is different from each other in the first molding step and the bypass step.

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