A device for unfolding a shaped metal article and a method for unfolding the same

Abstract: In a device and method for unfolding a shaped metal article (1) having a longitudinal bent or curved portion (1f-1k), the shaped metal article (1) is unfolded along the bent or curved portion (1f-1k). The device is provided with a vacuum-type absorbing means (3d-3f) for absorbing at least one side (1a-1e) of the shaped metal article (1) adjacent to the bent or curved portion (1f-1k). The one side of the shaped metal article (1) is unfolded against the other side of the shaped metal article about the bent or curved portion (1f-1k).

Description: The present invention relates to a device for unfolding a shaped metal article having at least a longitudinal bent or curved portion such that the shaped metal article is unfolded along the bent portion and a method for unfolding the same, according to the preambles of claims 1 and 6 respectively. Aluminum extruded articles have been widely used as various kinds of structural materials because of advantages such as lightness, high productivity and low cost. As a result, it has recently been required that extruded articles having a wide width have been also formed as aluminum extruded articles. Such an aluminum extruded article is obtained by extruding a billet through a forming slit formed in a die member. To obtain a wide extruded article, a die member, a container and a billet must be large, in accordance with the width of the extruded article. Thus, there will be a certain limitation in enlarging them. It is, therefore, impossible to extrude a wide article having more than a certain width. To cope with the above-mentioned problems, a method for obtaining a wide structural material has been proposed in US-A-2 802 509, on which the preambles of claims 1 and 6 are based. The method includes the steps of extruding an aluminum article having a longitudinal bent or curved portion. In the method, the opening angle of the bent or curved portion is gradually enlarged by using a rolling mill. In the unfolding method mentioned above, however, a roll must be replaced with another roll having a larger opening angle after each unfolding step. Thus, it takes a lot of labor to change rolls. Furthermore, one passing of a roll often may not be enough to unfold the article to a certain opening angle, thus several passings of rolls may be required. Therefore, even in each unfolding step, it takes a lot of time to unfold it. Under the circumstances, the unfolding steps of this method are not performed at a high efficiency. An object of the present invention is, therefore, to provide a device and a method for unfolding a shaped metal article having a longitudinal bent or curved portion such that the shaped metal article is unfolded along the bent or curved portion at a high efficiency, and in particular to provide a new device and method as an alternative to a conventional rolling mill and rolling method. Other objects and advantages of the present invention will become apparent from the description contained herein. It should be recognized that the examples are to describe preferred embodiments of the present invention. Accordingly, the invention is not limited to the examples and various modifications are possible within the scope of the appended claims. According to one aspect of the present invention, this object is achieved by a device for unfolding a shaped metal article having at least a longitudinal bent or curved portion (hereinafter referred to as a bent portion) such that the shaped metal article is unfolded along the bent portion, characterized by a vacuum-type absorbing means for ababsorbing at least one side of the shaped metal article located adjacent to the bent portion and a driving mechanism for moving the absorbing means so as to unfold the one side against the other side of the shaped metal article about the bent portion. Further, according to another aspect of the present invention, this object is achieved by a method for unfolding a shaped article having at least a longitudinal bent or curved portion such that the shaped article is unfolded along the bent portion, characterized by the steps of absorbing at least one side of the shaped metal article adjacent to the bent portion by a vacuum-type absorbing means and driving said absorbing means so as to unfold the one side against the other side of the shaped metal article about the bent portion. Preferred embodiments of the invention are defined in the dependent claims. In the mentioned device and method, since both side portions located at both sides of the bent portion of the shaped metal article is unfolded along the bent portion by moving the vacuum-type absorbing means which absorbs at least one side portion of the shaped article, the shaped article can be unfolded into a desired unfolded shape at high efficiency. Other objects and advantages of the present invention will become apparent from the description of the preferred embodiments, which may be modified in any manner without departing from the scope of the invention, as defined by the appended claims. Figs. 1A to 1C are end views showing unfolding steps of a shaped article by using a device for unfolding the shaped article according to a first embodiment of the present invention. Figs. 2A and 2B show the device for unfolding a shaped article, wherein Fig. 2A is an end view showing absorbing means of the device in the final stage of the unfolding steps, and wherein Fig. 2B is an end view showing absorbing means of the device in the first stage of the unfolding steps. Fig. 3 is a cross-sectional view showing the inner structure of the absorbing means. Fig. 4A is an end view showing a shaped article to be unfolded according to the first embodiment, and Fig. 4B is an end view showing an extruded article to become the shaped material, Fig 4C is an end view showing an unfolded article. Figs. 5A to 5C show a second embodiment of the present invention, wherein Fig. 5A is an end view showing a shaped article in which filler materials are fitted, wherein Fig. 5B is an end view showing the shaped article and vacuum-type absorbing means fitted to the shaped article, and wherein Fig. 5C is an end view showing the shaped article and vacuum-type absorbing means in the final stage of the unfolding steps. Fig. 6A is a perspective view showing the shaped article and a filler material shown in Figs. 5A to 5C in the disassembled state, and Fig. 6B is a perspective view showing the shaped article and the filler material fitted therein. Fig. 7A is a cross-sectional view showing the state of absorbing the shaped article shown in Figs. 6A and 6B by a vacuum-type absorbing means, and Fig. 7B is a cross-sectional view taken along the line 7-7 of Fig. 7A. Figs. 8A to 8C show a revised second embodiment, wherein Fig. 8A shows a perspective view of a shaped article and filler material in an disassembled state, wherein Fig. 8B shows a perspective view of the shaped article and the filler material fitted therein, and wherein Fig. 8C shows a longitudinal cross-sectional view of the shaped article and the filler material fitted therein. Fig. 9A is an end view showing a shaped article to be unfolded according to the second embodiment, and Fig. 9B is an end view showing an extruded article to become the shaped material, and Fig. 9C is an end view of the shaped article in an unfolded state. Figs. 10A and 10B show a third embodiment of the invention, wherein Fig. 10A is an end view showing the shaped article and vacuum-type absorbing means disposed along the shaped article, and wherein Fig. 10B is an end view showing the shaped article and vacuum-type absorbing means in the final stage of the unfolding steps. Fig. 11A is a cross-sectional view showing the inner structure of the absorbing means shown in Fig. 10, and Fig. 11B shows an example of an absorbing circuit for a group of vacuum absorbing means, and Fig. 11C shows another example of an absorbing circuit for a group of vacuum absorbing means. Fig. 12A is an end view showing a shaped article to be unfolded according to the third embodiment, Fig. 12B is an end view showing an extruded article to become the shaped material, and Fig. 12C is an end view showing an unfolded article. Fig. 13 shows a revised third embodiment of the present invention, wherein Fig. 13A is an end view showing the shaped article and vacuum-type absorbing means disposed along the shaped article, and wherein Fig. 13B is an end view showing the shaped article and vacuum-type absorbing means in the final stage of the unfolding steps. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments according to the present invention will now be described in detail, with reference to the accompanying drawings. (First embodiment) A shaped article to be unfolded is a cylindrical aluminum extruded article 1 having a pentagonal cross-section. As shown in Fig. 4A, the shaped article 1 comprises five flat portions, i.e., a first flat portion 1a , a second flat portion 1b connected to the first flat portion 1a by a bent portion 1f , a third flat portion 1c connected to the second flat portion 1b by a bent portion 1g , a fourth flat portion 1d connected to the third flat portion 1c by a bent portion 1h and a fifth flat portion 1e connected to the fourth flat portion 1e by a bent portion 1i . The first flat portion 1a and the fifth flat portion 1e are not connected but are divided by a slit s formed therebetween. The shaped article 1 is formed by extruding a hollow extruded article 1 having an imitation portion i formed on one of five vertexes as shown in Fig. 4B and then removing the imitation portion i . The length of the shaped article 1 is, for example, about 20 meters or so. A device for unfolding the shaped article 1 according to this embodiment is designed so as to unfold the shaped article 1 into a flat unfolded article P as shown in Fig. 4C. In Fig. 2, showing the device for unfolding a shaped article, the numerals 3a , 3b , 3c , 3d , 3e denote a first to fifth absorbing means, respectively. The device is equipped with a driving mechanism 4' for drive the first to fifth absorbing means 3a , 3b , 3c , 3d , 3e to act unfolding operations. The first to fifth absorbing means 3a , 3b , 3c , 3d , 3e are provided in accordance with the first to fifth flat portion 1a , 1b , 1c , 1d , 1e of the shaped article 1 . Each absorbing means 3a , 3b , 3c , 3d , 3e is designed to absorb an outer surface of the corresponding flat portion 1a , 1b , 1c , 1d , 1e of the shaped article 1 . Each absorbing means 3a , 3b , 3c , 3d , 3e has a rectangular absorbing portion 5 having a length approximately equal to the length of the shaped article 1 and a width approximately equal to the width of each corresponding flat portion 1a , 1b , 1c , 1d , 1e , as shown in Fig. 1B, so as to hold the shaped article 1 by absorbing (i.e., vacuum suctioning) approximately the whole area of the outer surfaces of the flat portions 1a , 1b , 1c , 1d , 1e because of the following reasons. One of the reasons is to hold the shaped article 1 with sufficient absorbing force of each absorbing means 3a , 3b , 3c , 3d , 3e during the unfolding operations by keeping as large an absorbing area as possible. The other reason is to enable effective plastic transformation to the bent portions 1f , 1g , 1h , 1i of the shaped article 1 by absorbing each flat portion 1a , 1b , 1c , 1d , 1e including an area adjacent to the bent portions 1f , 1g , 1h , 1i . Each absorbing means 3a , 3b , 3c , 3d , 3e may be divided along the length of the shaped article 1 into a plurality of divided absorbing means to vacuum absorb each flat portion 1a , 1b , 1c , 1d , 1e of the shaped article 1 . By dividing the absorbing means as mentioned above, various lengths of shaped articles can be unfolded by adjusting the number of the divided absorbing means to be positioned along the length of the shaped article 1 . As shown in Fig. 3, each absorbing means 3a , 3b , 3c , 3d , 3e includes a vacuum chamber 6 which opens toward an absorbing portion 5 . The vacuum chamber 6 is divided by a partition 7 into an outside chamber 6a located toward the absorbing portion 5 and an inside chamber 6b . The partition 7 is placed such that the outside chamber 6a has a shallow bottom and the inside chamber 6b has a large volume. A communication port 9 is formed in the partition 7 so as to communicate the outside chamber 6a with the inside chamber 6b . A vacuuming device 10 , such as a vacuum pump, is connected to the inside chamber 6b such that the inside chamber 6b and the outside chamber 6a are decompressed to absorb the flat portions 1a , 1b , 1c , 1d , 1e of the shaped article 1 . The above structure of the vacuum chamber 6 which is divided into two divisional chambers 6a , 6b is designed to attain a smooth absorbing operation. A packing, or sealing, ring 11 is disposed around the inner peripheral portion of the outside chamber 6a . As mentioned above, the driving mechanism 4 is used to drive the above mentioned five absorbing means 3a , 3b , 3c , 3d , 3e and to change their positions between two positions, i.e., a first position and a second position, as shown in Fig. 2. In the first position, i.e., an opened position, five absorbing means 3a , 3b , 3c , 3d , 3e stand in row with each absorbing portion 5 facing up, as shown in Fig. 2A. In the second position, i.e., a closed position, each absorbing means 3a , 3b , 3c , 3d , 3e is positioned on each side of an equilateral pentagon, as shown in Fig. 2B. To change the positions from the opened position to the closed position, the second and fourth absorbing means 3b , 3d each adjacent to the central absorbing means, i.e., third absorbing means 3c , are rotated by 72 degrees against the third absorbing means 3c , respectively, and the first and fifth absorbing means 3a , 3e each adjacent to the second and fourth absorbing means 3b , 3d , respectively, are rotated by 72 degrees against the second and forth absorbing means 3b , 3d , respectively. Changing the positions from the closed position to the opened position can be done in a manner opposite to the above. The working of the driving mechanism 4' can be performed by synchronously operated gear mechanisms, or the like, each located at both ends of each absorbing means 3a , 3b , 3c , 3d . In the device for unfolding a shaped article, the shaped article 1 will be unfolded as follows. In an opened position of the absorbing means 3a , 3b , 3c , 3d , 3e , a third flat portion 1c of the shaped article 1 is placed on the third absorbing means 3c with the slit portion s facing up, as shown in Fig. 1A. Thereafter, as shown in Fig. 1B, the first to fifth absorbing means 3a , 3b , 3c , 3d , 3e are moved from the opened position to the closed position so as to fit each absorbing portion 5 of the first to fifth absorbing means 3a , 3b , 3c , 3d , 3e on the corresponding outer surface of the first to fifth flat portion 1a , 1b , 1c , 1d , 1e of the shaped article 1 . Then, each absorbing means 3a , 3b , 3c , 3d , 3e absorbs to hold the outer surface of each flat portion 1a , 1b , 1c , 1d , 1e . Thereafter, as shown in Fig. 1c, the first to fifth absorbing means 3a , 3b , 3c , 3d , 3e are driven toward their opened position. As a result, the second and forth flat portions 1b , 1d are unfolded by 72 degrees against the third flat portion 1c about the bent portions 1g , 1h , respectively, and the first and fifth flat portions 1a , 1e are unfolded by 72 degrees against the second and forth flat portions 1b , 1d about the bent portions 1f , 1i , respectively. Thus, the above mentioned equilateral pentagonal hollow aluminum extruded article 1 having a slit s along the length thereof is unfolded into a wide flat plate-like unfolded article P . Thereafter, the vacuum-absorbing operation is released to detach the unfolded article P , and then next shaped article 1 to be unfolded is set in the same manner as mentioned above. As clearly understood form the above explanation, in the device for unfolding a shaped article 1 mentioned above, a vacuum-type absorbing means 3c absorbs to hold, i.e., applies suction to, one side portion 1c adjacent to a bent portion 1g of a shaped article 1 , and a vacuum-type absorbing means 3b absorbs to hold the other side portion 1b adjacent to the bent portion 1g , and then each absorbing means 3b , 3c is driven to unfold both side portions 1b , 1c of the shaped article 1 about the bent portion 1g . Therefore, a shaped metal article 1 having a longitudinal bent portion 1g can be unfolded at high efficiency by the device. The device can be effectively used to roughly unfold a shaped article. Further, each absorbing means 3a , 3b , 3c , 3d , 3e has a rectangular absorbing portion 5 having a length approximately equal to the length of the extruded shaped article 1 and a width approximately equal to the width of each flat portion 1a , 1b , 1c , 1d , 1e of the extruded shaped article 1 so as to absorb and hold almost the whole area of the outer surface of each flat portion 1a , 1b , 1c , 1d , 1e of the extruded shaped article 1 . Therefore, during the unfolding procedures, each absorbing means 3a , 3b , 3c , 3d , 3e can hold the article 1 with enough absorbing force by keeping as large absorbing area as possible, and can enable effective plastic transformation to the bent portion 1f , 1g , 1h , 1i of the shaped article 1 by absorbing each flat portion 1a , 1b , 1c , 1d , 1e including an area adjacent to the bent portion 1f , 1g , 1h , 1i . As a result, an effective unfolding processing can be performed. Further, in this embodiment, the shaped article 1 to be unfolded is a shaped article having a plurality of longitudinal bent portions 1f , 1g , 1h , 1i and the number of the vacuum absorbing means 3a , 3b , 3c , 3d , 3e corresponds to the number of flat portions 1a , 1b , 1c , 1d , 1e . And each flat portion 1a , 1b , 1c , 1d , 1e of the shaped article 1 is simultaneously unfolded by the absorbing means 3a , 3b , 3c , 3d , 3e each absorbing a corresponding flat portion 1a , 1b , 1c , 1d , 1e . Therefore, the shaped article 1 can be unfolded into a flat plate by one unfolding operation with high efficiency, as compared to a conventional unfolding operation in which each bent portion 1f , 1g , 1h , 1i is unfolded one after the other. Because the device is designed to unfold a shaped article 1 by vacuum absorbing, even if the shaped article 1 is a hollow article having a longitudinal slit s , the device can firmly hold flat portions on both sides of a bent portion. Thus, the shaped article 1 can be unfolded by this device without having a complex mechanism and structure. Though the above embodiment is shown as one of the preferred embodiments, the present invention is not limited to the above embodiment and as would be apparent to those skilled in the art, various substitutions and modifications within the scope and spirit of the invention are contemplated. For example, in the above mentioned embodiment, though the shaped article to be unfolded is a pentagonal cylindrical shaped article and the device is provided with five vacuum absorbing means corresponding to the number of flat portions, the device may be provided with two vacuum absorbing means to unfold each bent portion of the shaped article one after the other. Further, the device may be provided with one vacuum absorbing means for absorbing one flat portion and a holding means other than a vacuum absorbing means for holding the other flat portion. Furthermore, a shaped article to be unfolded by the device is not limited to the above if the article has at least one longitudinal bent portion. Such a bent portion may be a V-shaped or a U-shaped portion. In the embodiment mentioned above, the shaped article is shown as an extruded shaped article, but various kinds of articles other than extruded articles can be applied. In the above mentioned embodiment, every bent portion of the shaped article is completely unfolded, but each bent portion may be unfolded so as to have a certain angle. In the above mentioned embodiment, each absorbing means 3a , 3b , 3c , 3d , 3e is formed to be one piece along the length of the article, but each absorbing means 3a , 3b , 3c , 3d , 3e may be divided along the length of the article into a plurality of separate absorbing means. As mentioned above, the device according to the above mentioned embodiment includes a vacuum-type absorbing means for absorbing one side portion located at one side of the bent portion, a vacuum-type absorbing means for absorbing the other side portion located at the other side of the bent portion and a driving means for moving the absorbing means such that the side portions each absorbed by the absorbing means are moved to be unfolded along the bent portion. Therefore, by moving each vacuum-type absorbing mean which absorbs each side portion of the shaped metal article to unfold them along the bent portion, the shaped metal article can be unfolded to be a desired unfolded shape with a high efficiency. The method for unfolding a shaped article can attain the same effects as mentioned above. (Second embodiment) A shaped article to be unfolded is a cylindrical aluminum extruded article having a hexangular cross-section. As shown in Fig. 9A, the shaped article 1 comprises six side portions, i.e., a first side portion 1a , a second side portion 1b connected to the first side portion 1a by a bent portion 1g , a third side portion 1c connected to the second side portion 1b by a bent portion 1h , a fourth side portion 1d connected to the third side portion 1c by a bent portion 1i , a fifth side portion 1e connected to the fourth side portion 1d by a bent portion 1j and a sixth side portion 1f connected to the fifth side portion 1e by a bent portion 1k . The first side portion 1a and the sixth side portion 1f are not connected, but are divided by a slit s formed therebetween. Each side portion 1a , 1b , 1c , 1d , 1e , 1f has, at its central portion in the direction of the width, an inwardly dented portion 2 formed along the whole length of the side portion for fixing a bolt, or the like. Each dented portion 2 is formed to be a trapezoidal shape in cross-section having inclined side portions 2a widening toward the bottom portion 2b . The shaped extruded article 1 is formed by extruding a hollow extruded article 1 having a hexangular shape in cross section and having an imitation portion i formed on one of six vertexes as shown in Fig. 9B and then removing the imitation portion i . The length of the shaped article 1 is, for example, about 20 meters or so. A device for unfolding the shaped article 1 according to this embodiment is designed so as to unfold the shaped article 1 into a flat unfolded article P as shown in Fig. 9C. A seal member 4 is of a trapezoidal shape in cross section which corresponds to the cross-section of the dented portion 2 so as to be closely fitted in the dented portion 2 , as shown in Figs. 6A and 6B. Each seal member 4 is made of an elastic material such as rubber or soft resin. Each seal member 4 has a length corresponding to the length of the shaped article 1 to be fitted in the dented portion 2 of the shaped article 1 along the whole length thereof. As shown in Figs. 5B and 5C, the device for unfolding the shaped article 1 mentioned above is a vacuum-type device and is equipped with six absorbing means, i.e., the first to sixth vacuum-type absorbing means 3a , 3b , 3c , 3d , 3e , 3f and driving mechanism 4' for driving these absorbing means (not shown) to conduct the unfolding operation. The first to sixth absorbing means 3a , 3b , 3c , 3d , 3e , 3f are provided in accordance with the first to sixth side portion 1a , 1b , 1c , 1d , 1e , 1f of the shaped article 1 . Each absorbing means 3a , 3b , 3c , 3d , 3e , 3f is designed to absorb an outer surface of the corresponding side portion 1a , 1b , 1c , 1d , 1e , 1f of the shaped article 1 . Since the structure of each absorbing means 3a , 3b , 3c , 3d , 3e , 3f is the same as the absorbing means of the first embodiment shown in Fig. 3, an explanation thereof is omitted. As mentioned above, the driving mechanism 4' is used to move the above mentioned six absorbing means 3a , 3b , 3c , 3d , 3e , 3f and to change their positions between two positions, i.e., a first position and a second position. In the first position, i.e., an opened position, six absorbing means 3a , 3b , 3c , 3d , 3e , 3f stand in row with each absorbing portion 5 facing up. In the second position, i.e., a closed position, each absorbing means 3a , 3b , 3c , 3d , 3e is positioned on each side of a hexagon. To change the positions from the opened position to the closed position, the second and fourth absorbing means 3b , 3d each adjacent to the central absorbing means, i.e., third absorbing means 3c , are rotated by 60 degrees against the third absorbing means 3c , respectively, and the second and fifth absorbing means 3a , 3e each adjacent to the second and fourth absorbing means 3b , 3d , respectively, are rotated by 60 degrees against the second and fourth absorbing means 3b , 3d , respectively, and that the sixth absorbing means 3f is rotated by 60 degrees against the fifth absorbing means 3e . Changing the positions from the closed position to the opened position can be done in a manner opposite to the above. The working of the driving mechanism 4 can be performed by synchronously operated gear mechanisms, or the like, each located at both ends of each absorbing means 3a , 3b , 3c , 3d , 3e , 3f . In the device for unfolding a shaped article, the shaped article 1 will be unfolded as follows. As shown in Figs. 5A, 6A and 6B, the seal members 4 are fitted in the dented portions 2 of the shaped article 1 . Since the seal member 4 is made of an elastic material such as rubber or soft resin, the seal member 4 can be easily fitted in the dented portion 2 because of its elasticity. Next, the shaped article 1 is set in the device. That is, in an opened position of the absorbing means 3a , 3b , 3c , 3d , 3e , 3f , a third flat portion 1c of the shaped article 1 is placed on the absorbing portion 5 of the third absorbing means 3c with the slit portion s facing up. Thereafter, as shown in Fig. 5B, the first to sixth absorbing means 3a , 3b , 3c , 3d , 3e , 3f are moved from the opened position to the closed position so as to fit each absorbing portion 5 of the first to sixth absorbing means 3a , 3b , 3c , 3d , 3e , 3f on corresponding outer surface of the first to sixth flat portion 1a , 1b , 1c , 1d , 1e , 1f of the shaped article 1 with each absorbing means 3a , 3b , 3c , 3d , 3e , 3f crossing over each dented portion 2 . Then, each absorbing means 3a , 3b , 3c , 3d , 3e , 3f absorbs to hold the outer surface of each flat portion 1a , 1b , 1c , 1d , 1e , 1f . As shown in Fig. 7B, a space formed between the absorbing means 3a , 3b , 3c , 3d , 3e , 3f and the side portion 1a , 1b , 1c , 1d , 1e , 1f is filled up with the seal member 4 . Therefore, each side portion 1a , 1b , 1c , 1d , 1e , 1f can be firmly absorbed and held by each absorbing means 3a , 3b , 3c , 3d , 3e , 3f , even if each absorbing means 3a , 3b , 3c , 3d , 3e , 3f is placed on each side portion 1a , 1b , 1c , 1d , 1e , 1f with each absorbing means 3a , 3b , 3c , 3d , 3e , 3f crossing over each dented portion 2 . Especially, since a seal member 4 made of elastic materials such as rubber or soft resin is closely fitted in the dented portion 2 of the shaped article 1 , an excellent sealing performance can be obtained by the elasticity of the seal member 4 , and, therefore, the shaped article 1 can be firmly held by the absorbing means. Thereafter, as shown in Fig. 5C, the first to sixth absorbing means 3a , 3b , 3c , 3d , 3e , 3f are driven toward their opened position. As a result, the second and fourth side portions 1b , 1d are unfolded by 60 degrees against the third flat portion 1c about the bent portions 1h , 1i , respectively, and the first and fifth flat portions 1a , 1e are unfolded by 60 degrees against the second and fourth side portions 1b , 1d about the bent portions 1g , 1j , respectively, and the sixth side portion 1f is unfolded by 60 degrees against the fifth side portion 1e about the bent portions 1k . Thus, the above mentioned extruded article 1 is unfolded into a wide flat plate-like unfolded article P . Thereafter, the vacuum-absorbing operation is released to detach the unfolded article P and the seal member 4 is removed from the unfolded article P . Though the second embodiment according to the present invention is described above, the present invention is not limited to that above. In the above mentioned embodiment, the seal member 4 is fitted in the dented portion 2 of the shaped article 1 along the whole length thereof, but as shown in Figs. 8A to 8C, short length seal members 4 may be partially fitted in the dented portion 2 so as to enable vacuum absorbing. The cross-sectional shape of the dented portion 2 of the shaped article 1 is not specifically limited, and may be modified into various kinds of shapes. In the second embodiment, the hollow shaped article 1 having an hexagonal cross-section is to be unfolded by six vacuum-type absorbing means 3a , 3b , 3c , 3d , 3e , 3f corresponding to the first to sixth side portions 1a , 1b , 1c , 1d , 1e , 1f . However, each bent portion 1g , 1h , 1i , 1j , 1k may be unfolded one after the other by a pair of vacuum-type absorbing means. Further, a shaped article to be unfolded is not limited to the above. The shaped article may comprise a pair of side portions, a bent portion connecting the side portions and a dented portion formed on at least one of the side portions. Furthermore, a shaped article may be a V-shaped article which includes a pair of side portions and a bent portion connecting them. In the method for unfolding a shaped article according to the second embodiment, the method includes the steps of fitting a seal member in a dented portion formed on a side portion before placing a vacuum absorbing means on a side portion with the absorbing means crossing over the dented portion, and absorbing the side portion by the absorbing means with the absorbing means crossing over the dented portion. Since a space formed between the absorbing means and the side portion of the shaped article is sealed by the seal member, the absorbing means can firmly hold the side portion even if the absorbing means is placed on the side portion with the absorbing means crossing over the dented portion. As a result, even if a shaped metal article has a dented portion formed on an outer surface of at least one of the side portions, the shaped metal article can be unfolded by the vacuum absorbing method. Adapting an elastic material as a seal member can enhance sealing performance and reliability of unfolding procedures. (Third embodiment) In the third embodiment, a shaped article to be unfolded is a cylindrical aluminum extruded article having a hexangular cross-section. As shown in Fig. 12, the shaped article 1 comprises six side portions, i.e., a first side portion 1a , a second side portion 1b connected to the first side portion 1a by a bent portion 1g , a third side portion 1c connected to the second side portion 1b by a bent portion 1h , a fourth side portion 1d connected to the third side portion 1c by a bent portion 1i , a fifth side portion 1e connected to the fourth side portion 1d by a bent portion 1j and a sixth side portion 1f connected to the fifth side portion 1e by a bent portion 1k . The first side portion 1a and the sixth side portion 1f are not connected, but divided by a slit s formed therebetween. As shown in Figs. 10A and 10B, the device for unfolding the shaped article 1 mentioned above is equipped with a first group of three vacuum-type absorbing means 3a , 3b , 3c and a second group of three vacuum-type absorbing means 3d , 3e , 3f . The first group of three vacuum-type absorbing means 3a , 3b , 3c is designed to absorb an outer surface of one of the side portions adjacent to the bent portion 1g of the shaped article 1 and the second group of three vacuum-type absorbing means 3d , 3e , 3f is designed to absorb an outer surface of the other of the side portions adjacent to the bent portion 1g of the shaped article 1 . Each vacuum-type absorbing means 3a , 3b , 3c in the first group has a length approximately corresponding to the length of the shaped article 1 and a width of approximately one third of the length of the width of a side portion of the shaped article 1 so that each absorbing means 3a , 3b , 3c can absorb corresponding area of the outer surface of the side portion and three of them can absorb almost the whole area of the outer surface of the side portion. The same thing can be said of the second group of three absorbing means 3d , 3e , 3f . Since the structure of each absorbing means 3a , 3b , 3c is the same as the absorbing means of the first embodiment shown in Fig. 3, an explanation thereof is omitted. As shown in Fig. 11B, a separate vacuum pump P may be connected to each vacuum-type absorbing means 3a , 3b , 3c of the first group, or, as shown in Fig. 11C, one vacuum pump P may be connected to each vacuum-type absorbing means 3a , 3b , 3c of the first group by way of a switching valve V . The same thing can be said of the second group of the absorbing means 3d , 3e , 3f . As shown in Figs. 10A and 10B, the first group of three vacuum-type absorbing means 3a , 3b , 3c is held so as to move together for unfolding operations and also the second group of three vacuum-type absorbing means 3d , 3e , 3f is held so as to move together for unfolding operations. The first group of three vacuum-type absorbing means 3a , 3b , 3c and the second group of three vacuum-type absorbing means 3d , 3e , 3f are relatively driven for unfolding operations by a driving mechanism (not shown). The relative working of the absorbing means can be performed by synchronously operated gear mechanism, or the like, each located at both ends of each absorbing means 3a , 3b , 3c and 3d , 3e , 3f . The shaped article 1 will be unfolded as follows. As shown in Fig. 10A, in the event that the side portions 1a , 1b located at both sides of the bent portion 1g are unfolded about the bent portion 1g , the first group of three vacuum-type absorbing means 3a , 3b , 3c is placed on the outer surface of the first side portion 1a and the second group of three vacuum-type absorbing means 3d , 3e , 3f is placed on the outer surface of the second side portion 1b . Then, vacuum absorbing is performed to vacuum absorb the side portions 1a , 1b . Since one side portion 1a is divided into three areas and each area is vacuum absorbed by the vacuum-type absorbing means 3a , 3b , 3c , respectively, each absorbing area of each vacuum-type absorbing means 3a , 3b , 3c is approximately one third of the area of the side portion 1a , thereby enabling firm vacuum absorbing of the side portion 1a without absorbing ambient air even in the case that the flatness of the outer surface of the side portion 1a is low and/or the side portion 1a is twisted. Furthermore, because almost the whole area of the side portion 1a is absorbed by three vacuum-type absorbing means 3a , 3b , 3c , these three vacuum-type absorbing means 3a , 3b , 3c can firmly hold the side portion 1a with a strong vacuum absorbing force. As for the side portion 1b , the same thing can be said. Thereafter, as shown in Fig. 10B, the first group of three vacuum-type absorbing means 3a , 3b , 3c is relatively moved against the second group of three vacuum-type absorbing means 3d , 3e , 3f such that the side portions 1a , 1b are unfolded about the bent portion 1g and become flat. Because both groups of the vacuum-type absorbing means 3a , 3b , 3c , 3d , 3e , 3f firmly absorb the side portions 1a , 1b , proper unfolding operations can be performed. By unfolding the remaining bent portions 1h , 1i , 1j , 1k one after the other in the same manner as mentioned above, a wide flat article is obtained. Figs. 13A and 13B show another variation of the latter embodiment. In this embodiment, a shaped article to be unfolded is a cylindrical extruded article having a rectangular cross-section. The shaped article 1 has both side portions 1b , 1c each having a stepped outer surface 14 and a bent portion 1h located between the side portions 1b , 1c . In the case of the above-mentioned shaped article, as shown in Fig. 13A, the stepped outer surfaces 14 of one side portion 1b are vacuum absorbed by the first group of a plurality of vacuum-type absorbing means 3a , 3b , 3c and the stepped outer surfaces 14 of the other side portion 1c are vacuum absorbed by the second group of a plurality of vacuum-type absorbing means 3d , 3e , 3f . Then, as shown in Fig. 13B, by relatively moving the first group of the vacuum-type absorbing means 3a , 3b , 3c and the second group of the vacuum-type absorbing means 3d , 3e , 3f , both side portions 1b , 1c can be unfolded about the bent portion 1h . As will be apparent from the above, the above mentioned vacuum-type absorbing means can be applied to various kinds of shaped articles. Though the third embodiment according to the present invention is described above, the present invention is not limited to the above. In the above mentioned embodiment, three divided areas of the side portion of the shaped article are absorbed by three absorbing means, respectively, however, the number of areas to be divided is not limited to three. The outer surface of the side portion of the shaped article may be divided into a plurality of areas along the length thereof and each area may be separately absorbed by a vacuum-type absorbing means, or the outer surface of the side portion of the shaped article may be divided into a plurality of areas along the length and width thereof and each area may be separately absorbed by a vacuum-type absorbing means. In the above mentioned embodiment, a group of a plurality of vacuum-type absorbing means absorbs an outer surface of the side portion of the shaped article, but one vacuum-type absorbing means having a plurality of vacuum-type absorbing portions may absorb an outer surface of the side portion of the shaped article. Furthermore, in the above mentioned embodiment, each bent portion is unfolded one after the other by the first and second vacuum-type absorbing means, but the shaped article may be unfolded in one operation by a plurality of groups of vacuum-type absorbing means corresponding to the side portion of the shaped article. Or, one side portion may be absorbed by one group of vacuum-type absorbing means, and the other side portion may be held by means other than vacuum-type absorbing means. As mentioned above, in the method for unfolding a shaped article according to the third embodiment, because an outer surface of a side portion is divided into a plurality of areas and separate vacuum-type absorbing means absorbs each area, each absorbing area becomes small, thereby enabling firm vacuum absorbing of an outer surface of the side portion by restraining or restricting absorbing ambient air even if flatness of an outer surface of a side portion is low and/or the side portion is twisted. Further, because an outer surface of one side portion is divided into a plurality of areas and each area is to be absorbed, the side portion is vacuum absorbed with a large absorbing area, thereby enabling the absorbing means to hold the outer surface of the side portion with strong absorbing force. Therefore, even in the case that flatness of an outer surface of a side portion of a shaped article is low and/or the shaped article is twisted, procedures for flattening or correcting the shaped article before unfolding procedures can be omitted and proper unfolding procedures can be performed without causing any trouble.

Claims: A device for unfolding a shaped metal article (1) having at least a longitudinal bent or curved portion (1f, 1g, 1h, 1i) such that the shaped metal article (1) is unfolded along the bent portion (1f, 1g, 1h, 1i), characterized by: a vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) for absorbing at least one side of the shaped metal article (1) adjacent to the bent portion (1f, 1g, 1h, 1i); and a driving mechanism (4') for moving said absorbing means (3a, 3b, 3c, 3d, 3e) so as to unfold the one side against the other side of the shaped metal article about the bent portion (1f, 1g, 1h, 1i). The device for unfolding a shaped metal article as recited in claim 1, wherein both sides of the shaped metal article (1) are absorbed by said vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) and said vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) are relatively moved by said driving mechanism (4) so as to unfold both sides of the shaped metal article (1) about the bent portion (1f, 1g, 1h, 1i). The device for unfolding a shaped metal article as recited in claim 1 or 2, wherein the vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) has a vacuum chamber (6) opened toward an absorbing portion (5), the vacuum chamber (6) being divided by an inner partition (7) into an outside chamber (6a) and an inside chamber (6b), both of the chambers (6a, 6b) communicating with each other by way of a communication port (9) formed in the partition (7), and wherein the inner chamber (6b) is connected to a vacuum device (10). The device for unfolding a shaped metal article as recited in claim 3, wherein the outside chamber (6a) has a shallow bottom and the inside chamber (6b) has a large volume. The device for unfolding a shaped metal article as recited in claim 4, further comprising a packing ring (11) disposed around the inner peripheral portion of the outside chamber (6a). A method for unfolding a shaped metal article (1) having at least a longitudinal bent or curved portion (1f, 1g, 1h, 1i) such that the shaped metal article (1) is unfolded along the bent portion (1f, 1g, 1h, 1i), characterized by the steps of: absorbing at least one side of the shaped metal article (1) adjacent to the bent portion (1f, 1g, 1h, 1i) by a vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e);and driving said absorbing means (3a, 3b, 3c, 3d, 3e) so as to unfold the one side against the other side of the shaped metal article (1) about the bent portion (1f, 1g, 1h, 1i) by a driving mechanism (4'). The method for unfolding a shaped metal article as recited in claim 6, wherein both sides of the shaped metal article are absorbed by the vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) and then the vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) is relatively driven so as to unfold both sides of the shaped metal article (1) about the bent portion (1f, 1g, 1h, 1i). The method for unfolding a shaped metal article as recited in claim 6 or 7, wherein the shaped metal article (1) is a polygonal hollow aluminum extruded article having N flat portions connected by the N-1 of bent portions (1f, 1g, 1h, 1i), and the first and Nth of flat portions are adjacent and separated by a slit (S). The method for unfolding a shaped metal article as recited in claim 8, wherein the metal shaped article (1) is formed by extruding an aluminum hollow article having an imitation portion (i) formed on one of N vertexes and then removing the imitation portion. The method for unfolding a shaped metal article as recited in any of claims 6 to 9, wherein the vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) has a vacuum chamber (6) opened toward an absorbing portion, the vacuum chamber (6) being divided by an inner partition (7) into an outside chamber (6a) and an inner chamber (6b), both of the chambers (6a, 6b) communicating with each other by way of a communication port (9) formed in the partition (7), and wherein the inner chamber (6b) is connected to a vacuum device (10) and the absorbing portion of the vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) is placed on a surface of the shaped article (1) and performs the vacuum absorbing operation. The method for unfolding a shaped metal article as recited in claim 10, wherein the outside chamber (6a) has a shallow bottom and the inside chamber (6b) has a large volume. The method for unfolding a shaped metal article as recited in claim 11, wherein a packing ring (11) is disposed around the inner peripherial portion of the outside chamber (6a) so as to seal the vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) and the shaped article (1). The method for unfolding a shaped metal article as recited in any of claims 6 to 9, wherein a side portion of the article (1) having a dented portion (2) is absorbed by a vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) to unfold about the bent portion, a seal member (4) is fitted in the dented portion (2) so as to seal a space formed between the vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) and the side portion; and the vacuum-type absorbing means (3a, 3b, 3c, 3d, 3e) is placed on the side portion with the absorbing means crossing over the dented portion (2). The method for unfolding a shaped metal article as recited in 13, wherein the seal member (4) is made of elastic materials. The method according to any of claims 6 to 14, wherein the side portion of the article (1) adjacent to the bent portion to be absorbed by the vacuum-type absorbing means is divided at an outer surface area thereof and each area is absorbed separately.

Inventors: HIROZO MICHISAKA, KENZO SHITASHIMIZU, SABURO WASHO, YASUO IISAKA
Applicants: SHOWA ALUMINUM CORP, SHOWA ALUMINUM CORPORATION
Application year: 1997
Main classification: B21D1
IPC codes: B21D31, B21D5, B21C37