WO2000012239A1 - Device for bending frame sections - Google Patents

Abstract

Device for bending HP profiles in consecutive steps into a ship's frame section, comprising means for supporting the profile, means for the forwarding of the profile through the machine from a supply side to a discharge side of the device, first and second interspaced means for rotatably clamping or holding the profile and bending means situated between the first and second clamping or holding means, which bending means comprise an upper middle clamping or holding member and a lower middle clamping or holding member to move the profile in relation to the first and second clamping or holding means in a direction transverse to the forwarding direction when bending at a bending location, the device furthermore being provided with means for determining the bending location in transverse direction and in longitudinal direction of the profile, means for determining the included angle between the leading end and the trailing end of the profile, as well as operating means for the forwarding means, the clamping or holding means, the bending means and the angle determination means, and control means for the operating means, which control means control the operating means for the bending means also in response to a previous measurement by the angle determination means.

Description

Device for bending frame sections.

The invention relates to bending frame sections, in particular into the shape of HP profiles.

It is known to bend frame sections from straight HP profiles with the help of a bending machine. In one known method first a jig is made which shows the wanted curved course of a frame section, and said jig is placed contra to the profile which is still straight. Then the course of the jig's edge is copied with chalk on the profile that is still straight. The profile is then manually fed into the bending machine, which bending machine contains two side clamps which can rotate freely and each comprise an upper clamp and a lower clamp or two simple bending blocks, and placed in between them a bending yoke which can be moved transverse to the feeding direction, which bending yoke contains an upper clamping member and a lower clamping member. With great expertise the operator of the machine has the bending yoke engage the bead edge at the outside on a series of locations which are spaced apart in longitudinal direction so as to bend the profile concavely at said locations, in which the profile at the location of the side clamps/blocks can rotate freely, but for the rest is kept in its place. Usually one pair of frame sections at a time is bent, which are placed onto each other with the bead edges facing away from each other.

In this way a starboard frame section and a port frame section of a certain section can simultaneously be bent.

During the bending process it is regularly assessed on the basis of the course of the chalk line whether the bending process goes according to plan. Because the chalk line shows a counter curve the correct final result should show a straight chalk line. If such is not the case then a correction is necessary. As a result, after check on a total shape on actual size of the entire frame section (which requires additional time and additional aids), the profile has or profiles have to be fed anew into the bending machine for further correction.

Working with the known bending machine requires great skill, which is not always available. As a result the time integrally involved in making a bent frame section profile which deviates to an allowable extent from the wanted course, takes up more time than is acceptable from an efficiency point of view. It should be considered here that the profiles to be bent have to have an accuracy shape-wise of 1 mm per metre of profile length, an accurate total shape also being of importance.

From the Dutch patent application 79.01 784 it is known to determine in a bending machine the buckling angle realised with each bending step after said step with the help of the bending head itself. After arranging a buckle the bending head is moved back a little, after which it is moved again into the direction of the frame section, until the frame section is touched again.

The position of the bending head is then fixed and compared to the position of the bending head against the frame section determined earlier prior to the bending, so that it can be determined which buckle angle resulted from the bending action. A shortcoming of this measuring principle is that a systematic measuring error cannot be compensated in a next bending action.

For these reasons amongst others, there is a need for an automatic bending device, which can provide a sufficiently reproducible bending.

From one aspect the invention therefore provides a device for bending HP profiles in consecutive steps into a ship's frame section, comprising means for supporting the profile, means for the forwarding of the profile through the machine from a supply side to a discharge side of the device, first and second interspaced means for rotatably clamping or holding the profile and bending means situated between the first and second clamping or holding means, which bending means comprise an upper middle clamping or holding member and a lower middle clamping or holding member to move the profile in relation to the first and second clamping or holding means in a direction transverse to the forwarding direction when bending at a bending location, the device furthermore being provided with means for determining the bending location in transverse direction and in longitudinal direction of the profile, means for determining the included angle between the leading end and the trailing end of the profile, as well as operating means for the forwarding means, the clamping or holding means, the bending means and the angle determination means, and control means for the operating means, which control means control the operating means for the bending means also in response to a previous measurement by the angle determination means.

In the device according to the invention, the entire buckle angle of the frame section can be measured after each bending step. The measured buckle angle can be reckoned with in the next bending step. The systematic measuring error can then also be compensated in a next bending step, as a result of which less (high) requirements have to be made to the accuracy of the angle measurement.

With the device according to the invention the frame sections are bent into the correct shape in a numerical manner. On each precalculated position the buckle angle calculated for it is arranged. The buckle angle is built up from the theoretically necessary buckle, excluding elasticity, an addition in connection with theoretical elasticity, an addition in connection with the permanent plastic deformation locally at the bearing planes, as well as a calculated correction for correcting a bending error found in accordance with the invention after the previous bending step.

According to the invention the correction is determined by means of a measurement separate from the process of forces, as a result of which said measurement can take place irrespective of the elastic deformation of the machine and is independent of the possibly mechanical wear and tear or permanent plastic deformation of the machine in the long run.

The position of the bending location in longitudinal direction can be determined in a simple manner with the help of a measurement roll which can be pressed against the profile and of which the number of revolutions is a standard for the location along the profile. Here means are provided for sensing the head front edge of the profile at the supply side. With the help of the known distances between measurement roll and bending means and measurement roll and front edge the exact, momentary location of the bending location can be determined.

The angle determination means preferably comprise means for determining the orientation of an edge of the profile at the end concerned with regard to a reference line.

The angle determination means at the supply side near the trailing end are preferably mechanically active. Because the bent part of the profile at the supply side of the device is straight in principle, the angle determination means situated there can be situated as close as possible near the bending means, just outside the clamping means situated at the supply side, because the necessary transverse movement of the measurement system is almost nil. As a result the mechanical structure of the angle determination means can remain simple. An additional advantage of said location is that a possibly present curve in the straight profile can largely be taken into account in the bending.

The angle determination means at the supply side preferably comprise two vertical rolls, of which one is moveable in transverse direction until in abutment with the profile edge and has an axis of rotation and the other is able to swivel about said axis of rotation until in abutment with the profile edge, the axis of rotation being coupled to an angle encoder. Thus the control means are informed of the angle position of the axis of rotation in relation to a reference line. When both rolls are placed well against the profile, the angle of the profile there is thus determined. One or both of these rolls can be adapted as measurement roll for determining the location in the longitudinal direction.

The angle determination means at the leading end have to be able to move along with the profile at that location as the bending progresses. Of nearly all occurring frame sections to be bent the profile end moves in a rectangle of approximately 10 to 7 metres. Said angle determination means therefore have to be able to be moved over a large area. According to a further development of the invention this is made possible by means of angle determination means which are active -without contact and- at a distance, preferably with the help of a laser. Said laser can be arranged on a portal which moves over the area where the portion of the profile discharged from the bending machine is supported. The laser can be moved by the control means to the expected, calculated location of the end of the profile.

Subsequently the actual position of the end of the profile is scanned with the help of the laser. After that the course of the edge is scanned at at least two locations, so that also the angle at the end is known. The deviation in the actual position of the end is iteratively included in the prediction of the actual position after each next bending action. From another aspect the invention provides a device for bending the frame section profiles with an improved control of the possible clamping forces exerted by the first and second middle clamp or holding means. These forces are of influence on the size of the profiles to be processed. Par- ticularly the middle clamping or holding system plays an importance part here. Two holding or clamping members in the middle of the bending device hold the profile onto the clamp where it is plastically deformed. When the exerted clamping forces are to large deformation of the profile does not take place in a regular manner anymore. In known bending machines use is made of a central pump in the hydraulic system for all partial processes. This means that the pump which ensures the bending also ensures correctly pressurizing the clamps. Because of the various operating pressures of the clamps and the cylinders for the bending means they cannot be operated simultaneously, so that the clamps have to be pressurized prior to each bending action.

According to the invention it is now provided to accommodate middle and side clamps or holders in an operating system, particularly the hydraulic system, controlled by the control means. In this way the mutual distance during bending can be kept constant.

Here preferably the invention provides a device for bending frame section profiles in which at least one of the frame section clamps or holders of at least one of the pairs of frame section clamps or holders is operated by means of a hydraulic piston/cylinder assembly, in which at the side of the piston a chamber is formed which can be pressurized by means of a hydraulic pressure source for moving the clamp or holder toward the frame section, furthermore comprising means operable by the pressure source for closing the chamber when it is at the desired pressure.

Preferably the closing means comprising a seat valve, which on the one hand at the annular side can be connected to the pressure source via a first valve, being in connection with the chamber at the narrow piston side and which can selectively be connected to a pressureless line or the chamber at the bottom or wide piston side via a second valve.

Preferably this device comprises a switching valve, which on the one hand is connected to the bottom or the wide piston side of the seat valve via the second valve, and on the other hand is connected to the annular side as well as the narrow piston side of the seat valve, so that the highest pressure of the narrow or annular side is passed on to the bottom side.

Preferably the rod side of the cylinder can be put into connection with the pressure source via the first valve.

According to another aspect the invention provides a device for bending frame section profiles in which the holding or clamping means in the centre and at the supply and discharge side are operated by means of a hydraulic system which can be controlled separately with regard to the control system for the transverse movement of the bending means.

From a next aspect the invention provides a device for bending frame section profiles with side and middle clamping or holding members, in which the middle clamping or holding members have convex surfaces in longitudinal direction. In this manner it is ensured that at the location of the largest plastic deformation the restraining of the profile is maximal, whereas where only guiding and no clamping is necessary the frictional forces during the bending process are minimized.

From yet another aspect the invention provides a device for bending frame section profiles, provided with side clamping or holding members and middle clamping or holding members, in which the middle clamping or holding member comprises a lower middle clamping or holding member and an upper middle clamping or holding member, which lower middle clamping or holding member extends beyond the upper middle clamping or holding member. In this way it is not necessary to bend the starboard and port frame sections simultaneously. The projecting part of the lower middle clamping member prevents a downward tilting to the outside of the bead, as a result of which during bending no large forces occur in the neck of the bead and plastic deformation is avoided there.

Preferably at least one of the first and second clamping or holding means comprises an upper clamping or holding member, which is provided with a receiving space for the bead and both with a stop surface for the inside of the bead and a stop surface for the outside of the bead.

Nowadays the profiles are coated with zinc silicate-based shop primers. It appeared that the friction between clamping means and the profile increases after performing a number of bending actions, as a result of pollution occurring in practice. With unpolluted clamping surfaces the friction level initially remained good, until a certain pollution level is ex- ceeded. As a result the friction increased very quickly to unacceptable levels. It appeared that a first pollution of the clamps promotes further pollution.

From another aspect the invention provides a solution for this, by applying a lubricant on the profile prior to clamping. The lubricant preferably contains components which do not become active until with very high surface pressures and preferably contains solvents as a result of which the clamping surface is kept clean. Such lubricants are used in heavy surface and frictional loads. Preferably the lubricant is applied very locally. It appeared that applying lubricant only in the neck of the bead at the location of a bending location can be sufficient. From an efficiency point of view usually profiles of a standard length, for instance 12 metres, are used, from which possibly several frame sections can be obtained. In that case the device according to the invention can be provided with a cutting device with which a bent frame section can roughly be separated form the trailing, still substantially unbent, part of the profile.

A bent frame section subsequently has to be made ready for delivery to the client. Part of this is the final check of the bending result, the application of reference lines for the assembly of the parts to a ship's section in the shape of water lines and end lines on the frame sections, the coding, that is to say the numbering of the frame sections, placing letters and numerals at the water lines and other marking points on the frame section, and applying notches and/or water discharge holes in some of the frame sections.

For at least a part of this finishing process the invention provides a device for assessing the course of a profile which has been brought in an at least substantially wanted arched shape, comprising means for supporting the profile, scanning means for sensing a point on the weld side or jig side of the profile, operating means for the scanning means, and control means for the operating means, which control means are adapted to have the operating means have the scanning means follow a track along the weld side after sensing the weld side or jig side, until at the head edge of the profile, and to subsequently have the scanning means follow the weld side of said head edge according to a scanning track to the other end side in order to determine its course, in which the device is furthermore provided with means for storing the course of an edge wanted for a certain profile, and with means for storing the course of the edge as sensed by the determining means, as well as means for comparing the wanted and the actual course of the edge and means for showing the results of said comparison.

Here no use has to be made of a pre-arranged point of reference on the profile. Instead a complete scan of the profile shape is made, after which numerical two-dimensional matching of the measured and the numerical reference shape is made. The algorithm works according to the best-fit method, as a result of which a minimisation of the shape deviation can be achieved.

On the basis of said comparison the profile concerned can be approved of or rejected. Rejection can take place when the maximum shape deviation over the entire length of the bent profile is 1 mm per m' with a comparable requirement of the dimensional shape and the maximal local shape deviation over each part of the profile of 1 metre is more than 1 mm.

In an advantageous manner the data regarding the actual shape of the profile, as it sits there, can be used for one or more of the above-mentioned other steps in the finishing process. To that end the device comprises means for applying marks on the profile, which are controlled by the control means in response to the data of the scanning means. The marking means can be arranged on a portal, on which also the scanning means, preferably laser means, have been arranged. They can be arranged on the same trolley or on several trolleys.

The marking means preferably comprise an ink jet. With said ink jet a bar code can also be applied, possibly after locally a white background has been applied. As a result with the same means (the ink jet) several forms of information are applied. The use of separate stickers with bar codes, which have to be removed at the wharf, can then be omitted.

The device can also be provided with a cutting device which can also be arranged on the same trolley as the scanning means and/or the marking means. With the cutting device the exact final shapes and possible recesses are arranged in the profile.

The cutting device could also possibly be used for heating the aforementioned lubricant, in order to have it evaporate completely. The adhesion process of the coat of paint later to be applied on the frame sections can then not be detrimentally influenced by the lubricant.

The invention will now be elucidated on the basis of an exemplary arrangement shown in the attached drawings.

Figure 1 shows a schematic top view on a exemplary arrangement of the devices according to the invention, with indicated processing direction;

Figure 2 shows a schematic top view on the frame section bending machine in the arrangement of figure 1 ;

Figures 3A and 3B respectively, show a front view and a top view on the frame section bending machine of figure 2;

Figures 4A and 4B show a schematic front view and a top view on the clamping members of the frame section bending machine of figure 2;

Figure 4C and 4D show cross-sections according to IVC-IVC and IVD-IVD in figure 4A;

Figure 5 shows a part of a hydraulic diagram of the operation of the upper middle clamp;

Figures 6A-6C, respectively, are a top view, front view and a side view of the check and marking device in the arrangement of figure 1 ;

Figure 7 shows a view on a part of the check and marking device of the figures 6A-6C;

Figures 8A-8C, respectively, show a top view, a side view and a front view on a burner device accommodated in the check and marking device of the figures 6A-6C;

Figure 9 shows a frame section during and after the treatment in the check and marking device;

Figure 10 shows a flow chart of the bending process with the frame section bending device according to figure 2; and

Figure 1 1 shows a flow chart of the check and marking process with the check and marking device of the figures 6A-6C.

In figure 1 an arrangement 1 is shown, in which the straight profiles 2a are supplied from the direction A to an intermediate storage 3. From the intermediate storage 3 the profiles 2a are supplied in the direction B via an automatic transverse conveyance buffer 4a which offers the profiles single to a supply roller track 4b, from which the profiles are conveyed in the direction C through a DNC frame section bending machine 5 to a discharge roller track 6. From the discharge roller track 6 the bent frame sections 2b are moved to an intermediate storage 7, and subsequently in the direction E to a marking device 8, where they are checked as to shape, provided with marks and cut to size. After that the bent frame section goes in the direction F to a burring station 9a and from there in direction G to a sorting location 9b in order to be sent package-shaped with other profiles and possibly plates from there to the client in the direction H. As shown in figure 2 the supply roller track 4 comprises a number of freely rotatable rolls 10. With means that are not shown the frame sections 2a can be conveyed transverse to the rolls 1 0 and with driven rolls 10' each time one profile can be conveyed into the bending device 5.

Also the discharge roller track 6 is provided with a number of rolls 10, but furthermore with a combined end angle measurement and cutting device 30, which comprises a portal 32, which is reciprocally moveable in the directions I over rails 31 and on which a trolley 33 is reciprocally moveable in the directions J. On the trolley 33 a laser scanner 34 and a cutting torch

35 are arranged. For the operation of all these parts and the adjustment one to the other of their activities a control unit 1 1 with operation panels 1 1 a and 1 1 b and a hydraulic unit 1 2 controlled by it is provided.

As can be seen in the figures 3A and 3B the frame section bending machine 5 comprises a first pair of side clamps or holders with an upper side clamp or holder 1 3a and a lower side clamp or holder 1 3b, a second pair of side clamps or holders with upper side clamp or holder 14a and lower side clamp or holder 14b, and a pair of middle clamps or holders with upper middle clamp or holder 1 5a and lower middle clamp or holder

1 5b, which are all arranged on a chassis 22. With schematically shown hydraulic means 23, 24, 25a and 25b the upper side clamp 1 3a, the upper side clamp 14a, the upper middle clamp 25a and the lower middle clamp 25b, respectively, can be moved up and down in a controlled manner.

At the supply side the frame section bending machine 5 is furthermore provided with profile forwarding means, comprising a frame 1 9 situated at the bottom, which frame can be moved up and down with the help of cylinder 20 and is provided with a in a not further indicated manner (propo- rtionally), controlled driven conveyance roll 1 6 and a support roll 27 are arranged, and a frame 1 7 situated at the top, which can be moved up and down by means of cylinder 18 and is provided with a pressure roll 21 . These parts are arranged on an auxiliary frame 26 which attached to the chassis 22 in a manner rotatable about the centre line X. The frame 26 is swivelled by means of a drive, which is not further shown, which is controlled by the control unit.

Downstream of the conveyance roll 1 6 there is a detector 100 for roughly detecting the location of the profile in connection with activating the conveyance roll 1 6. At the discharge side of the bending device 5 a pair of rolls 106 is situated, which, with the rolls 107 and 1 08 that are adjustable as to height and are partially driven, can clamp and forward the profile when it has passed entirely by the conveyance roll 1 6. Directly upstream from it a detector 109 is situated for fine detection of the head edge of the profile and activating the pair of rolls 106.

Behind the frame 26 an angle and length gauger 1 1 0 is situated, which comprises a running or measurement roll 1 01 provided with an encoder and an abutment roll 102, in which the rolls 101 and 1 02 are connected to each other by a rod 103, which can be swivelled about a vertical axis in the directions K. Means that are not shown are present for measuring the angle between the rod 103 and a reference axis L which is parallel to the direction I (figure 2) and to the forwarding direction in the bending machine 5.

At the upstream side of the frame 26 the bending machine 5 is furthermore provided with a transverse series of nozzles 104, which each via supply lines 1 05 are in connection to the lubricant source to be pressurized.

As shown in figure 4A the clamping surfaces of the upper middle clamp 1 5a and the lower middle clamp 1 5b are substantially convex , as seen in longitudinal direction. Thus the surface of the upper middle clamp 1 5a has a bent central surface 94a and situated on both sides thereof also bent surfaces 95a. The surface of the lower middle clamp also has a central flat surface 94b and on both its sides bent surfaces 95b.

In a diagram it is shown that the side clamps 1 3a, 1 3b, 14a, 14b are freely rotatable on a vertical axis.

In figure 4B it can be seen that the upright surfaces 96 and 97, which face the profile, of the upper means 1 5a and the pressure block 28, respec- tively, are convex.

Furthermore it can be seen in the figures 4B and 4D that the upper side clamps 1 3a and 14a are parted, at least define a receiving space 1 3c for the bead edge of the profile 2 and have a stop surface 120 for convex bending (when pressure block 28 is used and plate 1 5a is only used for keeping the profile flat) and a stop surface 1 21 for concave bending (when plates 1 5a, b are used).

In figure 4C it can be seen that the lower middle clamp 1 5b extends below beyond the upper middle clamp 1 5a. In this way the bead 90 of the profile

2 is supported, which is of importance in concave bending in which the surface 96 presses against the bead and in which the bead is situated in a tensile region. The plates 1 5a, b in this case furthermore prevent wrinkle formation in the pressure zones.

At the machine side there is a pressure block 28, which just like the middle clamps 1 5a, 1 5b can be moved in the transverse directions Y and thus is coupled for movement in transverse direction, and is used when the profile 2 with the bead 90 has to bent concavely. The plate 1 5a is then held just over the profile to prevent warping. It is noted here that the bending machine 5 should be used for bending concave frame sections, convex frame sections and the combined S frame sections.

Also shown are furthermore three spray nozzles 104 for spraying lubricant in the neck of the profile 2b.

In figure 5 it is schematically shown in which way a clamp or holder, here the upper middle clamp or holder 200, is pressurized and can be kept at pressure. It has to be understood that in the drawing the direction toward the frame section is seen upwardly. In reality this is the other way around.

The clamp or holder 200 sits on a piston rod 202, at the end of which a piston 203 is placed, which closes off the pressure chamber 204. Via a pressure line 21 2, 205 and valve 206 and pressure line 209 the chamber 204 can be brought in connection with the pressure source 210. The valve 206 can either be slid to the left or to the right by activating the coils 207,

208. The other side, the rod side, of the piston 203 can also be brought in connection with the pressure source 210 via the line 21 1 and the valve 206.

Special is that the line 205 debouches in the annular chamber of a seat valve 21 3. Via the line 21 2 the chamber 204 is connected to the upper end of the seat valve 213 opposite the narrow piston side 217. The broad piston side 21 5 of the seat valve 21 3 can be connected via line 224 to a pressureless line, for instance leak-off oil line, via valve 221 which is operable by means of coil 222, or can be connected via line 220 to a switching valve 21 9, which via line 21 6 is connected to the aforementioned annular chamber of the seat valve 21 3 and via line 21 8 can be connected to line 21 2.

When the clamp or holder 200 has to be moved to the frame section, coil

207 is activated, so that the pressure source 210 is in connection with the line 205 and with the line 21 1 . Because of the pressure on the line 205 the piston 214 in the seat valve 21 3 is urged downward. The piston 21 4 can move downward because the space underneath it is in connection with the pressureless line via the valve 221 . The pressure in the line 205 can be passed on via the line 21 2 to the chamber 204. In this way the piston 203 is put under the wanted pressure. Because of the difference in the sizes of the surface between the rod side of the piston 203 and its side facing the chamber 204 the piston rod 202 will be expanded.

Subsequently the coil 222, is operated, so that the valve 221 ensures that the pressure in line 205, via the annular chamber of the seat part 1 1 3, and via the switching valve 21 9, is passed on to the bottom chamber of the seat valve 21 3. The surface on the bottom side of the seat part is larger than the annular surface and the head surface of the seat valve, so that the seat valve closes again.

By exciting the coil 208 the valve 206 is moved to the right again, in order to thus depressurize line 205 and only pressurize the line 21 1 .

With these measures it is achieved that the piston 203 and the holder or clamp connected thereto can be kept in an exact, fixed position in relation to the frame section.

In the figures 6A-6C the check and marking device 8 is shown. The check and marking device 8 comprises a framework 45, on which (schematically shown) a grid 46 is placed. The grid 46 serve to support a bent frame section to be checked and marked, and forms meshes which are large enough to let through the pieces of the frame section that are cut off.

On either side of the framework 45 two rails are situated, which for the sake of safety are screened by railings 49. The portal 42 can be moved over the rails 41 with the help of driving sets 43. On the portal 42 a trolley 44 provided with an own drive 81 can be reciprocally moved. On the trolley 44 a scanning and marking unit 47 and a cutting unit 48 are arranged. These units and the aforementioned drives are controlled by a central driving unit 50, which is provided with a operation display unit 51 .

The scanning and marking unit 47, shown in more detail in figure 7, comprises a carrier 63 which is attached to the trolley 44 and on which a servo motor 61 and a servo motor 62, as well as an ink reservoir 60 have been arranged. The servo motor 61 is provided with an exit shaft 61 a, which is in engagement with the block 64 in such a manner that the rotation of the exit shaft 61 a results in a vertical displacement of the block 64. Bearings 65 are attached on the block 64, which for vertical displacement are permanently connected to rod 66, which is connected to the keyed exit shaft 62a of the servo motor 62 for co-rotation. At the bottom side of the rod 66 there is a sensor 67, which can sense the position of the profile 2b.

On the rod 66 a block 73 is attached on which, in an indirect manner a rod 68 is attached, on which a print head 70 and a protective casing 71 for it are attached. The print head 70 is connected to the ink reservoir 60 by means of an ink line 69.

It will be understood that the sensor 67 and the print head 70 can be put at the right level with the help of the servo motor 61 . By means of the servo motor 62 the print head 71 can be rotated.

The cutting unit 47 shown in the figures 8A and 8B comprises a carrier plate fixedly attached to the trolley 44, on which plate also the carrier 63 is attached. On the carrier plate 80 there is a servo motor 81 , with which the driving wheels 82 are driven to reciprocally move the trolley 44 over the portal 42. On the carrier plate 80 a vertical support 87 is attached, at the upper end of which a transverse plate 88 is attached. On the transverse plate 88 a linear sensor 83 is attached, with which the height position of the rod 89 is determined. The rod 89 can be slid up and down within an adjustment unit 84 which is hinged to the support 87, where means are arranged which are driven by servo motor 97 for vertical displacement of the rod 89. At the lower end of the rod 89 a clamping piece 85 is attached, in which a cutting torch 86 is clamped. The scanning and marking unit 47 is only schematically shown here.

The operation of the frame section bending machine is as follows. Data regarding the length of a supplied profile 2 are fed into the control unit 1 1 , such as its length, the length of the frame sections to be got from said profile and the material characteristics, as well as the wanted bent shapes of the frame sections. On the basis of all this the computer in the control unit 1 1 calculates on which locations along the length of the profile a bending step has to be carried out and over what angle.

With the help of driven rolls 10' a profile 2 is conveyed to the frame section bending machine 5 until the profile has arrived at the level of the conveyance roll 1 6. Then the frame 1 9 is moved upward until the conveyance roll 1 9 has come into contact with the lower surface of the profile 2. Then also the frame 1 7 is moved downward to move the pressure roll 21 against the upper surface of the profile 2. With the help of suitable means the leading end of the profile 2 is determined and stored in the control unit 1 1 . On the basis of the calculated wanted first bending location, the control unit now gives a signal as a result of which the driving roll 1 6 conveys the profile 2 until at the pair of side clamps 14a, 14b. With the help of the roll 101 with encoder it is known exactly where the leading end is and the profile 2 can be placed exactly with the first wanted bending location in the heart of the pair of middle clamps 1 5a, 1 5b. ln the first bending step no bending correction has to be taken into account, because the profile is after all still straight.

During the conveyance of the profile it is sprayed with a lubricant with the help of spray nozzle 104 (figures 3A, 3B, 4C) on all locations where during the bending process high surface pressures are exerted. As a result too high a friction between the clamping surfaces and the ground layer of the zinc silicate-based coating of the profiles is avoided, so that the clamping surfaces remain clean and the friction coefficients during bending the entire profile remain substantially constant.

When the profile is brought at the correct place, the conveyance roll 1 6 is stopped and it is lowered. The pressure roll 1 7 is made pressureless, so that the profile is free to move in transverse direction, should this be necessary.

Then the side clamps 1 3a, 14a are lowered to the profile 2. The profile 2 here is already supported by the bottom side clamps 13b, 14b.

Subsequently the lower middle clamp is raised until at the level of the lower side clamps 1 3b, 14b. Then the upper middle clamp 1 5a is brought to the fore and down towards the profile 2 step-wise. Subsequently the control unit 1 1 operates the pair of middle clamps 1 5a, 1 5b in transverse direction in the direction of the bending (concave or convex), away from the bead, to have the bead abut the inner edge of the upper side clamps

1 3a, 14a. Said abutment is detected on the basis of the pressure build-up in the hydraulic system for operating the middle clamp in transverse direction. The side clamps then rotate along passively.

The hydraulic unit 1 2 with the accompanying control system can be built up such, that the excitation of the clamps in vertical direction is realised by means of a system which is separated from the system with which the middle clamp is moved in transverse direction for performing the bending deformation.

As can be seen in figure 4C, during bending, the profile 2 is also supported at the location of the bead 90 in order to counteract torsion in the bead during concave bending.

The hydraulic system is activated by the control unit for the transverse displacement of the middle clamp in order to move it over a certain predetermined distance. The side clamps 1 3, 14 here keep the profile 2 in its place in transverse direction, but do allow a local rotation thereof, because the side clamps 1 3, 14 are arranged in a freely rotatable manner.

The profile is now buckled over a numerically pre-calculated value according to a three-point bending. In this bending value the next parameters stored in the control unit are included: - the theoretical necessary buckle exclusive elastic deformation; the addition in connection with the theoretical elastic deformation; the addition in connection with the plastic deformation of the profile, locally near the clamping surfaces; and the actual point zero to be determined during the bending on the basis of relative pressure measurement (in a dynamical manner, at the moment the effective bending is started with) .

After the middle clamp has been displaced over the calculated distance in transverse direction, the control unit 1 1 stops its movement and the upper middle clamp 1 5a and/or (depending on the direction of bending) the pressure plate 28 is moved until it/they are no longer in contact with the profile 2.

Subsequently the drive 25 is controlled by the control unit 1 1 to lift the upper middle clamp 1 5a to some level above the profile 2. The control unit 1 1 here also controls the drives 23 and 24 to lift the side clamps 1 3a, 14a to some level above the profile 2. The control unit 1 1 subsequently controls the drive 25b to bring the lower middle clamp 1 5b to a little distance below the profile 2.

The profile 2 is now completely free in the bending machine 5. The control unit 1 1 now activates the driving means of the scanning system on the discharge side, that is to say the portal 32 and the trolley 33. These are operated such that the laser scanning system 34 is moved to the theoretical position, after said bending step, of the end of the bent profile 2 as calculated in the control unit 1 1 .

After that said driving means are activated by the control unit 1 1 to scan the actual position of the end of the bent profile 2. The laser sensor 34 which is arranged on the trolley 33, is here brought to a point on the frame section and after that moved in longitudinal direction, until the head edge of the first frame section is reached. After that the control unit 1 1 operates the portal 32 and the trolley 33 such, that with a returning movement a point on the weld side and subsequently with a further returning movement a second point on the weld side are determined near the end of the profile. The laser measurement takes place on the basis of determining the different x, y positions of the weld side of the end of the bent profile 2. The positions are determined by a Z-measurement to be performed from a fixed level of the support surface of the profile. With the level measurement the edge is scanned on points. The two points mentioned give an exact measure of the angle the jig side and thus the profile 2 take up at that location.

Simultaneously with the help of the angle measurement rod 103, also the angle which the edge of the profile makes at that location is determined at the supply side, by arranging the two rolls 101 and 102 against the profile edge.

The control unit 1 1 now calculates the location of the data from the angle measurement at the discharge side and at the supply side the actual buckle which is present in the profile 2. The control unit 1 1 subsequently determines the difference with the angle which should have been realised in this bending step (calculate). On the basis of the material characteristics fed the control unit calculates the correction necessary in the next bending step in the profile in order to completely compensate the general shape error realised up until now.

Now the driving roll 1 6 is lifted again by the control unit 1 1 , until approximately 3 mm above the level of the fixed side clamps 1 3b, 14b. Also the pressure roll 1 7 is moved downward, until the profile is clamped between the conveyance roll 1 6 and the pressure roll 1 7. The control unit 1 1 subsequently has the conveyance roll 1 6 driven to bring the profile 2 to the correct position for the next bending step. The pressure plate 28 here is displaced such during the conveyance that always at least 5 mm free passage space for the profile 2 between the upper clamp 1 5a and the pressure plate 28 is kept. During the conveyance the above-mentioned locations are sprayed with lubricant again. The above-mentioned steps are subsequently performed again, in which however in bending the profile the calculated correction is taken into account by the control unit 1 1 .

When the profile is bent over the wanted frame section length, the profile 2 is conveyed so far through the frame section bending machine 5 with the help of the conveyance roll 1 6, that the cutting torch 35 on the trolley 33 can be brought at the level of the trailing end of said profile. The location of the end of the frame section is determined by the control unit 1 1 by means of length determination on the basis of the number of revolutions of the conveyance roll 1 6 and by means of the laser scanner 34. After the approximate position of the trailing end of the frame section has been determined by the control unit 1 1 , the cutting torch 35 is activated as a result of it, in order to cut the profile 2 at that location by means of a movement of the trolley 33 transverse to the centre line of the profile 2.

The frame section 2b thus bent, is subsequently directly or indirectly transferred to the shape check and marking unit 8.

With the shape check and marking device 8 it is assessed independently from the bending process and the frame section bending machine 4 whether the criteria as required in a production process according to the ISO 9002 are met.

The bent frame section 2b is laid on the grid 46 near the portal with suitable conveyance and hoisting means. It is not of importance which orientation the frame section 2b has there. Data regarding the wanted shape of the frame section concerned are fed into the control unit 50.

The frame section 2b will always lie with the bead 90 on top.

The control unit 50 now has the trolley 44 driven to have the sensor 67 run a straight line in the y direction at a distance of approximately 2 metres in the x direction. During carrying out said movement the level is measured and the body of the frame section 2b can be found. If that taken place the control unit 50 has the movement of sensor 67 prolonged over some distance. Here the top level can be determined, which is the bead 90.

Subsequently the sensor 67 is moved by the control unit 50, which takes place on the basis of the fed data regarding the width of the profile and after that the driving means for the portal 42 and the trolley 44 are driven to move the sensor along the weld side and/or jig side 91 , in which the trolley 44 is moved such in the x-y plane, that the sensor 67 follows a oscillatory movement S (see figure 9) . When no material is detected, the movement of the sensor is reversed again.

By reading out the sensor with a high frequency the point where the sensor 67 runs from the jig side can be accurately determined. This point is then in addition corrected for the speed of the sensor in the x direction and in the y direction. The sensor also has a certain offset, for which correction is also carried out. If in this manner a point of the weld side is determined, together with the previous point the direction of the frame section can be determined. With this information the edge follow movement to be made can be corrected so that the edge cannot get "lost" . In this case at regular distances along the frame section edge an edge point position is measured until the head edge of the profile is found.

When the beginning of the frame section 2b is found, the edge concerned is scanned again in the same manner, but now from said beginning to the other end. The point that is measured, is stored in the control unit 50.

After the entire frame section shape has been measured thus, the scanned points set is first translated and rotated such in the unit 50 that it can be fitted on the reference frame section shape as well as possible. After that the difference between both shapes is calculated. When the criteria (mentioned earlier) are met then the frame section is approved of. When one of the criteria is not met, the frame section is rejected.

When the frame section is approved of it can be further finished. The control unit 50 and the movement of the trolley 44 are used for this as well. The wanted marking spots have been fed into the control unit 50.

The control unit 50 knows the exact location of the frame section 26 and drives the driving means of the portal 42 and the trolley 44 to bring the print head or ink jet 70 at the correct position above the frame section 2b. By operating the servo motors 61 and 62 the ink jet 70 can apply lines 1 1 3 and letters and numerals and other signs. The application of these signs takes place in one stroke, a returning stroke, along the frame section 2b.

The device 8 can then be used again in a next, forward stroke, by moving the torch 86 at a heightened level above and along the frame section 2b in which on the basis of data regarding the bending locations fed into the control unit 50, the torch 86 is controlled to spread heat on those bending locations until a temperature of at least 280° is reached there. The punch oil is removed from the frame section 2b in that way.

When the trolley 44 has reached the end of the frame section 2b, it can be returned again by the control unit 50, in order to burn the frame section 2b at exactly the correct end length and where wanted burn in recesses with the help of the control of the torch 86.

Finally, with the help of ink jet 70 a bar code 1 1 2 can be applied on the frame section 26 on a white background 1 1 1 applied earlier, in which all information regarding the frame section can be included. The white background 1 1 1 can be formed by white ink and/or paint, which can be painted over.

After that the frame section 2b is ready to be assembled with several other frame sections into a building kit of a ship.

Claims

Claims

1 . Device for bending HP profiles in consecutive steps into a ship's frame section, comprising means for supporting the profile, means for the forwarding of the profile through the machine from a supply side to a discharge side of the device, first and second interspaced means for rotatably clamping or holding the profile and bending means situated between the first and second clamping or holding means, which bending means comprise an upper middle clamping or holding member and a lower middle clamping or holding member to move the profile in relation to the first and second clamping or holding means in a direction transverse to the forwar- ding direction when bending at a bending location, the device furthermore being provided with means for determining the bending location in transverse direction and in longitudinal direction of the profile, means for determining the included angle between the leading end and the trailing end of the profile, as well as operating means for the forwarding means, the clamping or holding means, the bending means and the angle determination means, and control means for the operating means, which control means control the operating means for the bending means also in response to a previous measurement by the angle determination means.

2. Device according to claim 1 , the angle determination means comprising means for determining the orientation of an edge of the profile at the end concerned in relation to a reference line.

3. Device according to claim 2, the angle determination means for the trailing end being mechanically active.

4. Device according to claim 3, the angle determination means for the trailing end comprising two vertical rolls, of which one can be moved in transverse direction against the profile edge and has an axis of rotation and the other being able to swivel about said axis of rotation until in abutment with the profile edge, the axis of rotation being coupled to an angle encoder.

5. Device according to claim 2, 3 or 4, the angle determination means for the leading end being active without contact and at a distance, preferably with the help of a laser.

6. Device according to any one of the preceding claims, in which the position of the bending location in longitudinal direction is determined with the help of a measurement roll which can be pressed against the profile and of which the number of revolutions is a standard for the location along the profile.

7. Device according to any one of the preceding claims, the control means being provided with means for storing the value of the wanted angles at both ends after each bending step, and with means for comparing the determined angles to the angles that are wanted after a certain bending step.

8. Device according to any one of the preceding claims, the middle clam- ping or holding members having convex surfaces in longitudinal direction with a flat intermediate part.

9. Device according to any one of the preceding claims, the lower middle clamping or holding member extending beyond the upper middle clamping member.

1 0. Device according to any one of the preceding claims, in which at least one of the first and second clamping or holding means comprises an upper clamping or holding member, which is provided with a receiving space for the bead and with both a stop surface for the inside of the bead and a stop surface for the outside of the bead.

1 1 . Device according to any one of the preceding claims, furthermore comprising means for applying a lubricant at the place of the body of the profile where the upper middle clamping member will engage, preferably in the neck of the bead of the profile.

1 2. Device according to any one of the preceding claims, the clamping or holding means in the centre and at the supply and discharge side being operated by means of an hydraulic system which can be controlled separately with regard to the control system for the transverse movement of the bending means.

1 3. Device according to any one of the preceding claims, at least one of the frame section clamps or holders of at least one of the pairs of frame section clamps or holders being operated by means of a hydraulic piston/cylinder assembly, in which at the side of the piston a chamber is formed which can be pressurized by means of a hydraulic pressure source for moving the clamp or holder toward the frame section, furthermore comprising means operable by the pressure source for closing the chamber when it is at the desired pressure.

14. Device according to claim 1 3, the closing means comprising a seat valve, which on the one hand at the ring side can be connected to the pressure source via a first valve, being in connection with the chamber at the narrow piston side and which can selectively be connected to a pressureless line or the chamber at the bottom or wide piston side via a second valve.

1 5. Device according to claim 1 4, furthermore comprising a switching valve, which on the one hand is connected to the bottom or the wide piston side of the seat valve via the second valve, and on the other hand is connected to the ring side as well as the narrow piston side of the seat valve, so that the highest pressure of the narrow or ring side is passed on to the bottom side.

1 6. Device according to claim 1 3, 14 or 1 5, in which the rod side of the cylinder can be put into connection with the pressure source via the first valve.

1 7. Device for determining the course of a profile, in particular a steel frame section profile, comprising means for supporting the profile, scanning means for sensing any one point on the body of the profile, operating means for the scanning means, and control means for the operating means, which control means are adapted to have the operating means have the scanning means sense the bead edge after sensing the profile and to have it follow a winding track along the weld edge, the device furthermore being provided with means for storing the course of an edge wanted for a certain profile, and of means for storing the course of the edge as sensed by the determining means, as well as means for comparing the wanted and the actual course of the edge and means for showing the results of said comparison.

1 8. Device according to claim 1 7, furthermore comprising means for arranging marks on the profile, which are controlled by the control means in response to the data of the scanning means.

1 9. Device according to claim 1 8, the marking means comprising an ink jet.

20. Device according to claim 1 9, the marking means also being controlled by the control means for printing a bar code on the profile.

21 . Device according to claim 20, the marking means comprising an ink or paint spray device.

22. Device comprising one or more of the characterizing measures described in the description and/or shown in the drawings.