Bilateral dieless forming and temperature control system and method for metal difficult to deform

Abstract

The invention discloses a double-side dieless forming and temperature control system and method for metal difficult to deform, the system comprises a part restraining mechanism, a main industrial intelligent robot, an auxiliary industrial intelligent robot, a main end effector and an auxiliary end effector, the main end effector has a heating function, and the auxiliary end effector has a temperature field monitoring function. According to the double-side die-free forming and temperature control system and method for the difficult-to-deform metal, on the basis of metal hot working and temperature field regulation and control, temperature-deformation coupling control is achieved through work hardening, dynamic recovery and dynamic recrystallization softening processes, plate parts are actively heated in the forming process, the temperature field can be monitored in real time, and the forming quality is improved. By dynamically adjusting the heating temperature and the feeding speed of the robot, the strain rate of a plate part can be kept at a low level, meanwhile, the rebound angle of difficult-to-deform metal plates such as titanium alloy and high-strength steel can be controlled within 1 degree, the ductility of the formed part is improved by about two times, and the forming performance of the part is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of metal moldless forming technology, and in particular relates to a double-sided moldless forming and temperature control system and method for difficult-to-deform metals. Background Technology

[0002] With the development of high-end manufacturing, the demand for high-strength, high-precision, and lightweight structural components for products such as space shuttles, high-speed trains, and launch vehicles is constantly increasing. Metal dieless forming technology is being increasingly applied to the manufacturing processes of these products. Relying on the development of intelligent robot technology, its working principle is as follows: the end effector of an intelligent robot applies external force to the metal component, thereby causing plastic deformation.

[0003] Moldless forming is divided into single-sided forming and double-sided forming. Single-sided forming technology has been studied in depth and has achieved certain results, enabling rapid forming of some sheet metal parts. However, single-sided forming technology also has certain drawbacks. Due to its single-sided processing attribute, it cannot manufacture parts with complex shapes, and its effect is poor in areas with abrupt changes in shape. It also suffers from severe thickness loss, which significantly affects the quality of the parts.

[0004] Compared to single-sided forming, double-sided forming offers the advantage of processing on both sides and greater processing freedom, enabling the machining of more complex parts. However, double-sided forming technology is still in its early stages and cannot yet achieve precision forming of large-scale parts. Furthermore, for metals with high surface hardness, springback issues are prone to occur during processing, resulting in poor forming effects and low plasticity of the finished parts. This is closely related to the high strain rate during metal forming.

[0005] Chinese patent application CN110773629A discloses a moldless forming process and apparatus, belonging to the double-sided forming technology. It first pre-processes the general shape of the part through a multi-point forming process to ensure sufficient material storage in each area of ​​the part, and then performs moldless forming to achieve the final shape and size. However, while this method avoids excessive thinning in local areas of the part, it lacks monitoring of the temperature field during processing and fails to solve the springback problem of difficult-to-deform metals. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a double-sided moldless forming and temperature control system and method for difficult-to-deform metals. Based on metal hot working and temperature field regulation, it utilizes work hardening and dynamic recovery, dynamic recrystallization softening processes to achieve temperature-deformation coupling control. During the forming process, the sheet metal parts are actively heated, and the temperature field can be monitored in real time. By dynamically adjusting the heating temperature and robot feed speed, the strain rate of the sheet metal parts can be kept at a low level. At the same time, the springback angle of difficult-to-deform metal sheets such as titanium alloys and high-strength steel can be controlled within 1°, increasing the elongation of the formed parts by about 2 times and significantly improving the forming performance of the parts.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a double-sided moldless forming and temperature control system for difficult-to-deform metals, comprising a part constraint mechanism, a main industrial intelligent robot, a secondary industrial intelligent robot, a main end effector, and a secondary end effector; the part constraint mechanism is used to constrain and fix sheet metal parts; the main industrial intelligent robot and the secondary industrial intelligent robot are respectively arranged on both sides of the sheet metal parts; the main end effector is mounted on the main industrial intelligent robot and has a heating function; the secondary end effector is mounted on the secondary industrial intelligent robot and has a temperature field monitoring function.

[0008] The main end effector includes a main actuator base, an infrared laser heater, a first main connecting rod, a first main processing head, a first main force-applying ball, a second main connecting rod, a second main processing head, a second main force-applying ball, and a main drive motor; the first main connecting rod, the first main processing head, and the first main force-applying ball are connected in series to form a first spindle unit, which is connected to the arm of the main industrial intelligent robot through the first main connecting rod; the main drive motor, the second main connecting rod, the second main processing head, and the second main force-applying ball are connected in series to form a first moving unit; the infrared laser heater, the first spindle unit, and the first moving unit are arranged side by side on the main actuator base.

[0009] The secondary end effector includes a secondary actuator base, an infrared thermal imager, a first secondary connecting rod, a first secondary processing head, a first secondary force-applying ball bearing, a second secondary connecting rod, a second secondary processing head, a second secondary force-applying ball bearing, and a secondary drive motor; the first secondary connecting rod, the first secondary processing head, and the first secondary force-applying ball bearing are connected in series to form a second spindle unit, which is connected to the arm of the secondary industrial intelligent robot through the first secondary connecting rod; the secondary drive motor, the second secondary connecting rod, the second secondary processing head, and the second secondary force-applying ball bearing are connected in series to form a second moving unit; the infrared thermal imager, the second spindle unit, and the second moving unit are arranged side by side on the secondary actuator base.

[0010] A method for double-sided moldless forming of refractory metals, employing the aforementioned double-sided moldless forming and temperature control system for refractory metals, specifically: ① First, the first main force-applying ball of the first spindle unit acts as the punch, and the first auxiliary force-applying ball of the second spindle unit and the second auxiliary force-applying ball of the second moving unit cooperate to act as the die. The punch is moved using a CNC layer-by-layer forming method. During this process, the central axis of the second spindle unit and the second moving unit remains parallel to the central axis of the first spindle unit. The first auxiliary force-applying ball of the second spindle unit and the second auxiliary force-applying ball of the second moving unit remain tangent to the theoretical surface of the part thickness offset by the punch trajectory surface of the first spindle unit. After processing one layer, the first auxiliary force-applying ball of the second spindle unit acts as the punch, and the first main force-applying ball of the first spindle unit and the second main force-applying ball of the first moving unit cooperate to act as the die. The punch is moved again using a CNC layer-by-layer forming method, and the layer of the sheet metal part that has been formed is formed again by reverse forming. The above process is repeated until all layers are processed. ② After all layers of the sheet metal part have been processed once, replace the first main machining head and the first main force-applying ball on the first spindle unit, the second main machining head and the second main force-applying ball on the first moving unit, the first auxiliary machining head and the first auxiliary force-applying ball on the second spindle unit, and the second auxiliary machining head and the second auxiliary force-applying ball on the second moving unit, and replace them all with smaller machining heads and force-applying balls. Then perform all layers of processing again. Repeat the above process until the sheet metal part reaches the target shape and size. ③ During the forming process of sheet metal parts, an infrared laser heater heats the processing area, while an infrared thermal imager monitors the temperature field of the heated area in real time. The computer automatically determines the real-time strain rate of the sheet metal parts based on the material type and real-time temperature data. When the strain rate is too high, the laser power of the infrared laser heater is increased to raise the temperature of the sheet metal parts, thereby promoting the softening process, or the feed speed of the main and auxiliary industrial intelligent robots is reduced until the strain rate of the sheet metal parts drops to the set range. When the strain rate is too low, the laser power of the infrared laser heater is reduced to lower the temperature of the sheet metal parts, thereby promoting the hardening process, or the feed speed of the main and auxiliary industrial intelligent robots is increased until the strain rate of the sheet metal parts rises to the set range.

[0011] The beneficial effects of this invention are: The present invention relates to a double-sided moldless forming and temperature control system and method for difficult-to-deform metals. Based on metal hot working and temperature field regulation, it utilizes work hardening and dynamic recovery, dynamic recrystallization softening processes to achieve temperature-deformation coupling control. During the forming process, the sheet metal parts are actively heated, and the temperature field can be monitored in real time. By dynamically adjusting the heating temperature and robot feed speed, the strain rate of the sheet metal parts can be kept at a low level. At the same time, the springback angle of difficult-to-deform metal sheets such as titanium alloys and high-strength steel can be controlled within 1°, increasing the elongation of the formed parts by about 2 times and significantly improving the forming performance of the parts. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structural principle of a double-sided moldless forming and temperature control system for difficult-to-deform metals according to the present invention. Figure 2 This is a schematic diagram of the main end effector of the present invention; Figure 3 This is a schematic diagram of the secondary end effector of the present invention. In the diagram, 1—part constraint mechanism, 2—main industrial intelligent robot, 3—auxiliary industrial intelligent robot, 4—main end effector, 5—auxiliary end effector, 6—sheet metal part, 7—main actuator base, 8—infrared laser heater, 9—first main connecting rod, 10—first main machining head, 11—first main force-applying ball, 12—second main connecting rod, 13—second main machining head, 14—second main force-applying ball, 15—main drive motor, 16—first spindle unit, 17—first moving unit, 18—auxiliary actuator base, 19—infrared thermal imager, 20—first auxiliary connecting rod, 21—first auxiliary machining head, 22—first auxiliary force-applying ball, 23—second auxiliary connecting rod, 24—second auxiliary machining head, 25—second auxiliary force-applying ball, 26—auxiliary drive motor, 27—second spindle unit, 28—second moving unit. Detailed Implementation

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0014] like Figures 1-3 As shown, a double-sided moldless forming and temperature control system for difficult-to-deform metals includes a part constraint mechanism 1, a main industrial intelligent robot 2, a secondary industrial intelligent robot 3, a main end effector 4, and a secondary end effector 5. The part constraint mechanism 1 is used to constrain and fix a sheet metal part 6. The main industrial intelligent robot 2 and the secondary industrial intelligent robot 3 are respectively arranged on both sides of the sheet metal part 6. The main end effector 4 is mounted on the main industrial intelligent robot 2 and has a heating function. The secondary end effector 5 is mounted on the secondary industrial intelligent robot 3 and has a temperature field monitoring function.

[0015] The main end effector 4 includes a main actuator base 7, an infrared laser heater 8, a first main connecting rod 9, a first main processing head 10, a first main force-applying ball 11, a second main connecting rod 12, a second main processing head 13, a second main force-applying ball 14, and a main drive motor 15; the first main connecting rod 9, the first main processing head 10, and the first main force-applying ball 11 are connected in series to form a first spindle unit 16, which is connected to the arm of the main industrial intelligent robot 2 through the first main connecting rod 9; the main drive motor 15, the second main connecting rod 12, the second main processing head 13, and the second main force-applying ball 14 are connected in series to form a first moving unit 17; the infrared laser heater 8, the first spindle unit 16, and the first moving unit 17 are arranged side by side on the main actuator base 7.

[0016] The secondary end effector 5 includes a secondary actuator base 18, an infrared thermal imager 19, a first secondary connecting rod 20, a first secondary processing head 21, a first secondary force-applying ball 22, a second secondary connecting rod 23, a second secondary processing head 24, a second secondary force-applying ball 25, and a secondary drive motor 26; the first secondary connecting rod 20, the first secondary processing head 21, and the first secondary force-applying ball 22 are connected in series to form a second spindle unit 27, which is connected to the arm of the secondary industrial intelligent robot 3 through the first secondary connecting rod 20; the secondary drive motor 26, the second secondary connecting rod 23, the second secondary processing head 24, and the second secondary force-applying ball 25 are connected in series to form a second moving unit 28; the infrared thermal imager 19, the second spindle unit 27, and the second moving unit 28 are arranged side by side on the secondary actuator base 18.

[0017] A method for double-sided moldless forming of refractory metals, employing the aforementioned double-sided moldless forming and temperature control system for refractory metals, specifically: ① First, the first main force-applying ball 11 of the first spindle unit 16 acts as the punch, and the first auxiliary force-applying ball 22 of the second spindle unit 27 and the second auxiliary force-applying ball 25 of the second moving unit 28 cooperate to act as the die. The punch is moved by a CNC layer-by-layer forming method. During this process, the central axis of the second spindle unit 27 and the second moving unit 28 remains parallel to the central axis of the first spindle unit 16. The first auxiliary force-applying ball 22 of the second spindle unit 27 and the second auxiliary force-applying ball 25 of the second moving unit 28 are also parallel to each other. The theoretical profile of the part thickness offset by the punch trajectory surface of the first spindle unit 16 is always tangent to it. After processing one layer, the first set of force-applying balls 22 of the second spindle unit 27 becomes the punch, and the first main force-applying ball 11 of the first spindle unit 16 and the second main force-applying ball 14 of the first moving unit 17 cooperate to act as the die. The punch continues to move in a CNC layer-by-layer forming manner, and the layer that has been formed on the sheet metal part 6 is formed again by reverse forming. The above process is repeated until all layers are processed. ② After the sheet metal part 6 has completed the processing of all layers, the first main machining head 10 and the first main force-applying ball 11 on the first spindle unit 16, the second main machining head 13 and the second main force-applying ball 14 on the first moving unit 17, the first auxiliary machining head 21 and the first auxiliary force-applying ball 22 on the second spindle unit 27, and the second auxiliary machining head 24 and the second auxiliary force-applying ball 25 on the second moving unit 28 are all replaced with smaller machining heads and force-applying balls. Then, the processing of all layers is performed again. The above process is repeated until the sheet metal part 6 reaches the target shape and size. In this embodiment, the springback angle of the formed sheet metal part 6 is <1°. ③ During the forming process of sheet metal part 6, the processing area is heated by infrared laser heater 8, and the temperature field of the heated area is monitored in real time by infrared thermal imager 19. The computer automatically determines the real-time strain rate of sheet metal part 6 based on the material type of sheet metal part 6 and the real-time temperature data. When the strain rate is too high, the laser power of infrared laser heater 8 is increased to raise the temperature of sheet metal part 6 to promote the softening process, or the feed speed of main industrial intelligent robot 2 and auxiliary industrial intelligent robot 3 is reduced until the strain rate of sheet metal part 6 drops to the set range. When the strain rate is too low, the laser power of infrared laser heater 8 is reduced to lower the temperature of sheet metal part 6 to promote the hardening process, or the feed speed of main industrial intelligent robot 2 and auxiliary industrial intelligent robot 3 is increased until the strain rate of sheet metal part 6 rises to the set range. In this embodiment, the heating temperature setting value of sheet metal part 6 is 600℃~900℃, and the strain rate setting range of sheet metal part 6 is 0.01s. -1 ~0.1s -1 .

[0018] Specifically, the hot working deformation of metallic materials involves two processes: first, strain hardening, where the resistance to deformation gradually increases with the amount of deformation, leading to an increase in dislocation density and making it very difficult for the metallic material to undergo further plastic deformation; and second, high-temperature softening, where strain energy begins to be stored inside the metallic material after deformation, and dynamic recrystallization and dynamic recovery occur at high temperatures, causing the dislocation density to decrease rapidly and resulting in a significant increase in the plasticity of the material.

[0019] The solutions in the embodiments are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the present invention are included in the scope of protection of the present invention.

Claims

1. A double-sided moldless forming and temperature control system for difficult-to-deform metals, characterized in that: The system includes a part constraint mechanism, a main industrial intelligent robot, a secondary industrial intelligent robot, a main end effector, and a secondary end effector. The part constraint mechanism is used to constrain and fix the sheet metal part. The main industrial intelligent robot and the secondary industrial intelligent robot are respectively arranged on both sides of the sheet metal part. The main end effector is mounted on the main industrial intelligent robot and has a heating function. The secondary end effector is mounted on the secondary industrial intelligent robot and has a temperature field monitoring function.

2. The double-sided moldless forming and temperature control system for difficult-to-deform metals according to claim 1, characterized in that: The main end effector includes a main actuator base, an infrared laser heater, a first main connecting rod, a first main processing head, a first main force-applying ball, a second main connecting rod, a second main processing head, a second main force-applying ball, and a main drive motor; the first main connecting rod, the first main processing head, and the first main force-applying ball are connected in series to form a first spindle unit, which is connected to the arm of the main industrial intelligent robot through the first main connecting rod; the main drive motor, the second main connecting rod, the second main processing head, and the second main force-applying ball are connected in series to form a first moving unit; the infrared laser heater, the first spindle unit, and the first moving unit are arranged side by side on the main actuator base.

3. The double-sided moldless forming and temperature control system for difficult-to-deform metals according to claim 1, characterized in that: The secondary end effector includes a secondary actuator base, an infrared thermal imager, a first secondary connecting rod, a first secondary processing head, a first secondary force-applying ball bearing, a second secondary connecting rod, a second secondary processing head, a second secondary force-applying ball bearing, and a secondary drive motor; the first secondary connecting rod, the first secondary processing head, and the first secondary force-applying ball bearing are connected in series to form a second spindle unit, which is connected to the arm of the secondary industrial intelligent robot through the first secondary connecting rod; the secondary drive motor, the second secondary connecting rod, the second secondary processing head, and the second secondary force-applying ball bearing are connected in series to form a second moving unit; the infrared thermal imager, the second spindle unit, and the second moving unit are arranged side by side on the secondary actuator base.

4. A method for double-sided moldless forming of difficult-to-deform metals, employing the double-sided moldless forming and temperature control system for difficult-to-deform metals as described in claim 1, characterized in that, Specifically: ① First, the first main force-applying ball of the first spindle unit acts as the punch, and the first auxiliary force-applying ball of the second spindle unit and the second auxiliary force-applying ball of the second moving unit cooperate to act as the die. The punch is moved by CNC layer-by-layer forming. During this process, the central axis of the second spindle unit and the second moving unit is always parallel to the central axis of the first spindle unit. The first auxiliary force-applying ball of the second spindle unit and the second auxiliary force-applying ball of the second moving unit are always tangent to the theoretical surface of the part thickness offset by the punch trajectory surface of the first spindle unit. After processing one layer, the first auxiliary force-applying ball of the second spindle unit acts as the punch, and the first main force-applying ball of the first spindle unit and the second main force-applying ball of the first moving unit cooperate to act as the die. The punch is moved by CNC layer-by-layer forming again to perform reverse forming on the layer of the sheet metal part that has been formed. Repeat the above process until all layers have been processed. ② After all layers of the sheet metal part have been processed once, replace the first main machining head and the first main force-applying ball on the first spindle unit, the second main machining head and the second main force-applying ball on the first moving unit, the first auxiliary machining head and the first auxiliary force-applying ball on the second spindle unit, and the second auxiliary machining head and the second auxiliary force-applying ball on the second moving unit, and replace them all with smaller machining heads and force-applying balls. Then perform all layers of processing again. Repeat the above process until the sheet metal part reaches the target shape and size. ③ During the forming process of sheet metal parts, an infrared laser heater heats the processing area, while an infrared thermal imager monitors the temperature field of the heated area in real time. The computer automatically determines the real-time strain rate of the sheet metal parts based on the material type and real-time temperature data. When the strain rate is too high, the laser power of the infrared laser heater is increased to raise the temperature of the sheet metal parts, thereby promoting the softening process, or the feed speed of the main and auxiliary industrial intelligent robots is reduced until the strain rate of the sheet metal parts drops to the set range. When the strain rate is too low, the laser power of the infrared laser heater is reduced to lower the temperature of the sheet metal parts, thereby promoting the hardening process, or the feed speed of the main and auxiliary industrial intelligent robots is increased until the strain rate of the sheet metal parts rises to the set range.

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