Reconfigurable discrete die stretch bending accurate forming device for narrow table top, using method and stretch bending machine

Abstract

The invention discloses a reconfigurable discrete die stretch bending accurate forming device for a narrow table top, a using method and a stretch bender. In the forming device, a plurality of positioning grooves are uniformly formed in the upper end face of the front end of a workbench in the circumferential direction and used for mounting a mounting base at the front end of a longitudinal moving assembly; driving mechanisms of the longitudinal moving assemblies are installed at the rear end of the workbench, one die assembly is installed in each installation base, a die swing assembly is installed at the top end of each installation base, and a rotating shaft of each die swing assembly is fixedly connected with the corresponding die assembly. Moving a single mold assembly to a specified position, deflecting by a corresponding angle and keeping; theoretical shapes of stringers with different radiuses are formed on the end faces of the mold assemblies through multi-point fitting, the positions of the mold assemblies are kept locked in the stretch-bending forming process of the stretch-bending machine, and stretch-bending forming of the multiple stringers of the airplane is synchronously completed. The control system is used for controlling the longitudinal moving assemblies and the mold swing assemblies to move.

Description

Technical Field

[0001] The present invention relates to the field of aircraft manufacturing technology but is not limited thereto, and in particular to a reconfigurable discrete die stretch-bending precision forming device for a narrow table and a use method thereof, as well as a stretch-bending machine. Background Art

[0002] Aircraft T-section long stringers refer to aircraft metal profile parts with a "T"-shaped cross section and an irregular arc shape. They are mainly used to support and fix aircraft skins to ensure the stability of aircraft structures. Stretch-bending technology is a technology for stretching and bending profiles. It has the advantages of high bending precision and good forming quality, and has a wide range of applications.

[0003] The cross-sections of a certain aircraft profile are mainly L- and T-shaped, with nearly 200 items in total. The arc radius at different positions of the aircraft skin is different. The forming of each long stringer requires a set of traditional special stretch-bending forming molds. The number of stretch-bending molds is huge, resulting in high mold manufacturing costs and high warehouse storage management costs. A large amount of transportation costs will also be generated during the storage and retrieval process.

[0004] With the increasing number of aircraft models, the number of special bending dies for long stringers is also increasing. During the production process, for each long stringer forming, it is necessary to disassemble and install the special die on the corresponding bending machine. Repeated disassembly and installation will cause wear on the positioner of the bending machine, which will cause inaccurate positioning of the bending machine in the long term, and then cause the long stringer parts to be out of tolerance. Summary of the invention

[0005] Purpose of the present invention: In order to solve the above-mentioned technical problems, the embodiments of the present invention provide a reconfigurable discrete die stretch-bending precision forming device and a method of use for a narrow table, as well as a stretch-bending machine, to solve the existing stretch-bending method of aircraft stringers. Since the forming of each stringer usually requires a set of traditional special stretch-bending forming dies, the mold manufacturing cost is high, and the frequent disassembly and assembly of the special stretch-bending dies for the stringers on the stretch-bending machine causes wear on the stretch-bending machine.

[0006] Technical solution of the present invention: In a first aspect, an embodiment of the present invention provides a reconfigurable discrete die stretch-bending precision forming device for a narrow table, comprising: a longitudinal moving component 1, a die component 2, a die swing component 3, a workbench 4 and a control system 5;

[0007] The workbench 4 is fixedly mounted on the narrow table of the drawing and bending machine 6. The workbench 4 is configured as a stepped fan ring structure as a whole, including a front drawing and bending working part located away from the center of the circle and a rear mounting part located close to the center of the circle; the upper end surface of the front drawing and bending working part is uniformly arranged with a plurality of positioning grooves 42 in the radial direction along the circumferential direction;

[0008] A mounting seat 15 at the front end of the longitudinal moving assembly 1 is installed in each positioning groove 42 of the workbench 4, and a driving mechanism of each longitudinal moving assembly 1 is installed through the rear end mounting portion. A mold assembly 2 is installed in each mounting seat 15, and a mold swing assembly 3 is installed at the top of the mounting seat 15. The rotating shaft of the mold swing assembly 3 passes through the mounting seat 15 and is fixedly connected to the mold assembly 2;

[0009] A single mold assembly 2 is used to move to a specified position along the radial direction under the push of the longitudinal moving assembly 1 installed thereon, and to deflect to a corresponding angle and maintain the deflection angle driven by the connecting shaft of the mold swing assembly 3;

[0010] Under the posture adjustment of each group of longitudinal moving components 1 and mold swinging components 3 on the workbench 4, the end faces of each mold component 2 are formed into theoretical shapes of long stringers with different radii through multi-point fitting, and the positions of each mold component 2 are kept locked during the stretch bending forming process of the stretch bending machine 6, so as to synchronously complete the stretch bending forming of multiple long stringers of the aircraft;

[0011] The control system 5 is connected to the driving mechanisms in each mold swing assembly 3 and each longitudinal moving assembly 1 respectively, and is used to control the radial movement of each group of longitudinal moving assemblies 1 through the control system 5 to form an overall curvature trend of the long stringer to be stretched and bent, and control the rotation of each mold swing assembly 3 to drive the rotation of each mold assembly 2, so that the stretching and bending end surface of each mold assembly 2 cooperates with the stretching and bending surface of each section area on the long stringer at the corresponding position.

[0012] Optionally, in the reconfigurable discrete die stretch-bending precision forming device for a narrow table as described above,

[0013] A fan-shaped annular boss 41 is provided on the rear end mounting portion of the workbench 4, and a fan-shaped mounting step lower than the fan-shaped annular boss 41 is provided on one side of the fan-shaped annular boss 41 close to the front end bending working portion;

[0014] Each set of the longitudinal moving components 1 comprises: a motor 11, an integrated seat 12, a self-locking screw structure 13, a slider rail structure 14 and a mounting seat 15;

[0015] Among them, the slider-rail structure 14 is fixedly installed in the positioning groove 42 at the corresponding position in the workbench 4; the bottom of the mounting seat 15 is a flat plate structure and is fixedly connected to the slider sliding on the rail in the slider-rail structure 14; the bottom surface of the integral seat 12 is fixed on the fan-shaped mounting step at the front end of the boss 41 of the workbench 4, and its rear end surface is in close contact with the front side end surface of the boss 41, for resisting the pressure exerted during the forming of the aircraft stringer. The motor 11 is installed on the rear end surface of the integral seat 12, and the rear end of the self-locking lead screw structure 13 passes through the integral seat 12 and is connected to the driving shaft of the motor 11. The front end of the self-locking lead screw structure 13 is fixedly connected to the mounting seat 15 through a nut 131, and drives the mounting seat 15 to move radially along the positioning groove 42 under the drive of the motor 11.

[0016] Optionally, in a reconfigurable discrete die stretch bending precise forming device for a narrow workbench as described above, the mounting seat 15 includes: a fixed bottom plate, an intermediate vertical plate 151, and a top mounting part;

[0017] Among them, the mounting seat 15 is installed on the slider of the corresponding rail through the fixed bottom plate. The intermediate vertical plate 151 is vertically arranged in the middle of the fixed bottom plate. A through hole is provided on the intermediate vertical plate 151 for the front end of the self-locking lead screw structure 13 to pass through the through hole and be fixed by a nut 131. The top mounting part is set as a "C"-shaped structure 152 for semi-embedded sleeving and installing the mold assembly 2 through the "C"-shaped structure 152. A limiting boss 153 for installing the mold assembly 2 is provided on the upper surface of the lower end of the "C"-shaped structure 152. Coaxial holes are provided in the vertical direction on the upper and lower plates of the "C"-shaped structure 152 for installing the rotating shaft 35 of the mold swing assembly 3.

[0018] Optionally, in a reconfigurable discrete die stretch bending precise forming device for a narrow workbench as described above, each mold assembly includes: a mold head group 21, multiple groups of replacement part groups 22, and an adjustment plate 23;

[0019] Among them, the mold head group 21 includes: a male head 211 and a female head 212 which are installed in a relative and mating manner up and down. A through hole is provided at the rear end of the mold head group 21, and is connected to the rotating shaft 35 of the corresponding installed mold swing assembly 3 through interference fit, so that the mold assembly rotates around the axis of the rotating shaft 35. An adjustment plate 23 is clamped at the middle position of the male head 211 and the female head 212 for spacing adjustment;

[0020] Each group of the replacement part groups 22 includes an upper replacement part and a lower replacement part, which are correspondingly and fixedly installed on the front side end surfaces of the male head 211 and the female head 212;

[0021] The front side end surfaces of each group of the replacement part groups 22 are set as arc ends with different curvatures for cooperating with stringers of different materials and bending radii.

[0022] Optionally, in the reconfigurable discrete die stretch-bending precision forming device for a narrow table as described above,

[0023] Each set of the mold assembly 2 is used to adjust the gap between the male head 211 and the female head 212 through the adjustment plate 23 to match the clamping plate of the long stringer to be bent, and the clamping plate of the long stringer clamped by the upper replacement part and the lower replacement part, so as to be bent by the bending machine;

[0024] Wherein, for the T-shaped long stringer 71, the middle plate of its T-shaped portion is used as a clamping plate, and the middle area thereof is clamped between the upper replacement part and the lower replacement part of the mold assembly 2 located in the middle of the workbench 4;

[0025] For the L-shaped long stringer 72 , the short side plates thereof are used as clamping plates, and the middle area thereof is clamped between the upper replacement part and the lower replacement part of the mold assembly 2 located in the middle of the workbench 4 .

[0026] Optionally, in the reconfigurable discrete die stretch-bending precision forming device for a narrow table as described above, each of the die swing components 3 includes: a drag chain 31, a drag chain slot 32, a reduction motor seat 33, a reduction motor 34, and a rotating shaft 35;

[0027] The drag chain groove 32 is radially installed above the integrated seat 12 and the motor 11. The drag chain groove 32 is installed on the end surface of the workbench 4 through a support frame. The reduction motor 34 is installed on the top of the mounting seat 15 at the corresponding position through the reduction motor seat 33. The rotating shaft 35 of the reduction motor 34 passes through the reduction motor seat 33 and the mounting seat 15 and is fixedly connected to the mold assembly 2 at the corresponding position; the rear end of the drag chain 31 is fixed in the drag chain groove 32, and the front end is fixed on the reduction motor seat 34; the reduction motor 34 is arranged through the drag chain 31.

[0028] Optionally, in the reconfigurable discrete die stretch-bending precision forming device for a narrow table as described above,

[0029] The number of the positioning grooves 42, the longitudinal moving assembly 1, the mold assembly 2, and the mold swing assembly 3 arranged on the front end bending work portion of the workbench 4 is the same, and they are all set to an odd number; and the angle between adjacent positioning grooves 42 is not greater than 1.5°.

[0030] In a second aspect, an embodiment of the present invention further provides a stretch-bending machine for aircraft long stringers, comprising: a stretch-bending machine body, and a reconfigurable discrete die stretch-bending precision forming device for a narrow table as described in any one of the above items;

[0031] Among them, the two ends of the aircraft long stringer to be stretched and bent are respectively fixed on the stretching and bending machine, and a reconfigurable discrete die stretching and bending precision forming device is used to clamp the middle area of ​​the clamping end of the aircraft long stringer for stretching and bending, and the clamping end is gradually clamped in the direction from the middle to both sides during the stretching and bending process.

[0032] In a third aspect, an embodiment of the present invention further provides a method for using a reconfigurable discrete die bending precision forming device for a narrow table, wherein the method comprises the following steps: clamping an aircraft stringer with the reconfigurable discrete die bending precision forming device for a narrow table as described in any one of the above claims, and then performing a bending operation on a bending machine, comprising the following steps:

[0033] Step 1, according to the type, hardness and radius of the long stringer to be formed, select the matching replacement part group 22 in the mold assembly 2, and install it on the mold head group 21 of the mold assembly 2;

[0034] Step 2, after inputting the radius value of the long stringer to be formed through the control system 5, the radial driving motor in each group of longitudinal moving components 1 drives each mounting seat 15 to move to the position specified by the program, so that the longitudinal moving components 1 of the odd group are arranged in a symmetrical distribution on both sides with the middle group as the center line;

[0035] Step 3, control each group of mold swing components 3 through the control system 5 to drive the corresponding connected mold components 2 to rotate, so that the mold components 2 installed on the mounting seat 15 of the longitudinal moving component 1 located in the middle position remain stationary, and the mold components 2 on both sides rotate symmetrically to the angle specified by the program, and under the motion control of the longitudinal moving component 1 and the mold swing component 3, the bending end faces of the replacement part groups 22 in all mold components 2 are combined at multiple points to form the theoretical shape of the long stringer to be formed;

[0036] Step 4, fix the long stringer on the stretching and bending machine, and gradually bring the long stringer close to the mold assembly 2 of the forming device through the control system. First, use the mold assembly 2 in the middle position to clamp the middle area of ​​the long stringer clamping plate, and then clamp symmetrically on both sides of the center line in sequence. As the stretching and bending of the long stringer proceeds, the long stringer will gradually bend until it is completely in contact with the stretching and bending end faces of the front replacement part groups 22 of all mold assemblies 2;

[0037] Step 5. After completing the current long girder bending and forming, repeat steps 1 to 4 when performing the next long girder bending and forming.

[0038] Beneficial effects of the invention: The embodiments of the invention provide a reconfigurable discrete die stretch-bending precision forming device for a narrow table and a method of use, as well as a stretch-bending machine. The main purpose is to solve the problem of a huge number of traditional stretch-bending forming dies and high costs, and at the same time utilize the existing stretch-bending machine to establish a reconfigurable discrete die stretch-bending precision forming device. The reconfigurable discrete die bending precision forming device provided by the embodiment of the present invention can adjust the gap and posture of the die assembly so that the die envelope surface formed by the end face can adapt to the bending forming of different curvatures and different cross-sections. This method can greatly reduce the number of bending dies, shorten the manufacturing cycle of bending parts, and reduce manufacturing costs. The end density arrangement of the die assembly uniformly distributed at a preset angle and the arc approximation of the bending end face of the replacement part group 22 at the front end of the die assembly can achieve the requirement that the profile surface forming step difference is not greater than 0.05 mm. The replaceable form of the replacement part group 22 at the front end of the die assembly can achieve rebound compensation for different bending profiles, thereby ensuring high-quality bending forming of aircraft long stringer parts. The die swing assembly 3 can rotate each die assembly to different angles to achieve surface contact with the profile using a larger arc, thereby achieving the bending requirements of long strings with a large curvature range on a narrow table. The reconfigurable discrete die bending precision forming device provided by the present invention can be extended to all aircraft long stringer multi-point precision forming technical fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0040] Figure 1 A schematic diagram of the overall structure of a reconfigurable discrete die stretch-bending precision forming device for a narrow table provided by an embodiment of the present invention;

[0041] Figure 2 for Figure 1 A schematic diagram of the structure of a workbench in a reconfigurable discrete die stretch-bending precision forming device for a narrow table provided by the illustrated embodiment;

[0042] Figure 3 for Figure 1 A schematic diagram of the structure of a workbench and a single longitudinal moving group in a reconfigurable discrete die stretch-bending precision forming device for a narrow table provided by the illustrated embodiment;

[0043] Figure 4 for Figure 1 A schematic diagram of the structure of a mounting seat in a reconfigurable discrete die stretch-bending precision forming device for a narrow table provided by the illustrated embodiment;

[0044] Figure 5 for Figure 1Schematic diagram of the structure of the die assembly in the reconfigurable discrete die stretch bending precise forming device for a narrow tabletop provided by the illustrated embodiment;

[0045] Figure 6 For Figure 5 Schematic diagram of the structure of the die assembly for assembling a T-shaped longeron provided by the illustrated embodiment;

[0046] Figure 7 For Figure 5 Schematic diagram of the structure of the die assembly for assembling an L-shaped longeron provided by the illustrated embodiment;

[0047] Figure 8 For Figure 1 Schematic diagram of the structure of the die swing assembly in the reconfigurable discrete die stretch bending precise forming device for a narrow tabletop provided by the illustrated embodiment.

[0048] Explanation of reference numerals:

[0049] 1 Longitudinal movement assembly; 11 Motor; 12 Integral seat; 13 Self-locking lead screw structure; 131 Nut; 14 Slide block and slide rail structure; 15 Mounting seat; 151 Intermediate vertical plate; 152 "C"-shaped structure; 153 Limit boss; 2 Die assembly; 21 Die head group; 211 Male head; 212 Female head; 22 Replacement end face; 23 Adjustment and installation plate; 3 Die swing assembly; 31 Drag chain; 32 Drag chain groove; 33 Reducing motor seat; 34 Reducing motor; 35 Rotating shaft; 4 Workbench; 41 Annular convex platform; 42 Positioning groove; 5 Control system; 6 Stretch bender; 71 T-shaped longeron; 72 L-shaped longeron. Detailed implementation manners

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, without conflict, the embodiments and features in the embodiments of this application can be combined arbitrarily with each other.

[0051] As already described in the above background art, the longerons at various positions of the aircraft need to be stretch bent into different arcs by using stretch bending forming technology. The existing stretch bending methods have the following problems:

[0052] On the one hand, for the forming of each longeron, usually a set of traditional special stretch bending forming dies is required, and the number of stretch bending dies is huge, resulting in high die manufacturing costs;

[0053] On the other hand, during the production process, for the forming of each longeron, the disassembly and installation of the special die need to be carried out on the corresponding stretch bending machine tool. The repeated disassembly and installation positioning will cause wear to the positioner of the stretch bending machine tool. In the long run, it will lead to inaccurate positioning of the stretch bending machine tool, and further cause the longeron parts to be out of tolerance;

[0054] On the other hand, since the thickness of each set of special bending dies is different, the height position of the bending dies needs to be adjusted according to the position of the bending chuck during installation, which is inconvenient to operate and has low manufacturing efficiency.

[0055] The multi-point forming (MPF) process is an improvement on the traditional forming method. According to the idea of ​​discretization, the traditional integral mold is divided into a series of basic bodies with regular arrangement and adjustable positions. Each basic body can be independently controlled by a CNC adjustment system. The different composition of each basic body will construct a forming surface with different profile bending.

[0056] The forming quality requirements for aircraft long stringer parts must meet two dimensions, namely shape accuracy and surface quality. The main influencing factors are: profile discrete method and bending process parameters. A certain aircraft requires that the surface step difference indentation of long stringer parts after bending must be greater than 0.05mm, which places high demands on the bending discrete layout and the fitting degree of the die head. At present, there are few practical applications of reconfigurable discrete die bending precision forming technology for aircraft long stringer parts, and it cannot meet the forming quality requirements of aircraft parts.

[0057] Considering the combination and utilization of the existing bending machine, the present invention develops a flexible bending die by studying the flexible bending forming method of the basic body composed of discrete bending forming dies under the existing bending machine. That is, the embodiment of the present invention provides a reconfigurable discrete die bending precision forming device for a narrow table and a method of use, which can realize a discrete die bending precision forming device with a large curvature range adjustable on the limited width table of the bending machine, reduce the number of tooling, and solve the two problems of die structure design and part forming quality control.

[0058] The present invention provides the following specific embodiments which can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0059] Figure 1 A schematic diagram of the overall structure of a reconfigurable discrete die stretch-bending precision forming device for a narrow table provided by an embodiment of the present invention; Figure 2 for Figure 1 The illustrated embodiment provides a schematic diagram of the structure of a workbench in a reconfigurable discrete die stretch-bending precision forming device for a narrow table. Figure 1 and Figure 2 The embodiment of the present invention provides a reconfigurable discrete die stretch-bending precision forming device for a narrow table, comprising: a longitudinal moving component 1, a die component 2, a die swinging component 3, a workbench 4 and a control system 5.

[0060] like Figure 1 and Figure 2As shown, in the embodiment of the present invention, the workbench 4 is fixedly installed on the narrow table surface of the stretch bending machine 6. The workbench 4 is arranged as a stepped fan ring structure as a whole, including a front end stretching and bending working part located on the side away from the center of the circle and a rear end mounting part located on the side close to the center of the circle; the upper end surface of the front end stretching and bending working part is uniformly arranged with a plurality of positioning grooves 42 in the radial direction along the circumferential direction.

[0061] Figure 3 for Figure 1 The illustrated embodiment provides a schematic diagram of the structure of a workbench and a single longitudinal moving group in a reconfigurable discrete die stretch-bending precision forming device for a narrow table. Figure 1 , Figure 2 , Figure 3 In the embodiment of the present invention, a mounting seat 15 at the front end of the longitudinal moving component 1 is installed in each positioning groove 42 of the workbench 4, and a driving mechanism of each longitudinal moving component 1 is installed through the rear end mounting portion, a mold assembly 2 is installed in each mounting seat 15, a mold swinging assembly 3 is installed at the top of the mounting seat 15, and a rotating shaft of the mold swinging assembly 3 passes through the mounting seat 15 and is fixedly connected to the mold assembly 2.

[0062] See also Figure 1 As shown, a single mold assembly 2 is used to move radially to a specified position under the push of the longitudinal moving assembly 1 installed thereon, and to deflect to a corresponding angle and maintain the deflection angle driven by the connecting shaft of the mold swing assembly 3.

[0063] Under the posture adjustment of each group of longitudinal moving components 1 and mold swinging components 3 on the workbench 4 in the embodiment of the present invention, the end faces of each mold component 2 form the theoretical shapes of long stringers with different radii through multi-point fitting, and the positions of each mold component 2 are kept locked during the stretch-bending forming process of the stretch-bending machine 6, thereby completing the stretch-bending forming of multiple long stringers of the aircraft synchronously.

[0064] The control system 5 in the embodiment of the present invention is respectively connected to the driving mechanisms in each mold swing assembly 3 and each longitudinal moving assembly 1, and is used to control the radial movement of each group of longitudinal moving assemblies 1 through the control system to form an overall curvature trend of the long stringer to be stretched and bent, and control the rotation of each mold swing assembly 3 to drive the rotation of each mold assembly 2, so that the stretching and bending end surface of each mold assembly 2 cooperates with the stretching and bending profile of each section area on the long stringer at the corresponding position.

[0065] In one implementation of the embodiment of the present invention, see Figure 2 As shown, a fan-shaped annular boss 41 is provided on the rear end mounting portion of the workbench 4, and a fan-shaped mounting step lower than the fan-shaped annular boss 41 is provided on one side of the fan-shaped annular boss 41 close to the front end bending working portion.

[0066] See also Figure 2 , Figure 3, each set of longitudinal movement components 1 in this implementation method includes: a motor 11, an integral seat 12, a self-locking lead screw structure 13, a slider rail structure 14, and a mounting seat 15.

[0067] In this implementation method, the slider rail structure 14 is fixedly installed in the positioning groove 42 at the corresponding position in the workbench 4; the bottom of the mounting seat 15 is a flat plate structure and is fixedly connected to the slider sliding on the rail in the slider rail structure 14; the bottom surface of the integral seat 12 is fixed on the sector-shaped mounting step at the front end of the boss 41 of the workbench 4, and its rear end surface is in close contact with the front side end surface of the boss 41 to resist the pressure exerted during the forming of the aircraft stringer. The motor 11 is installed on the rear end surface of the integral seat 12. The rear end of the self-locking lead screw structure 13 passes through the integral seat 12 and is connected to the driving shaft of the motor 11. The front end of the self-locking lead screw structure 13 is fixedly connected to the mounting seat 15 through a nut 131, and drives the mounting seat 15 to move radially along the positioning groove 42 under the drive of the motor 11.

[0068] In one implementation method of the embodiment of the present invention, an implementation scheme of the mounting seat 15 is provided. Figure 4 For Figure 1 the structural schematic diagram of the mounting seat in the reconfigurable discrete die stretch bending precision forming device for a narrow tabletop provided in the shown embodiment. Refer to Figure 3 、 Figure 4 As shown, the mounting seat 15 includes: a fixed bottom plate, an intermediate vertical plate 151, and a top mounting part.

[0069] In this implementation method, the mounting seat 15 is installed on the slider of the corresponding rail through the fixed bottom plate. The intermediate vertical plate 151 is vertically arranged in the middle of the fixed bottom plate. A through hole is provided on the intermediate vertical plate 151 for the front end of the self-locking lead screw structure 13 to pass through and be fixed by a nut 131. The top mounting part is set as a "C"-shaped structure 152 for semi-embedded sleeving and installing the die assembly 2 through the "C"-shaped structure 152. A limiting boss 153 for installing the die assembly 2 is provided on the upper surface of the lower end of the "C"-shaped structure 152. Coaxial holes are provided in the vertical direction on the upper and lower plates of the "C"-shaped structure 152 for installing the rotating shaft 35 of the die swing assembly 3.

[0070] In one implementation method of the embodiment of the present invention, an implementation scheme of the die assembly 2 is provided. Refer to Figure 5 、 Figure 6 、 Figure 7 , each die assembly 2 includes: a die head group 21, multiple groups of replacement part groups 22, and an adjustment plate 23. Figure 5 For Figure 1 the structural schematic diagram of the die assembly in the reconfigurable discrete die stretch bending precision forming device for a narrow tabletop provided in the shown embodiment;

[0071] Figure 6for Figure 5 A schematic structural diagram of a mold assembly provided in the illustrated embodiment and assembled with a T-shaped long stringer;

[0072] Figure 7 for Figure 5 The illustrated embodiment provides a schematic structural diagram of a mold assembly assembled with an L-shaped long stringer.

[0073] In this implementation, the mold head group 21 includes: a male head 211 and a female head 212 that are installed in a relatively matched manner at the upper and lower ends. A through hole is opened at the rear end of the mold head group 21, which is connected to the rotating shaft 35 of the corresponding mold swing assembly 3 through an interference fit, so that the mold assembly can rotate axially around the rotating shaft 35. An adjustment plate 23 is clamped in the middle position of the male head 211 and the female head 212 for spacing adjustment.

[0074] Each replacement part group 22 includes an upper replacement part and a lower replacement part, which are fixedly mounted on the front end faces of the male head 211 and the female head 212. In addition, the front end faces of each replacement part group 22 are set as arc ends with different curvatures to match long beams with different materials and bending radii.

[0075] based on Figure 5 The illustrated embodiment provides a mold assembly 2 structure, and in this implementation, each set of mold assemblies 2 is used as follows: the gap between the male head 211 and the female head 212 is adjusted by the adjustment plate 23 to match the clamping plate of the long beam to be bent, and the clamping plate of the long beam is clamped by the upper replacement part and the lower replacement part, so as to perform bending by a bending machine.

[0076] One application of the mold assembly 2 in this implementation is: for the T-shaped long stringer 71, the middle plate of its T-shaped part is used as a clamping plate, and the middle area thereof is clamped between the upper replacement part and the lower replacement part of the mold assembly 2 located in the middle of the workbench 4. Figure 6 The assembly structure of the T-shaped long stringer 71 on the mold assembly 2 is shown.

[0077] Another application of the mold assembly 2 in this implementation is: for the L-shaped long stringer 72, its short side plate is used as a clamping plate, and the middle area thereof is clamped between the upper replacement part and the lower replacement part of the mold assembly 2 located in the middle of the workbench 4. Figure 7 The illustrated assembly structure of the L-shaped long stringer 72 on the mold assembly 2 .

[0078] In one implementation of the embodiment of the present invention, an implementation scheme of the mold swing assembly 3 is provided. Figure 8 for Figure 1 The embodiment shown is a schematic diagram of the structure of the die swing assembly in the reconfigurable discrete die stretch bending precision forming device for narrow table. Figure 3 , Figure 8Each mold swing assembly 3 in this implementation includes: a drag chain 31, a drag chain slot 32, a reduction motor seat 33, a reduction motor 34, and a rotating shaft 35.

[0079] In this implementation, the drag chain groove 32 is installed radially above the integrated seat 12 and the motor 11, the drag chain groove 32 is installed on the end surface of the workbench 4 through the support frame, the reduction motor 34 is installed on the top of the mounting seat 15 at the corresponding position through the reduction motor seat 33, and the rotating shaft 35 of the reduction motor 34 passes through the reduction motor seat 33 and the mounting seat 15 and is fixedly connected to the mold assembly 2 at the corresponding position; the rear end of the drag chain 31 is fixed in the drag chain groove 32, and the front end is fixed on the reduction motor seat 34; the reduction motor 34 is arranged through the drag chain 31.

[0080] The above-mentioned embodiments of the present invention provide a reconfigurable discrete die bending precision forming device for a narrow table. In a specific implementation, the number of positioning grooves 42, longitudinal moving components 1, mold components 2, and mold swing components 3 provided on the front end bending working part of the workbench 4 is the same, and are all set to an odd number; and the angle between adjacent positioning grooves 42 is not greater than 1.5°.

[0081] Based on the above embodiment of the present invention, the reconfigurable discrete die bending precision forming device for narrow tabletop is provided. Figure 1 An embodiment of the present invention further provides a bending machine for aircraft long stringers, comprising: a bending machine body 6, and a reconfigurable discrete die bending precision forming device for a narrow tabletop as provided in any of the above embodiments.

[0082] Among them, the two ends of the aircraft long stringer to be stretched and bent are respectively fixed on the stretching and bending machine 6, and a reconfigurable discrete die stretching and bending precision forming device is used to clamp the middle area of ​​the clamping end of the aircraft long stringer for stretching and bending, and the clamping end is gradually clamped in the direction from the middle to both sides during the stretching and bending process.

[0083] Based on the reconfigurable discrete die bending precision forming device for narrow tabletops provided in the above embodiments of the present invention, the embodiments of the present invention further provide a method for using the reconfigurable discrete die bending precision forming device for narrow tabletops. Specifically, the method for using the reconfigurable discrete die bending precision forming device for narrow tabletops provided in any of the above embodiments to clamp the aircraft stringer and then perform bending operation on a bending machine comprises the following steps:

[0084] Step 1, according to the type, hardness and radius of the long stringer to be formed, select the matching replacement part group 22 in the mold assembly 2, and install it on the mold head group 21 of the mold assembly 2;

[0085] Step 2, after inputting the radius value of the long stringer to be formed through the control system 5, the radial driving motor in each group of longitudinal moving components 1 drives each mounting seat 15 to move to the position specified by the program, so that the longitudinal moving components 1 of the odd group are arranged in a symmetrical distribution on both sides with the middle group as the center line;

[0086] Step 3, control each group of mold swing components 3 through the control system 5 to drive the corresponding connected mold components 2 to rotate, so that the mold components 2 installed on the mounting seat 15 of the longitudinal moving component 1 located in the middle position remain stationary, and the mold components 2 on both sides rotate symmetrically to the angle specified by the program, and under the motion control of the longitudinal moving component 1 and the mold swing component 3, the bending end faces of the replacement part groups 22 in all mold components 2 are combined at multiple points to form the theoretical shape of the long stringer to be formed;

[0087] Step 4, fix the long stringer on the stretching and bending machine, and gradually bring the long stringer close to the mold assembly 2 of the forming device through the control system. First, use the mold assembly 2 in the middle position to clamp the middle area of ​​the long stringer clamping plate, and then clamp symmetrically on both sides of the center line in sequence. As the stretching and bending of the long stringer proceeds, the long stringer will gradually bend until it is completely in contact with the stretching and bending end faces of the front replacement part groups 22 of all mold assemblies 2;

[0088] Step 5. After completing the current long girder bending and forming, repeat steps 1 to 4 when performing the next long girder bending and forming.

[0089] The embodiment of the present invention uses the narrow table of the existing bending machine to establish a reconfigurable discrete die bending precision forming device. The gap of the die assembly is adjustable, and the posture position is adjustable, so that the die envelope formed by the end face can adapt to the bending forming of different curvatures and different cross-sections. This method can greatly reduce the number of bending dies, shorten the manufacturing cycle of bending parts, and reduce manufacturing costs; using the die head body uniformly distributed at 1.5° to meet the density arrangement requirements of the profile bending, and through the replaceable end face of the die head body end face, the rebound compensation of the bending profile is realized, ensuring the high-quality bending forming of aircraft long stringer parts. It can be directly extended to all aircraft long stringer multi-point precision forming technology fields.

[0090] The embodiment of the present invention provides a reconfigurable discrete die stretch-bending precision forming device for a narrow table and a method of use, the main purpose of which is to solve the problem of a huge number of traditional stretch-bending forming dies and high costs, and at the same time utilize the existing stretch-bending machine to establish a reconfigurable discrete die stretch-bending precision forming device. The reconfigurable discrete die bending precision forming device provided by the embodiment of the present invention can adjust the gap and posture of the die assembly so that the die envelope surface formed by the end face can adapt to the bending forming of different curvatures and different cross-sections. This method can greatly reduce the number of bending dies, shorten the manufacturing cycle of bending parts, and reduce manufacturing costs. The end density arrangement of the die assembly uniformly distributed at a preset angle and the arc approximation of the bending end face of the replacement part group 22 at the front end of the die assembly can achieve the requirement that the profile surface forming step difference is not greater than 0.05 mm. The replaceable form of the replacement part group 22 at the front end of the die assembly can achieve rebound compensation for different bending profiles, thereby ensuring high-quality bending forming of aircraft long stringer parts. The die swing assembly 3 can rotate each die assembly to different angles to achieve surface contact with the profile using a larger arc, thereby achieving the bending requirements of long strings with a large curvature range on a narrow table. The reconfigurable discrete die bending precision forming device provided by the present invention can be extended to all aircraft long stringer multi-point precision forming technical fields.

[0091] Although the embodiments disclosed in the present invention are as above, the contents are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A reconfigurable discrete die stretch bending precision forming device for narrow table, characterized in that: include: A longitudinal moving component (1), a mold component (2), a mold swinging component (3), a workbench (4) and a control system (5); The workbench (4) is fixedly mounted on a narrow tabletop of a bending machine (6); the workbench (4) is configured as a stepped fan ring structure, comprising a front bending working portion located away from the center of the circle and a rear mounting portion located close to the center of the circle; a plurality of positioning grooves (42) are evenly arranged in the radial direction on the upper end surface of the front bending working portion along the circumferential direction; A mounting seat (15) at the front end of the longitudinal moving assembly (1) is installed in each positioning groove (42) of the workbench (4), and a driving mechanism of each longitudinal moving assembly (1) is installed through a rear end mounting portion, a mold assembly (2) is installed in each mounting seat (15), a mold swing assembly (3) is installed at the top end of the mounting seat (15), and a rotating shaft of the mold swing assembly (3) passes through the mounting seat (15) and is fixedly connected to the mold assembly (2); A single mold assembly (2) is used to move radially to a specified position under the push of the longitudinal moving assembly (1) installed thereon, and to deflect to a corresponding angle and maintain the deflection angle under the drive of the connecting shaft of the mold swing assembly (3); Under the posture adjustment of each group of longitudinal moving components (1) and mold swing components (3) on the workbench (4), the end faces of each mold component (2) are formed into theoretical shapes of long strings with different radii through multi-point fitting, and the positions of each mold component (2) are kept locked during the stretch-bending forming process of the stretch-bending machine (6), so as to synchronously complete the stretch-bending forming of multiple long strings of the aircraft; The control system (5) is respectively connected to the driving mechanisms in each mold swing assembly (3) and each longitudinal moving assembly (1), and is used to control each group of longitudinal moving assemblies (1) to move in the radial direction through the control system (5) to form an overall curvature trend of the long stringer to be bent, and to control the rotation of each mold swing assembly (3) to drive the rotation of each mold assembly (2), so that the bending end surface of each mold assembly (2) matches the bending profile of each section area on the long stringer at a corresponding position.

2. A reconfigurable discrete die stretch-bending precision forming device for narrow tabletops as claimed in claim 1, characterized in that: A fan-shaped annular boss (41) is provided on the rear end mounting portion of the workbench (4), and a fan-shaped mounting step lower than the fan-shaped annular boss (41) is provided on one side of the fan-shaped annular boss (41) close to the front end bending working portion; Each set of the longitudinal moving components (1) comprises: a motor (11), an integrated seat (12), a self-locking screw structure (13), a slider rail structure (14) and a mounting seat (15); Among them, the slider-rail structure (14) is fixedly installed in the positioning groove (42) at the corresponding position in the workbench (4); the bottom of the mounting seat (15) is a flat plate structure and is fixedly connected to the slider sliding on the rail in the slider-rail structure (14); the bottom surface of the integral seat (12) is fixed on the fan-shaped mounting step at the front end of the boss (41) of the workbench (4), and its rear end surface is in close contact with the front side end surface of the boss (41) to resist the pressure exerted during the forming of the aircraft stringer. The motor (11) is installed on the rear end surface of the integral seat (12), and the rear end of the self-locking lead screw structure (13) passes through the integral seat (12) and is connected to the drive shaft of the motor (11). The front end of the self-locking lead screw structure (13) is fixedly connected to the mounting seat (15) through a nut (131), and drives the mounting seat (15) to move radially along the positioning groove (42) under the drive of the motor (11).

3. A reconfigurable discrete die stretch-bending precision forming device for narrow tabletops as claimed in claim 2, characterized in that: The mounting seat (15) includes: a fixed bottom plate, an intermediate vertical plate (151), and a top mounting part; Among them, the mounting seat (15) is installed on the slider of the corresponding rail through the fixed bottom plate. The intermediate vertical plate (151) is vertically arranged in the middle of the fixed bottom plate. A through hole is provided on the intermediate vertical plate (151) for the front end of the self-locking lead screw structure (13) to pass through the through hole and be fixed by a nut (131). The top mounting part is arranged in a "C" shape structure (152) for semi-embedded sleeving and installing the die assembly (2) through the "C" shape structure (152). A limit boss (153) for installing the die assembly (2) is provided on the upper surface of the lower end of the "C" shape structure (152). Coaxial holes are provided in the vertical direction on the upper and lower plates of the "C" shape structure (152) for installing the rotating shaft (35) of the die swing assembly (3).

4. A reconfigurable discrete die stretch-bending precision forming device for narrow tabletops as claimed in claim 1, characterized in that: Each die assembly (2) includes: a die head group (21), multiple groups of replacement part groups (22), and an adjustment plate (23); Among them, the die head group (21) includes a male head (211) and a female head (212) which are installed in a relative and cooperative manner up and down. A through hole is provided at the rear end of the die head group (21), and is connected to the rotating shaft (35) of the corresponding installed die swing assembly (3) through interference fit, so that the die assembly rotates around the axis of the rotating shaft (35). An adjustment plate (23) is clamped between the middle positions of the male head (211) and the female head (212) for spacing adjustment; Each group of the replacement part group (22) includes an upper replacement part and a lower replacement part, which are correspondingly and fixedly installed on the front side end faces of the male head (211) and the female head (212); The front side end faces of each group of the replacement part group (22) are set as arc ends with different curvatures for cooperating with stringers of different materials and bending radii.

5. The reconfigurable discrete die stretch bending precise forming device for a narrow workbench according to claim 4, characterized in that Each die assembly (2) is used to adjust the gap between the male head (211) and the female head (212) through the adjustment plate (23) to cooperate with the clamping plate of the stringer to be stretch bent, and to clamp the clamping plate of the stringer through the upper replacement part and the lower replacement part, so as to perform stretch bending through a stretch bender. Wherein, for the T-shaped long stringer (71), the middle plate of its T-shaped part is used as a clamping plate, and the middle area thereof is clamped between the upper replacement part and the lower replacement part of the mold assembly (2) located in the middle of the workbench (4); For the L-shaped long stringer (72), its short side plates are used as clamping plates, and its central area is clamped between the upper replacement part and the lower replacement part of the mold assembly (2) located in the middle of the workbench (4).

6. A reconfigurable discrete die stretch-bending precision forming device for narrow tabletops as claimed in claim 2, characterized in that: Each of the mold swinging components (3) comprises: a drag chain (31), a drag chain slot (32), a reduction motor seat (33), a reduction motor (34), and a rotating shaft (35); The drag chain groove (32) is radially mounted above the integrated seat (12) and the motor (11); the drag chain groove (32) is mounted on the end surface of the workbench (4) through a support frame; the reduction motor (34) is mounted on the top of the mounting seat (15) at the corresponding position through the reduction motor seat (33); the rotating shaft (35) of the reduction motor (34) passes through the reduction motor seat (33) and the mounting seat (15) and is fixedly connected to the mold assembly (2) at the corresponding position; the rear end of the drag chain (31) is fixed in the drag chain groove (32) and the front end is fixed on the reduction motor seat (34); the reduction motor (34) is arranged through the drag chain (31).

7. A reconfigurable discrete die stretch-bending precision forming device for a narrow table as claimed in any one of claims 1 to 6, characterized in that: The number of positioning grooves (42), longitudinal moving components (1), mold components (2), and mold swing components (3) provided on the front end drawing and bending working part of the workbench (4) is the same, and is set to an odd number; and the angle between adjacent positioning grooves (42) is not greater than 1.5°.

8. A bending machine for aircraft long stringers, characterized in that: include: A stretch-bending machine body, and a reconfigurable discrete die stretch-bending precision forming device for a narrow table as claimed in any one of claims 1 to 7; Among them, the two ends of the aircraft long stringer to be stretched and bent are respectively fixed on the stretching and bending machine, and a reconfigurable discrete die stretching and bending precision forming device is used to clamp the middle area of ​​the clamping end of the aircraft long stringer for stretching and bending, and the clamping end is gradually clamped in the direction from the middle to both sides during the stretching and bending process.

9. A method for using a reconfigurable discrete die stretch bending precision forming device for a narrow table, characterized in that: A method for performing a bending operation on a bending machine after clamping an aircraft stringer using a reconfigurable discrete die bending precision forming device for a narrow table as claimed in any one of claims 1 to 7 comprises the following steps: Step 1, according to the type, hardness and radius of the long stringer to be formed, select a matching replacement part group (22) in the mold assembly (2), and install it on the mold head group (21) of the mold assembly (2); Step 2, after inputting the radius value of the long stringer to be formed through the control system (5), the radial driving motor in each group of longitudinal moving components (1) drives each mounting seat (15) to move to the position specified by the program, so that the longitudinal moving components (1) of the odd group are arranged in a symmetrical distribution on both sides with the middle group as the center line; Step 3, controlling each group of mold swinging components (3) through a control system (5) to drive the corresponding connected mold components (2) to rotate, so that the mold components (2) installed on the mounting seat (15) of the longitudinal moving component (1) located in the middle position remain stationary, and the mold components (2) on both sides are symmetrically rotated to the angle specified by the program, and under the motion control of the longitudinal moving component (1) and the mold swinging component (3), the bending end faces of the replacement part groups (22) in all mold components (2) are combined at multiple points to form the theoretical shape of the long stringer to be formed; Step 4, fix the long stringer on the bending machine, and make the long stringer gradually approach the mold assembly (2) of the forming device through the control system, first use the mold assembly (2) in the middle position to clamp the middle area of ​​the long stringer clamping plate, and then clamp symmetrically along both sides of the center line in sequence, as the bending of the long stringer proceeds, the long stringer will gradually bend until it is completely in contact with the bending end faces of the front replacement part group (22) of all the mold assemblies (2); Step 5. After completing the current long girder bending and forming, repeat steps 1 to 4 when performing the next long girder bending and forming.

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