Stretch bending forming preheating device and stretch bending method

Abstract

The invention relates to the technical field of stretch bending forming, and particularly discloses a stretch bending forming preheating device and a stretch bending method.The stretch bending forming preheating device comprises a base, a preheating part, a stamping part, a stretch bending part and a controller. Before the to-be-stretch-bent workpiece is stretch-bent, the to-be-stretch-bent workpiece can be preheated through the preheating part, then the preheated to-be-stretch-bent workpiece drives the movable stamping die core to extrude towards the fixed stamping die core through the first driving assembly, and therefore the to-be-stretch-bent workpiece is stamped; the to-be-stretch-bent workpiece is stretch-bent through the first stretch-bending assembly and the second stretch-bending assembly, so that the purpose of stretch-bending the to-be-stretch-bent workpiece is achieved, the problem that the to-be-stretch-bent workpiece is prone to springback due to the fact that the rigidity of the to-be-stretch-bent workpiece is too large and direct stretch-bending is conducted is solved, and meanwhile the to-be-stretch-bent workpiece can be continuously shaped after being stretch-bent during stamping; the stretch-bending forming preheating device effectively solves the problem that in the prior art, a stretch-bending forming preheating device lacks an effective preheating link, and consequently springback exists during stretch-bending operation.

Description

Technical Field

[0001] The present invention relates to the technical field of stretch-bending forming, and particularly to a preheating device for stretch-bending forming and a stretch-bending method. Background Art

[0002] Currently, when performing stretch-bending forming on high-strength steel, many challenges are faced. Due to its excessive rigidity, if high-strength steel is directly stretch-bent, springback is very likely to occur. Among them, the springback phenomenon not only makes it difficult to control the dimensional accuracy of the workpiece and fails to meet the design requirements, but may also affect the overall quality and performance of the workpiece, increase the rejection rate, and raise the production cost. For example, when manufacturing key components such as the body frame of subway vehicles, the springback phenomenon may cause deviations in the assembly of the frame, affecting the overall structural strength and appearance quality of the vehicle.

[0003] To solve the problem of springback in stretch-bending of high-strength steel, usually, the method of increasing the stretch-bending force during the stretch-bending process is adopted to overcome the springback, but this method often has poor effects and is likely to cause excessive deformation or even rupture of the steel; in related technologies, when performing stretch-bending forming on high-strength steel, most lack an effective preheating link and cannot fundamentally change the mechanical properties of the steel, resulting in springback problems during the stretch-bending operation. Summary of the Invention

[0004] The purpose of the present invention is to provide a preheating device for stretch-bending forming and a stretch-bending method to solve the problem that the existing preheating device for stretch-bending forming lacks an effective preheating link, resulting in springback during the stretch-bending operation.

[0005] On the one hand, the present invention provides a preheating device for stretch-bending forming, which includes: a base; a preheating part arranged on the base and capable of preheating the workpiece to be stretch-bent; a stamping part including a first driving component, a moving stamping die core and a fixed stamping die core, the fixed stamping die core is arranged on the base, and the first driving component is drivingly connected to the moving stamping die core to stamp the workpiece to be stretch-bent located between the moving stamping die core and the fixed stamping die core; a stretch-bending part including a first stretch-bending component and a second stretch-bending component rotatably arranged on both sides of the base, the first stretch-bending component and the second stretch-bending component respectively clamp both ends of the workpiece to be stretch-bent and are capable of stretch-bending the workpiece to be stretch-bent; a controller arranged on the base, the preheating part, the first driving component, the first stretch-bending component and the second stretch-bending component are all communicatively connected to the controller, and the controller controls the preheating part, the first driving component, the first stretch-bending component and the second stretch-bending component to work.

[0006] As an alternative technical solution of the preheating device for stretch bending forming, the preheating device for stretch bending forming further includes a first heating element and a second heating element. The first heating element is arranged on one side of the moving stamping die core facing the fixed stamping die core, and the second heating element is arranged on one side of the fixed stamping die core facing the moving stamping die core. Both the first heating element and the second heating element can heat the workpiece to be stretch bent.

[0007] As an alternative technical solution of the preheating device for stretch bending forming, the preheating part includes a heat insulation plate and a heater. The heat insulation plate is arranged on the base, and the heat insulation plate has a preheating groove for accommodating the workpiece to be stretch bent. The heater is arranged on the heat insulation plate, and the controller is electrically connected to the heater. The controller controls the heater to preheat the workpiece to be stretch bent located in the preheating groove.

[0008] As an alternative technical solution of the preheating device for stretch bending forming, the preheating part further includes a refractory layer. The heater includes a heating wire and a heater body. The heater body is arranged on the heat insulation plate and is electrically connected to the heating wire. The refractory layer is arranged on the preheating groove, and the heating wire is arranged on the refractory layer. The heating wire can preheat the workpiece to be stretch bent.

[0009] As an alternative technical solution of the preheating device for stretch bending forming, the first driving assembly includes a driving part, a pushing part and an elastic connecting piece. One end of the elastic connecting piece is slidably arranged on the pushing part, and the other end is arranged on the moving stamping die core. The driving part and the pushing part are drivingly connected to drive the pushing part to drive the moving stamping die core to move.

[0010] As an alternative technical solution of the preheating device for stretch bending forming, the stamping part further includes a pressure sensor arranged between the driving part and the pushing part. The pressure sensor is used to detect the stamping pressure.

[0011] As an alternative technical solution of the preheating device for stretch bending forming, the first stretch bending assembly includes a stretching arm, a second driving assembly and a clamping piece. The second driving assembly is rotatably arranged on the stretching arm. The second driving assembly and the clamping piece are drivingly connected so that the clamping piece tightens one end of the workpiece to be stretch bent. The stretching arm is rotatably arranged on one side of the base to perform stretch bending on the workpiece to be stretch bent.

[0012] On the other hand, the present invention provides a stretch bending method of a preheating device for stretch bending forming, which is applied to the preheating device for stretch bending forming in any of the above solutions. The stretch bending method of the preheating device for stretch bending forming includes:

[0013] Preheating the workpiece to be stretch bent to a set temperature through the preheating part;

[0014] After the workpiece to be stretch-bent reaches the set temperature, both ends of the workpiece to be stretch-bent are clamped by the first stretch-bending assembly and the second stretch-bending assembly;

[0015] The controller controls the first driving assembly to drive the moving stamping die core to extrude towards the fixed stamping die core so as to stamp the workpiece to be stretch-bent, and the controller controls the first stretch-bending assembly and the second stretch-bending assembly to rotate so as to stretch-bend the workpiece to be stretch-bent;

[0016] After the workpiece to be stretch-bent is stamped and stretch-bent, the controller controls the first driving assembly to drive the moving stamping die core away from the fixed stamping die core;

[0017] The workpiece to be stretch-bent is taken out from the first stretch-bending assembly and the second stretch-bending assembly, and quality inspection is carried out on the workpiece to be stretch-bent.

[0018] As an alternative technical solution of the stretch-bending method of the stretch-bending forming preheating device, preheating the workpiece to be stretch-bent to the set temperature by the preheating part includes:

[0019] Placing the workpiece to be stretch-bent in the heat insulation board of the preheating part;

[0020] According to the thickness of the workpiece to be stretch-bent, the controller sets the preheating temperature and the preheating time;

[0021] The controller controls the heater of the preheating part to preheat the workpiece to be stretch-bent to the set temperature.

[0022] As an alternative technical solution of the stretch-bending method of the stretch-bending forming preheating device, according to the thickness of the workpiece to be stretch-bent, setting the preheating temperature and the preheating time by the controller includes:

[0023] When the thickness of the workpiece to be stretch-bent is 3 mm - 5 mm, the preheating time is 15 min - 20 min;

[0024] When the thickness of the workpiece to be stretch-bent is 5 mm - 8 mm, the preheating time is 20 min - 30 min.

[0025] The beneficial effects of the present invention are:

[0026] The present invention provides a preheating device for stretch-bending forming. The preheating device for stretch-bending forming includes a base, a preheating part, a stamping part, a stretch-bending part and a controller. Among them, the stamping part includes a first driving assembly, a moving stamping die core and a fixed stamping die core; the stretch-bending part includes a first stretch-bending assembly and a second stretch-bending assembly rotatably arranged on both sides of the base. By using the preheating device for stretch-bending forming of the present invention, the workpiece to be stretch-bent can be preheated by the preheating part before stretch-bending. Subsequently, after the preheating is completed, the workpiece to be stretch-bent is driven by the first driving assembly to squeeze the moving stamping die core against the fixed stamping die core, so as to realize stamping on the workpiece to be stretch-bent. At the same time, the workpiece to be stretch-bent is stretch-bent by the first stretch-bending assembly and the second stretch-bending assembly, so as to achieve the purpose of stretch-bending the workpiece to be stretch-bent, thereby avoiding the problem that the workpiece to be stretch-bent is prone to springback due to excessive rigidity during direct stretch-bending. At the same time, during stamping, the workpiece to be stretch-bent can be continuously shaped after stretch-bending; and, by setting the controller, it can control the operation of the preheating part, the first driving assembly, the first stretch-bending assembly and the second stretch-bending assembly, improving the intelligent degree of the preheating device for stretch-bending forming. By using the preheating device for stretch-bending forming of the present invention, the problem that the existing preheating device for stretch-bending forming lacks an effective preheating link, resulting in springback during stretch-bending operation, is effectively solved. Brief Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of the preheating device for stretch-bending forming in an embodiment of the present invention;

[0028] Figure 2 is a schematic structural diagram of the preheating device for stretch-bending forming in another angle in an embodiment of the present invention;

[0029] Figure 3 is Figure 2 a partial enlarged view of part A in

[0030] Figure 4 is Figure 2 a partial enlarged view of part B in

[0031] Figure 5 is a schematic structural diagram of the base, the preheating part, the stamping part and the controller in an embodiment of the present invention.

[0032] In the figure:

[0033] 1. Base; 2. Preheating section; 21. Heat insulation plate; 22. Refractory layer; 23. Heater body; 24. Heating wire; 3. Stamping section; 31. Driving part; 32. Pressure sensor; 33. Pushing part; 34. Moving stamping die core; 35. Activity cavity; 36. Guide rod; 37. Spring; 38. First heating part; 39. Fixed stamping die core; 40. Second heating part; 4. Stretch bending section; 41. Pulling arm; 42. Second driving assembly; 43. Rotating shaft; 44. Tension sensor; 45. Clamping part; 451. First clamping plate; 452. Second clamping plate; 453. Fastening piece; 46. Third hydraulic push rod; 5. Controller. Detailed implementation manner

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature being "above", "above" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "below" and "under" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the first feature has a lower horizontal height than the second feature.

[0036] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0037] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where like or similar reference numerals denote like or similar elements or elements having like or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only for explaining the present invention and should not be construed as limiting the present invention.

[0038] As Figures 1 to 5 shown, this embodiment provides a stretch-bending forming preheating device, which includes a base 1, a preheating part 2, a stamping part 3, a stretch-bending part 4, and a controller 5. Among them, the preheating part 2 is arranged on the base 1 and can preheat the workpiece to be stretch-bent; the stamping part 3 includes a first driving assembly, a movable stamping die core 34, and a fixed stamping die core 39. The fixed stamping die core 39 is arranged on the base 1, and the first driving assembly is drivingly connected to the movable stamping die core 34 to stamp the workpiece to be stretch-bent located between the movable stamping die core 34 and the fixed stamping die core 39; the stretch-bending part 4 includes a first stretch-bending assembly and a second stretch-bending assembly rotatably arranged on both sides of the base 1. The first stretch-bending assembly and the second stretch-bending assembly clamp both ends of the workpiece to be stretch-bent respectively and can stretch-bend the workpiece to be stretch-bent; the controller 5 is arranged on the base 1, and the preheating part 2, the first driving assembly, the first stretch-bending assembly, and the second stretch-bending assembly are all communicatively connected to the controller 5, and the controller 5 controls the preheating part 2, the first driving assembly, the first stretch-bending assembly, and the second stretch-bending assembly to work.

[0039] By using the stretch-bending forming preheating device of the present invention, the workpiece to be stretch-bent can be preheated by the preheating part 2 before stretch-bending. Subsequently, the preheated workpiece to be stretch-bent is driven by the first driving assembly to squeeze the movable stamping die core 34 towards the fixed stamping die core 39, so as to realize stamping of the workpiece to be stretch-bent. At the same time, the workpiece to be stretch-bent is stretch-bent by the first stretch-bending assembly and the second stretch-bending assembly, so as to achieve the purpose of stretch-bending the workpiece to be stretch-bent, thereby avoiding the problem that the workpiece to be stretch-bent is prone to springback when directly stretch-bent due to excessive rigidity, and also enabling the workpiece to be stretch-bent to be continuously shaped during stamping; moreover, the controller 5 is provided to control the preheating part 2, the first driving assembly, the first stretch-bending assembly, and the second stretch-bending assembly to work, improving the intelligent degree of the stretch-bending forming preheating device. By using the stretch-bending forming preheating device of the present invention, the problem that the existing stretch-bending forming preheating device lacks an effective preheating link and causes springback during stretch-bending operation is effectively solved.

[0040] In some embodiments, the stretch-bending forming preheating device further includes a first heating element 38 and a second heating element 40. Among them, the first heating element 38 is disposed on the side of the moving stamping die core 34 facing the fixed stamping die core 39, and the second heating element 40 is disposed on the side of the fixed stamping die core 39 facing the moving stamping die core 34. In this way, the first heating element 38 and the second heating element 40 can continuously heat the workpiece to be stretch-bent, avoiding the temperature drop of the workpiece to be stretch-bent during the stamping and stretch-bending processes. Among them, both the first heating element 38 and the second heating element 40 are arc-shaped structures.

[0041] Optionally, a first groove is formed on the side of the moving stamping die core 34 facing the fixed stamping die core 39, and the first heating element 38 is located in the first groove; similarly, a second groove is formed on the side of the fixed stamping die core 39 facing the moving stamping die core 34, and the second heating element 40 is located in the second groove.

[0042] In this embodiment, the preheating part 2 includes a heat insulation plate 21 and a heater. The heat insulation plate 21 is disposed on the base 1. The heat insulation plate 21 has a preheating groove for accommodating the workpiece to be stretch-bent. Among them, the heater is disposed on the heat insulation plate 21, and the controller 5 is electrically connected to the heater. The controller 5 is used to control the heater to preheat the workpiece to be stretch-bent located in the preheating groove. The setting of the heat insulation plate 21 can play a role in heat insulation. Among them, the heat insulation plate 21 includes but is not limited to a heat insulation ceramic plate.

[0043] Furthermore, the preheating part 2 further includes a refractory layer 22. The heater includes a heating wire 24 and a heater body 23. Among them, the heater body 23 is disposed on the heat insulation plate 21 and is electrically connected to the heating wire 24. The controller 5 is electrically connected to the heater body 23, so as to control the heater body 23 to heat the workpiece to be stretch-bent through the heating wire 24; among them, the refractory layer 22 is disposed on the preheating groove, and the heating wire 24 is disposed on the refractory layer 22. With such a setting, the cooperation of the heat insulation plate 21 and the refractory layer 22 can make the preheating part 2 have the functions of fire resistance and heat insulation. Among them, the refractory layer 22 includes but is not limited to a refractory brick cushion layer.

[0044] Optionally, both the heat insulation plate 21 and the refractory layer 22 are U-shaped structures, which facilitates the heat insulation plate 21 to support the refractory layer 22 and facilitates the workpiece to be stretch-bent to be placed in the refractory layer 22.

[0045] In some embodiments, the first driving assembly includes a driving member 31, a pushing member 33, and an elastic connecting member. One end of the elastic connecting member is slidably disposed on the pushing member 33, and the other end is disposed on the moving stamping die core 34. The driving member 31 and the pushing member 33 are drivingly connected to drive the pushing member 33 to drive the moving stamping die core 34 to move. The elastic connecting member includes a guiding rod 36 and a spring 37. There is an activity cavity 35 between the pushing member 33 and the moving stamping die core 34. One end of the guiding rod 36 is slidably disposed on the pushing member 33, and the other end is disposed on the moving stamping die core 34. The spring 37 is located in the activity cavity 35 and is disposed between the pushing member 33 and the moving stamping die core 34. With such a setting, the spring 37 plays an elastic role, so that when the pushing member 33 does not contact the moving stamping die core 34, the moving stamping die core 34 cooperates with the fixed stamping die core 39 through the elastic force of the spring 37 to stamp the workpiece to be bent.

[0046] Among them, the driving member 31 includes, but is not limited to, a first hydraulic push rod.

[0047] Furthermore, the stamping part 3 further includes a pressure sensor 32 disposed between the driving member 31 and the pushing member 33, and the stamping pressure can be detected by using the pressure sensor 32.

[0048] In some embodiments, the first bending assembly includes a pulling arm 41, a second driving assembly 42, and a clamping member 45. The second driving assembly 42 is rotatably disposed on the pulling arm 41, and the second driving assembly 42 and the clamping member 45 are drivingly connected to enable the clamping member 45 to tighten one end of the workpiece to be bent. The pulling arm 41 is rotatably disposed on one side of the base 1, so as to achieve the purpose of bending the workpiece to be bent.

[0049] Optionally, the second driving assembly 42 includes a second hydraulic push rod and a rotating shaft 43. The second hydraulic push rod is rotatably connected to the pulling arm 41 through the rotating shaft 43, and the second hydraulic push rod and the clamping member 45 are drivingly connected to enable the clamping member 45 to tighten one end of the workpiece to be bent, so that when the second hydraulic push rod bends the workpiece to be bent, the telescopic end of the second hydraulic push rod always follows the stress direction of the workpiece to be bent.

[0050] Optionally, the first bending assembly further includes a third hydraulic push rod 46. The pulling arm 41 is rotatably connected to the base 1 through the third hydraulic push rod 46, and the third hydraulic push rod 46 can drive the pulling arm 41 to rotate.

[0051] Optionally, the first bending assembly further includes a tension sensor 44 disposed between the second hydraulic push rod and the clamping member 45, and the tension sensor 44 can detect the tension when the workpiece to be bent is tightened.

[0052] Optionally, the clamping member 45 includes a first clamping plate 451, a second clamping plate 452, and a fastener 453. The first clamping plate 451 is connected to the second hydraulic push rod, and the fastener 453 connects the second clamping plate 452 and the first clamping plate 451 to clamp the workpiece to be bent between the second clamping plate 452 and the first clamping plate 451. Among them, the fastener 453 is a bolt.

[0053] This embodiment also provides a bending method for a bending and forming preheating device, which is applied to the bending and forming preheating device in the above solution. The bending method of the bending and forming preheating device includes: first, preheating the workpiece to be bent to a set temperature through the preheating part 2; then, after the workpiece to be bent reaches the set temperature, clamping both ends of the workpiece to be bent through the first bending assembly and the second bending assembly; then, the controller 5 controls the first driving assembly to drive the moving stamping die core 34 to squeeze towards the fixed stamping die core 39 to stamp the workpiece to be bent, and the controller 5 controls the first bending assembly and the second bending assembly to rotate to bend the workpiece to be bent; after the workpiece to be bent is completed with stamping and bending, the controller 5 controls the first driving assembly to drive the moving stamping die core 34 away from the fixed stamping die core 39; finally, taking out the workpiece to be bent from the first bending assembly and the second bending assembly, and performing quality inspection on the workpiece to be bent. By using the above bending method of the bending and forming preheating device, the workpiece to be bent can be preheated by the preheating part 2 before bending. Subsequently, the preheated workpiece to be bent is driven by the first driving assembly to drive the moving stamping die core 34 to squeeze towards the fixed stamping die core 39, so as to realize stamping the workpiece to be bent. At the same time, the workpiece to be bent is bent by the first bending assembly and the second bending assembly, so as to achieve the purpose of bending the workpiece to be bent, and further avoid the problem that the workpiece to be bent is prone to springback due to excessive rigidity when directly bent. At the same time, during stamping, the workpiece to be bent can also be continuously shaped after bending; and, by setting the controller 5, it can control the preheating part 2, the first driving assembly, the first bending assembly and the second bending assembly to work, improving the intelligent degree of the bending and forming preheating device. It solves the problem that the existing bending and forming preheating device lacks an effective preheating link, resulting in springback during the bending operation. Among them, subsequent quality inspection is carried out on the taken-out workpiece to be bent, such as size measurement and appearance inspection, to ensure that it meets the relevant standards for subway vehicle manufacturing.

[0054] In some embodiments, preheating the workpiece to be bent to a set temperature through the preheating part 2 includes: placing the workpiece to be bent in the heat insulation plate 21 of the preheating part 2; setting the preheating temperature and preheating time through the controller 5 according to the thickness of the workpiece to be bent; and the controller 5 controls the heater of the preheating part 2 to preheat the workpiece to be bent to the set temperature.

[0055] Among them, set the preheating temperature: for high-strength steel with a yield strength commonly used in subway vehicles in the range of 450 MPa - 600 MPa, set the preheating temperature at 300 - 400 °C. Within this temperature range, the plasticity of the steel is significantly improved, and at the same time, adverse changes in the steel microstructure caused by too high temperature can be avoided.

[0056] Furthermore, set the preheating temperature and preheating time through the controller 5, including: when the thickness of the workpiece to be bent is 3 mm - 5 mm, the preheating time is 15 min - 20 min; when the thickness of the workpiece to be bent is 5 mm - 8 mm, the preheating time is 20 min - 30 min. Such settings can ensure that the entire workpiece to be bent reaches the set preheating temperature evenly.

[0057] Optionally, during the stamping operation, set the pressure: the pressure required during stamping is related to factors such as the steel strength, workpiece shape, and size, etc.; generally, for the stamping of high-strength steel for subway vehicles, the pressure is between 200 - 500 tons; for workpieces to be bent with simple shapes and smaller sizes, the required pressure is approximately 200 - 300 tons; for workpieces to be bent with complex shapes and larger sizes, a pressure of 300 - 500 tons is required.

[0058] Operation process: The controller 5 controls the telescopic end of the first hydraulic push rod to extend, and the pressure sensor 32 monitors the pressure change of the telescopic end of the first hydraulic push rod in real time; the pusher 33 moves with the telescopic end of the first hydraulic push rod, and drives the moving stamping die core 34 to extrude towards the fixed stamping die core 39 through the spring 37. The spring 37 plays a role in buffering and adjusting the pressure, avoiding damage to the workpiece to be bent caused by sudden pressure changes; at the same time, the movable cavity 35 controls the first heating element 38 and the second heating element 40 to continuously heat the workpiece to be bent, maintaining the workpiece to be bent within a suitable temperature range and improving its plasticity.

[0059] Optionally, during the bending operation, set the tensile force: the tensile force required for bending is related to factors such as the steel strength, size and shape of the workpiece to be bent, and the bending angle, etc.; usually, the tensile force required for bending is between 50 - 150 tons; for bending with a smaller angle and workpieces to be bent with smaller sizes, the tensile force is approximately 50 - 100 tons; for bending with a larger angle and workpieces to be bent with larger sizes, a tensile force of 100 - 150 tons is required.

[0060] Operation process: While stamping the workpiece to be bent, the controller 5 controls the third hydraulic push rod 46 to drive the pulling arm 41 to rotate, changing the bending angle; at the same time, the controller 5 controls the second hydraulic push rod to perform a stretching operation on the workpiece to be bent, and by precisely controlling the bending angle and the magnitude of the tensile force, the workpiece to be bent gradually reaches the required shape.

[0061] Among them, the heating principle of the preheating part 2 is as follows: The controller 5 controls the heater body 23 according to the set parameters, so that it outputs high-frequency current with a specific frequency and intensity. This high-frequency current acts on the heating wire 24. Based on the principle of electromagnetic induction, the heating wire 24 quickly generates heat. The heat insulation plate 21 and the refractory layer 22 play a heat insulation role during the heating process, reducing heat dissipation, improving the heating efficiency, and ensuring the safety of the operator and surrounding equipment.

[0062] Among them, after the workpiece to be bent and stretched is preheated to the set temperature, both ends of the workpiece to be bent and stretched are accurately placed in the clamping member 45. With the fixation of the clamping member 45, the workpiece to be bent and stretched is firmly fixed to the telescopic end of the second hydraulic push rod, ensuring that the workpiece does not displace during the subsequent bending and stamping processes, and guaranteeing the forming accuracy.

[0063] The working process of the bending and stretching preheating device of the present invention is as follows:

[0064] First, the controller 5 controls the preheating part 2 to preheat the workpiece to be bent and stretched. During operation, the controller 5 stably controls the heater body 23 through the set parameters, so that the heater body 23 outputs high-frequency current and acts on the heating wire 24. After passing through the high-frequency current, the heating wire 24 heats the workpiece to be bent and stretched. During heating, the heat insulation plate 21 and the refractory layer 22 play a heat insulation role. After the workpiece to be bent and stretched is preheated to the set temperature, both ends of the workpiece to be bent and stretched are fixed to the telescopic end of the second hydraulic push rod through the clamping member 45. When bending and stretching the workpiece to be bent and stretched, the controller 5 controls the telescopic end of the first hydraulic push rod, so that the pressure sensor 32 drives the pushing member 33 to move at the telescopic end of the first hydraulic push rod. At the same time, the pushing member 33 drives the moving stamping die core 34 to squeeze towards the fixed stamping die core 39 through the spring 37, so that the workpiece to be bent and stretched is stamped between the moving stamping die core 34 and the fixed stamping die core 39. When the workpiece to be bent and stretched is being stamped, the controller 5 controls the first heating member 38 and the second heating member 40 to heat the workpiece to be bent and stretched. While the workpiece to be bent and stretched is being stamped by the stamping part 3, the controller 5 controls the third hydraulic push rod 46 to drive the pulling arm 41 to rotate. At the same time, the controller 5 also controls the second hydraulic push rod to stretch the workpiece to be bent and stretched. After the stretching is completed, the first hydraulic push rod resets under the action of the controller 5, and the fastener 453 is removed, so that the workpiece to be bent and stretched is removed from the clamping member 45.

[0065] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A stretch-bending forming preheating device, characterized in that Comprising: Base (1); Preheating part (2), arranged on the base (1) and capable of preheating the workpiece to be bent; Stamping part (3), including a first driving component, a movable stamping die core (34) and a fixed stamping die core (39), the fixed stamping die core (39) is arranged on the base (1), and the first driving component is drivingly connected to the movable stamping die core (34) to stamp the workpiece to be bent located between the movable stamping die core (34) and the fixed stamping die core (39); Bending part (4), including a first bending component and a second bending component rotatably arranged on both sides of the base (1), the first bending component and the second bending component respectively clamp both ends of the workpiece to be bent and are capable of bending the workpiece to be bent; Controller (5), arranged on the base (1), the preheating part (2), the first driving component, the first bending component and the second bending component are all communicatively connected to the controller (5), and the controller (5) controls the preheating part (2), the first driving component, the first bending component and the second bending component to work.

2. The stretch-bending forming preheating device according to claim 1, wherein The bending and forming preheating device further includes a first heating element (38) and a second heating element (40), the first heating element (38) is arranged on the side of the movable stamping die core (34) facing the fixed stamping die core (39), the second heating element (40) is arranged on the side of the fixed stamping die core (39) facing the movable stamping die core (34), and both the first heating element (38) and the second heating element (40) are capable of heating the workpiece to be bent.

3. The stretch-bending forming preheating device according to claim 1, wherein, The preheating part (2) includes a heat insulation plate (21) and a heater, the heat insulation plate (21) is arranged on the base (1), the heat insulation plate (21) has a preheating groove for accommodating the workpiece to be bent, the heater is arranged on the heat insulation plate (21), the controller (5) is electrically connected to the heater, and the controller (5) controls the heater to preheat the workpiece to be bent located in the preheating groove.

4. The stretch-bending forming preheating device according to claim 3, wherein The preheating part (2) further includes a refractory layer (22), the heater includes a heating wire (24) and a heater body (23), the heater body (23) is arranged on the heat insulation plate (21) and is electrically connected to the heating wire (24), the refractory layer (22) is arranged on the preheating groove, the heating wire (24) is arranged on the refractory layer (22), and the heating wire (24) is capable of preheating the workpiece to be bent.

5. The stretch-bending forming preheating device according to claim 1, wherein The first driving component includes a driving part (31), a pushing part (33) and an elastic connecting piece, one end of the elastic connecting piece is slidably arranged on the pushing part (33), and the other end is arranged on the movable stamping die core (34), and the driving part (31) is drivingly connected to the pushing part (33) to drive the pushing part (33) to drive the movable stamping die core (34) to move.

6. The stretch-bending forming preheating device according to claim 5, wherein, The stamping part (3) further includes a pressure sensor (32) disposed between the driving member (31) and the pushing member (33), and the pressure sensor (32) is used to detect the stamping pressure.

7. The stretch-bending forming preheating device according to claim 1, wherein, The first stretch-bending assembly includes a stretching arm (41), a second driving assembly (42) and a clamping member (45). The second driving assembly (42) is rotatably disposed on the stretching arm (41). The second driving assembly (42) is drivingly connected to the clamping member (45) so that the clamping member (45) tightens one end of the workpiece to be stretch-bent. The stretching arm (41) is rotatably disposed on one side of the base (1) to perform stretch-bending on the workpiece to be stretch-bent.

8. A stretch-bending method of a stretch-bending forming preheating device, characterized in that, Applied to the stretch-bending preheating device according to any one of claims 1-7, the stretch-bending method of the stretch-bending preheating device includes: Preheating the workpiece to be stretch-bent to a set temperature by the preheating part (2); After the workpiece to be stretch-bent reaches the set temperature, clamping both ends of the workpiece to be stretch-bent by the first stretch-bending assembly and the second stretch-bending assembly; The controller (5) controls the first driving assembly to drive the movable stamping die core (34) to extrude towards the fixed stamping die core (39) to stamp the workpiece to be stretch-bent, and the controller (5) controls the first stretch-bending assembly and the second stretch-bending assembly to rotate to perform stretch-bending on the workpiece to be stretch-bent; After the workpiece to be stretch-bent is stamped and stretch-bent, the controller (5) controls the first driving assembly to drive the movable stamping die core (34) away from the fixed stamping die core (39); Taking out the workpiece to be stretch-bent from the first stretch-bending assembly and the second stretch-bending assembly, and performing quality inspection on the workpiece to be stretch-bent.

9. The stretch-bending method of the stretch-bending preheating device according to claim 8, characterized in that Preheating the workpiece to be stretch-bent to a set temperature by the preheating part (2) includes: Placing the workpiece to be stretch-bent in the heat insulation plate (21) of the preheating part (2); Setting the preheating temperature and preheating time by the controller (5) according to the thickness of the workpiece to be stretch-bent; The controller (5) controls the heater of the preheating part (2) to preheat the workpiece to be stretch-bent to the set temperature.

10. The stretch-bending method of the stretch-bending forming preheating device according to claim 9, characterized in that Setting the preheating temperature and preheating time by the controller (5) according to the thickness of the workpiece to be stretch-bent includes: When the thickness of the workpiece to be stretch-bent is 3mm - 5mm, the preheating time is 15min - 20min; When the thickness of the workpiece to be stretch-bent is 5mm - 8mm, the preheating time is 20min - 30min.

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