JP4043550B2 - Bending apparatus and bending method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bending apparatus described in the preceding stage of claim 1 and a bending method for bending an aluminum profile material (profile) in a press. In particular, but not exclusively, the present invention relates to the manufacture of equator profile materials for LNG tanks.
[0002]
[Background Art and Problems to be Solved by the Invention]
The spherical tank used for storing and transporting liquefied gas is large and usually has a diameter of about 40 m. A special profile material is used in the equator region of the large spherical tank, and it must be formed to a desired curvature by press bending. The equator profile material to be bent is usually about 15 m in length, about 1 m in height and has a thickness of about 200 mm, and its weight exceeds 5000 kg. The finished workpiece must meet the requirements for high dimensional accuracy. Because of the dimensions of the workpiece, bending, measurement for inspection, and final control of bending are difficult to implement. In particular, in measurement and bending, it is necessary to consider the springback (elastic deformation recovery) of the workpiece. Also, accurate movement of the workpiece in the press machine is difficult due to its large weight. Furthermore, the equator profile material has an asymmetric cross section with respect to the central horizontal plane, and is typically thicker at the lower location than the central plane than the corresponding location above the central plane. Thus, the profile tends to twist during bending and generally employs a special process to prevent twisting during bending or a modification to remove twist after bending. Either one of the steps is required.
[0003]
Prior art bending devices are disclosed in U.S. Pat. No. 3,333,445 and Japanese JP-A-61-199517 (Japanese Patent Laid-Open No. 61-199517) and JP-A-61-199518 (Japanese Patent Laid-Open No. 61-199518). It is disclosed. These devices are devices that bend generally contrasting workpieces, already taking into account bending or springback during bending. Yo Ru equipment in the prior art for moving and controlling the workpiece is disclosed in Japanese Laid JP-A-5-131330 (JP-A-05-131330).
[0004]
The object of the present invention is that the bending, measuring and adjusting bending stages of the equator profile material, i.e. the adjusting bending stage taking into account both repulsion and springback as well as torsion, are particularly suitable for a single machine station. The object is to provide a bending apparatus which can be carried out in an efficient manner and is therefore preferably such that all machining steps are carried out in one process. Another object of the present invention is to easily and accurately move a workpiece in a bending press. Based on actual experience, there is often a productivity increase of more than twice when using the apparatus of the present invention. In addition, a correctly measured workpiece is obtained, thus making the assembly of the spherical tank easier. Since a separate measurement station is not required, space can be saved.
[0005]
The object of the invention is achieved by a method as claimed in claim 1.
Since the springback of the equator profile material is incorporated by calculation in the control program of the device, the desired bending result is usually achieved in only two bending stages. If the machining program includes measuring the shape of the equator profile with a measuring transducer after each press movement, deviations from the desired shape are confirmed immediately after the bending press movement. The adjusting action takes place immediately. The bending of the profile material is performed using two bending tools: a female tool outside the bent part and a male tool inside the bent part. In this case, the twist of the asymmetric profile material is such that at least two power cylinders, one power cylinder operating near one end of the profile material to be bent, and the other one with the bending tool. By using these two power cylinders, which operate near the opposite ends of the profile material, for forced coalescence, they can be controlled during bending. Automatic computer calculations are performed to control the press and corrective actions required.
[0006]
It is advantageous to use a so-called FEM program, ie a finite element method program or a similar method, in the computer calculation, by which the calculation work, the shape measurement work, and the additional work as well known in the art. Corrective work is performed accurately and quickly. The program also takes into account the properties of the workpiece as well as the asymmetric profile of the profile, so that the correct bending process is easily performed. This bending process is a reliable method, and actually functions automatically.
[0007]
The workpiece is large and heavy, but nevertheless it must be moved accurately at the machine station. In the press machine, the workpiece is moved by a driven transfer roller arranged near the claw of the press machine. Therefore, only one worker is required for bending and measuring operations. It is important that the radius of curvature is accurate. This is accomplished by moving the work piece from one bending position to another bending position by a short distance of 5-30 cm, preferably about 10 cm. The moving distance of the workpiece is measured by a measuring wheel arranged close to the bending point. The wheels are connected to a computer controller for the transfer roller. This device performs an accurate and quick movement almost completely automatically.
[0008]
The workpiece can be supported by an air cushion device that reduces frictional forces to a minimum. If the press has a suitable tool to correct overbending, the correction operation can be carried out quickly at the same machine station as the bending process. The tool for extending the excess bending is the same as the tool for bending the workpiece, but the installation position is reversed with respect to the bending plane of the workpiece and the asymmetry of the profile material with respect to the tool shape is reduced. It differs in that it needs to be taken into account.
[0009]
The present invention also relates to a bending process, and bent a profile material profile member, the bending is performed by a method or apparatus according to the present invention.
[0010]
The present invention will be described in detail with reference to the accompanying drawings.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In the figure, reference numeral 1 denotes a measuring / bending station having a bending press machine 2 capable of applying a pressing force exceeding 5000 KN. There are a measuring device 3 for controlling the bending of the equator profile material 4 of the spherical tank, and a bending tool 5 adapted to the shape of the workpiece. The profile material has a uniform cross-section along its length, but is asymmetric with respect to a central horizontal plane (i.e., a horizontal plane equidistant from the top and bottom edges of the profile material). The press has a rigid main body 6 fixed to a stable foundation. The measuring device 3 has a measuring transducer for measuring a workpiece and supplying the measured value to a control device (not shown) comprising a computer, preferably two on both sides of the bending position. Exists. As shown in FIG. 2, there are two transducers 7 at each measurement location, one near the top edge of the profile material and the other near the bottom edge of the profile material.
[0012]
The equatorial profile member 4 is moved in the direction indicated by the arrows 8a, 8b. The measuring transducer 7 can be adjusted in the direction of the arrows 9a, 9b. In order to move the equator profile 4 in the press 2, motor-driven transfer roller pairs 10a, 11a and 10b, 11b are used. These rollers automatically receive a control command from a control unit of a measurement system (not shown) or by manual control. If there are transfer rollers on both sides of the press, a fixing function is obtained. The rollers 11a and 11b are pressing rollers that stably press the workpiece 4 against the transfer rollers 10a and 10b.
[0013]
There is a measuring wheel 12 for measuring the amount of movement of the equatorial profile material 4 in the longitudinal direction. On both sides of the press, there are workpiece supports 13a, 13b supported by an air cushion foundation. They are lateral support elements 14a,
14b. The supports 13a and 13b can easily move on the floor, follow the workpiece, and support the weight thereof.
[0014]
The measuring transducer 7 is designed to be movable in the vertical direction in order to measure the equator profile material 4 at various heights. Also, a large number of transducers 7 may be provided so that they do not need to be moved vertically.
[0015]
The pressing machine has a tool 5a indicated by a solid line for bending a workpiece. The tool 5a is composed of a female tool outside the bending portion of the workpiece and a male tool inside the bending portion. The tool 5a is attached to the outer and inner tool supports 5.
[0016]
At the start of the bending process, one end of the equator profile material 4 is positioned at the first bending position in the press machine 2, and the other end of the equator profile material is the two supports 13a, 13b. The measurement system including the transducer 7 is adjusted for the task of monitoring the bending and springback of the workpiece. If the curvature has to be corrected, the transducer 7 provides the data necessary for continuous bending and straightening operations until the correct result is obtained by continuous measurement. The equator profile 4 is then moved to the next bending position, which is typically about 10 cm away from the previous position. The operation described above is repeated over the entire length of the equator profile material 4. During this operation, the supports 13a, 13b supported by the air cushion must be adjusted from time to time, or the number thereof must be increased or decreased. They are also adjusted to automatically follow the workpiece.
[0017]
FIG. 2 shows two cylinders 15 'and 15 "arranged to drive an inner tool support that supports a male bending tool 5a. The cylinders are spaced apart vertically. The cylinder 15 ′ acts on the male bending tool 5 a near the upper edge 4 ′ of the asymmetric profile member 4, while the cylinder 15 ″ acts on the male edge near the lower edge 4 ″ of the asymmetric profile member 4. Acting on the mold bending tool 5a The tool support 5, and thus the bending tool 5a, can swing around a horizontal axis perpendicular to the axis of the cylinders 15 ', 15 ". Because of this arrangement, it is possible to apply more pressure to one edge of the profile material than to the other edge to prevent the profile material from twisting during bending. By performing measurements with the transducer 7 during the bending process, the controller supplies a control signal to the male bending tool cylinder to correct the bending result and to prevent or correct profile twisting. be able to.
[0018]
Since the two transducers 7 at each measurement position are vertically separated, the controller can determine from the measurements provided by the transducers whether the profile has been twisted during bending. it can. When the bending tool 5a is activated to prevent twisting, the measured value can be used to confirm that the profile is not twisted to an unacceptable extent during bending.
[0019]
In the first stage, it is advantageous to perform rough bending rather close to the final shape, and then to perform final bending in the second stage. Accordingly, particularly good bending results can be obtained. By selecting the bending positions close to each other, the equator profile will be bent particularly accurately.
[0020]
The press machine may have a tool 5b indicated by a broken line for returning the excessive bending to the straightening direction. The male and female tools 5b are similar to the male and female tools 5a for bending the workpiece, but differ in that their relative positions are reversed with respect to the bending plane of the workpiece. Accordingly, the female tool 5a for bending the workpiece is disposed outside the bending portion, the male tool 5a is disposed inside the bending portion, and the female tool 5b for extending excessive bending is disposed inside the bending portion. The male tool 5b is disposed outside the bent portion. Naturally, the shape of the surface of each tool matches the side of the profile material with which the tool engages.
[0021]
The invention is not limited to the embodiments described above, but several modifications can be made within the scope of the appended claims.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a bending apparatus according to the present invention.
FIG. 2 is a side view of a principal part of the bending apparatus shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bending station 2 Bending press 3 Measuring apparatus 4 Equatorial profile material 5 Bending tool 7 Transducer 10a, 10b Roller 11a, 11b Roller 12 Measuring wheel 13a, 13b Workpiece support 14a, 14b Support element

Claims (17)

In a bending apparatus for bending an aluminum profile material (4, 4 ', 4 ") having an asymmetric cross section and having upper and lower edges with a press machine (2),
Means (10a, 11a, 10b, 11b) for moving the profile material through the press;
Bending tool for bending a profile material (4, 4 ', 4 ") by independent bending operations at a plurality of bending points spaced along the length of the pressing machine (5, 5a, 5b), at least one first power cylinder (15 ') positioned to act on the bending tool near the upper edge (4') of the profile material, and a lower edge ( A press machine having a second power cylinder (15 ") positioned to act on the bending tool near 4");
A measuring device (7) for measuring the shape of the profile material;
In combination with the press machine, based on the measurement result of the measuring device (7), both the bending of the profile material and the determination of the bending control are taken into account both the spring back and the twist of the profile material. And a control device for supplying control signals to the first and second power cylinders (15 ', 15 ").   The control device is arranged in the press machine to control the bending process and the bending correction, and the measuring device (7) is used to measure and inspect the shape of the bent profile material. The bending apparatus according to claim 1, wherein the bending apparatus is performed in a press after each bending operation.   The measuring device (7) includes a measuring transducer for measuring the shape of the profile material (4, 4 ', 4 ") in the vicinity of the bending point in each bending operation, and the measuring transducer is connected to the control device, The controller compares the actual bend with the desired bend result, controls the press to perform any additional bending or rebending required, and takes into account the profile material springback and torsion Item 3. A bending apparatus according to item 2.   The measuring device (7) comprises at least first and second transducers (7) for measuring the workpiece (4, 4 ', 4 ") at positions spaced apart in the vertical direction. The bending apparatus according to any one of claims 1 to 3.   The bending apparatus according to any one of claims 1 to 4, wherein the calculation for considering the springback and torsion of the profile material is performed by a finite element method.   Bending according to any one of claims 1 to 5, wherein the means for moving comprises rollers (10a, 11a, 10b, 11b) in the vicinity of the bending tool (5, 5a, 5b). apparatus.   Bending according to any one of the preceding claims, comprising measuring wheels (12) in contact with the profile material and measuring the movement of the profile material from one bending point to another bending point. apparatus.   The bending device according to any one of claims 1 to 7, further comprising an air cushion support device (13) for movably supporting the profile material.   The bending machine according to any one of claims 1 to 8, wherein the press machine has a device for correcting excessive bending. An aluminum profile member (4, 4 ', 4 ") having an asymmetric cross section by a pressing machine is bent by a bending apparatus according to any one of claims 1 to 9 into a desired final shape. There,
The profile material is moved along the length of the profile material during each stage of movement stoppage during each or each pass, in a step-wise manner, through the press in at least one pass. Performing another bending operation on the profile material (4) at spaced bend points.
In each bending operation, a bending force is applied to the profile material to bend the profile material (4, 4 ', 4 ") from the initial position through the intermediate position to the final position, followed by the force applied to the profile material. In the method of bending the profile material (4, 4 ', 4 ") to a desired final shape, wherein the profile material is spring-backed from the final position to the intermediate position by the elasticity of the profile material.
The bending force is non-uniform in the direction perpendicular to the length of the profile material (4, 4 ', 4 ") to correct and prevent the tendency of the profile material to twist during the bending operation; Controlled by controlling the first and second power cylinders. For each bending operation, the steps of applying a force to bend the profile material, releasing the applied force, and measuring the shape of the profile material are repeated one or more times, so the profile material The method according to claim 10, wherein bending and measuring are performed in two or more stages.   The method according to any one of claims 10 and 11, wherein in each bending operation, the bending operation of the profile material from the initial position to the intermediate position is automatically controlled by the control device. In each bending operation, the bending operation of the profile material from the initial position to the intermediate position is automatically controlled by the control device, and the bending operation includes a desired final profile material shape, a springback characteristic of the profile material, and a twist. 12. A method as claimed in claim 11 controlled by computer control means programmed to take into account the properties and the shape of the measured profile material .   13. A method according to any one of claims 10 to 12, wherein the movement of the profile material through the press to different bending positions is also automatically controlled by the control device.   15. A method according to any one of claims 10 to 14, wherein the profile material is supported by air cushion means movable on both sides of the press.   The method according to any one of claims 10 to 15, wherein the plurality of bending points are separated by an interval of 5 to 30 cm.   The method according to claim 16, wherein the plurality of bending points are separated by an interval of 10 to 20 cm.

Images